1) The document analyzes radioactive contamination of aquatic ecosystems following the Chernobyl nuclear accident, focusing on accumulation of radionuclides in aquatic biota.
2) Radionuclide levels remained highly elevated in the Chernobyl cooling pond ecosystem for years after the accident, with bottom sediments, aquatic plants, and mollusks showing particularly high contamination.
3) Predatory fish species in the cooling pond and other water bodies accumulated much higher levels of radiocesium than non-predatory species, demonstrating the effect of trophic transfer.
L’OLIGOTROFITZACIÓ CULTURAL DELS RIUS OCCIDENTALS I ELS CANVIS A L’ECOSISTEMA FLUVIAL: EL CAS DE L’EBRE.
Seminari Dept Ecologia - UB per Carles Ibañez (IRTA-Sant Carles de la Ràpita) el 18/01/2013
This document summarizes a study on the accumulation of mercury in marine biota in Buyat Bay, Indonesia. The study found mercury in all sampled organisms, with concentrations varying by species and trophic level. Mercury concentrations were lowest in primary producers like seaweed and sea grass, and highest in carnivorous fish like the honeycomb grouper, with levels over 350 parts per billion. The results indicate biomagnification of mercury up the food chain, especially in the form of methylmercury, the most toxic and bioaccumulative form, posing risks to human health.
1) The contamination of the marine environment near Fukushima occurred through atmospheric fallout into the sea and discharge of contaminated water.
2) Japanese authorities MEXT and TEPCO are conducting sea water sampling with MEXT sampling in a transect 30 km offshore and TEPCO sampling at nearshore and offshore stations.
3) The highest levels of radioactive contamination are still being measured close to the coast but concentrations 30 km offshore are decreasing over time and are expected to continue decreasing through dilution and dispersion by ocean currents if no additional releases occur.
The document discusses using ammonium nitrate injections to enhance monitored natural attenuation (MNA) at a site with dissolved petroleum contamination. Baseline testing found the aquifer had a microbial population but limited nutrients and terminal electron acceptors. Approximately 116 pounds of ammonium nitrate fertilizer was injected, providing a source of nitrate to drive biodegradation. Monitoring after injection found increased biological activity and degradation rates, showing nitrate addition can accelerate MNA by stimulating microbial growth where nutrients were previously limited.
his study investigated the microbial community in a full scale anaerobic baffled reactor and sequencing batch reactor system for oil-produced water treatment in summer and winter. The community structures of fungi and bacteria were analyzed through polymerase chain reaction–denaturing gradient gel electrophoresis and Illumina high-throughput sequencing, respectively. Chemical oxygen demand effluent concentration achieved lower than 50 mg/L level after the system in both summer and winter, however, chemical oxygen demand removal rates after anaerobic baffled reactor treatment system were significant higher in summer than that in winter, which conformed to the microbial community diversity. Saccharomycotina, Fusarium, and Aspergillus were detected in both anaerobic baffled reactor and sequencing batch reactor during summer and winter. The fungal communities in anaerobic baffled reactor and sequencing batch reactor were shaped by seasons and treatment units, while there was no correlation between abundance of fungi and chemical oxygen demand removal rates. Compared to summer, the total amount of the dominant hydrocarbon degrading bacteria decreased by 10.2% in anaerobic baffled reactor, resulting in only around 23% of chemical oxygen demand was removed in winter. Although microbial community significantly varied in the three parallel sulfide reducing bacteria, the performance of these bioreactors had no significant difference between summer and winter.
137cs, 239,240 pu and241am in bottom sediments and surface water of lake paij...trabajomuestreo
This study analyzed 137Cs, 239,240Pu, and 241Am in sediment and surface water samples from Lake Paijanne in Finland. The average activities of 239,240Pu and 241Am in sediment profiles were 45 ± 15 Bq/m2 and 20 ± 7 Bq/m2, respectively. The average 241Am/239,240Pu ratio in sediments was 0.45 ± 0.14 and decreased with depth. The average activities of 239,240Pu and 241Am in surface water samples were 4.9 ± 0.9 mBq/m3 and 4.1 ± 0.2 mBq/m3, respectively, with a 241Am/239,240Pu ratio of 0
L’OLIGOTROFITZACIÓ CULTURAL DELS RIUS OCCIDENTALS I ELS CANVIS A L’ECOSISTEMA FLUVIAL: EL CAS DE L’EBRE.
Seminari Dept Ecologia - UB per Carles Ibañez (IRTA-Sant Carles de la Ràpita) el 18/01/2013
This document summarizes a study on the accumulation of mercury in marine biota in Buyat Bay, Indonesia. The study found mercury in all sampled organisms, with concentrations varying by species and trophic level. Mercury concentrations were lowest in primary producers like seaweed and sea grass, and highest in carnivorous fish like the honeycomb grouper, with levels over 350 parts per billion. The results indicate biomagnification of mercury up the food chain, especially in the form of methylmercury, the most toxic and bioaccumulative form, posing risks to human health.
1) The contamination of the marine environment near Fukushima occurred through atmospheric fallout into the sea and discharge of contaminated water.
2) Japanese authorities MEXT and TEPCO are conducting sea water sampling with MEXT sampling in a transect 30 km offshore and TEPCO sampling at nearshore and offshore stations.
3) The highest levels of radioactive contamination are still being measured close to the coast but concentrations 30 km offshore are decreasing over time and are expected to continue decreasing through dilution and dispersion by ocean currents if no additional releases occur.
The document discusses using ammonium nitrate injections to enhance monitored natural attenuation (MNA) at a site with dissolved petroleum contamination. Baseline testing found the aquifer had a microbial population but limited nutrients and terminal electron acceptors. Approximately 116 pounds of ammonium nitrate fertilizer was injected, providing a source of nitrate to drive biodegradation. Monitoring after injection found increased biological activity and degradation rates, showing nitrate addition can accelerate MNA by stimulating microbial growth where nutrients were previously limited.
his study investigated the microbial community in a full scale anaerobic baffled reactor and sequencing batch reactor system for oil-produced water treatment in summer and winter. The community structures of fungi and bacteria were analyzed through polymerase chain reaction–denaturing gradient gel electrophoresis and Illumina high-throughput sequencing, respectively. Chemical oxygen demand effluent concentration achieved lower than 50 mg/L level after the system in both summer and winter, however, chemical oxygen demand removal rates after anaerobic baffled reactor treatment system were significant higher in summer than that in winter, which conformed to the microbial community diversity. Saccharomycotina, Fusarium, and Aspergillus were detected in both anaerobic baffled reactor and sequencing batch reactor during summer and winter. The fungal communities in anaerobic baffled reactor and sequencing batch reactor were shaped by seasons and treatment units, while there was no correlation between abundance of fungi and chemical oxygen demand removal rates. Compared to summer, the total amount of the dominant hydrocarbon degrading bacteria decreased by 10.2% in anaerobic baffled reactor, resulting in only around 23% of chemical oxygen demand was removed in winter. Although microbial community significantly varied in the three parallel sulfide reducing bacteria, the performance of these bioreactors had no significant difference between summer and winter.
137cs, 239,240 pu and241am in bottom sediments and surface water of lake paij...trabajomuestreo
This study analyzed 137Cs, 239,240Pu, and 241Am in sediment and surface water samples from Lake Paijanne in Finland. The average activities of 239,240Pu and 241Am in sediment profiles were 45 ± 15 Bq/m2 and 20 ± 7 Bq/m2, respectively. The average 241Am/239,240Pu ratio in sediments was 0.45 ± 0.14 and decreased with depth. The average activities of 239,240Pu and 241Am in surface water samples were 4.9 ± 0.9 mBq/m3 and 4.1 ± 0.2 mBq/m3, respectively, with a 241Am/239,240Pu ratio of 0
This document describes research on nitrogen transformations in aquaponic systems. The objectives were to quantify the impact of physical and chemical variables on nitrogen transformations, evaluate transformations of different nitrogen forms under various conditions, examine ecologically important species, and investigate greenhouse gas emissions. Experiments were conducted with different hydraulic loading rates, pH levels, plant species, and sediment draining frequencies. The results showed that nitrate accumulation was affected by loading rate, pH, and plant uptake rate, while nitrogen loss occurred through denitrification. Microbial analyses provided insight into nitrifying bacteria populations and their role in the nitrogen cycle.
This document summarizes a study that examined the effect of two pesticides, diazinon and glyphosate, on the oxygen consumption of the box mussel Septifer bilocularis. Mussels were exposed to various sublethal concentrations of each pesticide and their oxygen consumption was monitored over time. Results showed that low concentrations tended to increase oxygen consumption, while higher concentrations decreased it. Specifically, concentrations of 6 and 30 ppm diazinon and 720 and 960 ppm glyphosate were found to have a statistically significant effect on reducing the mussels' oxygen consumption. The study provides insight into how these common pesticides may impact the physiology and energy requirements of non-target marine organisms.
This document summarizes a seminar on using isotopes in soil and plant studies. It discusses the history and units of radioactivity, different types of isotopes, and monitoring instruments like Geiger counters. Key applications mentioned include using isotopes as tracers to study groundwater movement, fertilizer usage, soil carbon and nitrogen cycling, and erosion. The document concludes by outlining some future research areas like using isotope signatures to study plant silicon, heavy metal cycling and accumulation, and the effects of biochar application.
This document summarizes a study of the regeneration zone in a wastewater treatment plant in Liberec, Czech Republic. The regeneration zone has three main functions: 1) regenerating the storage capacity of activated sludge cells, 2) increasing the aerobic sludge age, and 3) bioaugmenting nitrification in situ by supplying substrate for nitrifying bacteria. Experimental results from the plant show that the regeneration zone increased nitrification rates and initially fulfilled its role in bioaugmenting nitrification. However, accidents disrupting the supply of reject water stopped the bioaugmentation and regeneration functions.
Stable oxygen and carbon isotopes can be used as proxies for paleoclimate reconstruction. Oxygen isotopes in carbonate shells vary based on temperature and ice volume, providing information about glacial/interglacial cycles. Carbon isotopes reflect the global carbon cycle and can indicate changes in productivity, circulation, and terrestrial carbon storage over time.
This document summarizes a presentation about using natural CO2 vents as analogues to study potential environmental effects of CO2 leakage from carbon storage. It describes several examples of terrestrial and marine natural CO2 vents, including sites in Germany, Italy, and Japan. Parameters that can be investigated using these analogues include CO2 concentrations, chemical impacts on pH and metal mobilization, and biological impacts on microbes, vegetation, and animals. The presentation emphasizes that natural analogues provide realistic boundary conditions to validate experimental and modeling results and to test monitoring techniques.
Bridgewater (2013) Muddy River BiodiversityAngeline Chen
This study investigates the relationship between microbial biodiversity and sediment contamination in two ponds within the Muddy River system. Willow Pond downstream is known to be contaminated with oil, pesticides and heavy metals, while Ward's Pond upstream has little contamination. Sediment samples from both ponds will be analyzed chemically and microscopically to quantify contaminant levels and compare microbial populations. Previous studies have found microbial indicators can assess water quality and ecosystem health in a simple, inexpensive way. The researchers hypothesize microbial diversity will be lower in Willow Pond's more contaminated sediments.
This document lists numerous publications by Dr. Zwinselman Jan Johan related to negative ion field desorption mass spectrometry and other topics. Many of the publications explore using various mass spectrometry techniques like field desorption, field ionization kinetics, and collisionally activated dissociation to study the fragmentation and ionization of organic and inorganic compounds. The publications span from 1979 to 2000 and were published in journals focused on analytical chemistry, mass spectrometry, and related fields.
2010 - Assessment of advanced wastewater treatments for nitrogen removal sear...WALEBUBLÉ
This document summarizes a study that assessed advanced wastewater treatment plants for nitrogen removal in Spain over 14 months. The study characterized biological communities by identifying and counting protists (ciliates, flagellates, amoeba) and recording physical-chemical parameters. Surprisingly, ciliates were found to be less abundant and diverse than in conventional treatment plants. The aim was to determine potential biological indicators of treatment efficiency, as indicators from conventional plants could not be directly extrapolated to advanced nutrient removal systems with different biological characteristics.
This document summarizes a study examining seasonal patterns of nutrient retention in a restored tidal freshwater stream. The study measured water and nutrient fluxes, estimated ecosystem metabolism through dissolved oxygen patterns, and identified factors controlling nutrient retention. Key results included macro-tidal water exchange driven by river depth, conservative behavior of chloride but retention of nitrogen and phosphorus, and higher retention during periods of lower metabolism in winter months.
This document discusses doping and ion implantation in semiconductor fabrication. It describes how dopants such as boron, arsenic, and phosphorus are introduced through diffusion or ion implantation processes to create n-type and p-type semiconductors. The mathematics of diffusion are presented, including Fick's laws and the solution of the diffusion equation. Experimental setups for diffusion and ion implantation are shown. Ion implantation involves accelerating dopant ions into the semiconductor to reach a projected range and Gaussian distribution. Post-implantation diffusion may be needed to activate the implanted dopants.
DNAPL Remediation with ClO2_UV-published paperDarcy Bye
This study investigated the sorption of PAHs, PCBs, phenols, and BTEX hydrocarbons from groundwater onto a subsoil core sample. It also examined the destruction of these contaminants in ClO2/UV solution systems using methanol as the carrier solvent. Sorption experiments showed the contaminants formed S-type isotherms and could be modeled using the Freundlich equation. Off-site travel times for the contaminants in groundwater ranged from 145 to 80,817 years based on sorption. Treatment with ClO2/UV destroyed 76-98% of the contaminants and produced no dioxins or furans as byproducts, demonstrating this method's potential for remediating recal
This document discusses using the isotopic signatures of carbon and nitrogen in the tissues of blue mussels (Mytilus galloprovincialis) and seaweed (Ulva latuca) to assess the impact of sewage effluent discharge. Samples were collected before and after upgrades to wastewater treatment plants. Results found isotopic signatures in 2001 indicated enrichment from sewage at contaminated sites, but no significant differences in 2015 after treatment upgrades. This suggests upgrades successfully limited sewage impact. Future studies should further examine particulate organic matter sources in coastal ecosystems.
This study investigated the dissolution behavior of various uranyl phosphates under conditions that allow for the formation of uranyl peroxide nanoclusters. Electrospray ionization-mass spectrometry (ESI-MS) was used to detect the presence and stability of nanoclusters over time, while inductively coupled plasma-optical emission spectrometry (ICP-OES) analyzed final uranium concentrations to determine the effect of cations on uranium release. The maximum uranium release occurred at pH 10+ and a 1.00M peroxide concentration, reaching concentrations over 8,000 ppm. Nanoclusters were detected by ESI-MS starting around pH 9 and were stable over a week.
2012 synthesis and photocatalytic application of ternary cu–zn–s nanoparticle...Ngoc Khuong
This document discusses a study on synthesizing and characterizing ternary Cu-Zn-S nanoparticle-sensitized TiO2 nanotube arrays (Cu-Zn-S/TiO2 NTAs) as a novel photocatalyst. Cu-Zn-S nanoparticles were deposited onto TiO2 NTAs using a pulse electrodeposition method. Under simulated solar illumination, the Cu-Zn-S/TiO2 NTAs exhibited significantly enhanced photocatalytic degradation of 2,4-D and 9-AnCOOH pollutants compared to unmodified TiO2 NTAs. After 150 minutes, 100% of 2,4-D was degraded using Cu-Zn-S/TiO2 NTAs compared to 51.8
1) The document discusses the relevance of the carbon-14 isotope in soil sciences. Carbon-14 dating can be used to determine the age of soils up to 60,000 years old.
2) Carbon-14 is produced naturally in the atmosphere and enters the carbon cycle. It can be used to study processes like organic matter decomposition and carbon sequestration in soils over time.
3) Methods described include using carbon-14 labeled plant materials and substrates in laboratory incubations and field experiments to measure the mineralization of organic carbon to carbon dioxide and incorporation into microbial biomass. Collection of evolved carbon dioxide allows quantification of decomposition rates.
Determinar la toxicitat dels sediments en els ecosistemes aquàtics és un repte, i és necessari per a una adequada avaluació del risc toxicològic en aquests ecosistemes. En les darreres dècades s’han estudiat i aplicat diferents eines (ex. tests de laboratori amb diferents concentracions, tests amb l’aigua intersticial, estudis de bioacumulació, índexs de toxicitat). Actualment es recomana l'aplicació conjunta d'eines químiques, ecològiques i toxicològiques per a una adequada avaluació. En aquest treball utilitzem l’aproximació de les Toxic Units, tests de toxicitat amb l’aigua intersticial (Vibrio fischeri, Pseudokirchneriella subcapitata i Daphnia magna) i tests d'exposició amb el sediment (V. fischeri, Chironomus riparius), juntament amb l’estudi de la comunitat d'invertebrats, per detectar respostes a curt i llarg termini en quatre rius de la Península Ibèrica: el Llobregat, l’Ebre, el Xúquer i el Guadalquivir.
by Núria de Castro-Català, Maja Kuzmanovic, Neus Roig, Jordi Sierra, Antoni Ginebreda, Damià Barceló, Sandra Pérez, Mira Petrovic, Yolanda Picó, Marta Schumacher and Isabel Muñoz
SEDIMENT QUALITY ASSESSMENT OF AVARAGERE LAKE, DAVANAGERE CITY - A CASE STUDYAM Publications
Avaragere Lake in Davangere was studied for chemical and physical parameters at five locations, for a period of six months (April 2014 to Sep 2014). Lake has been subjected to human interferences regularly and water quality was to be getting deteriorated profoundly. Major anthropogenic activities practiced in and around the stretch: agriculture, discharging of sewage waste etc was generating serious threat to the biota of the lake by altering the physical, chemical and biological concentration of the lake system. The other possibility is that since there are no major industries in the project area, the major source of organic pollutants is only the domestic source.
Monthly data’s been collected. Different parameters studied were pH, Conductivity, organic carbon, nitrogen, phosphorus, potassium, zinc, copper, iron, organothiophosphate and pyrethroid content. The results obtained from the above study indicate that the water of Avaragere Lake organothiophosphate and pyrethroid content shows very low concentrations even at nanogram. Manganese and iron concentrations of sediment sample in avaragere lake shows high level of pollution and ecological balance of Lake is totally disturbed.
This document summarizes an experimental study on the use of unmodified lignocellulosic fibrous layer of palm tree trunk (ULFPT) as a low-cost biosorbent for removing copper (Cu2+) and zinc (Zn2+) from aqueous solutions. Batch experiments were conducted to investigate the effects of pH, initial metal ion concentration, and contact time on biosorption. Equilibrium data were modeled using Langmuir, Freundlich, Redlich-Peterson, and Temkin isotherm models. The Redlich-Peterson model provided the best fit for Cu2+ and Zn2+ biosorption. The Langmuir model also provided a good fit. Maximum Cu2+ removal (
This document discusses naturally occurring radioactive material (NORM) found in produced water from offshore oil and gas production platforms in the North Sea. It focuses on which radioactive isotopes are present, how they distribute and accumulate in marine ecosystems, and possible environmental consequences. While large amounts of radioactivity are released annually, increases in radioactivity levels are not measurable in North Sea ecosystems. The document concludes there is no evidence NORM from produced water is increasing sediment or organism radioactivity levels or having effects in the region.
ASSESSMENT OF NATURAL RADIOACTIVITY LEVEL IN SHORE SEDIMENT SAMPLES FROM NASS...ijbesjournal
Thirty shore sediment samples taken from the side beach of Lake Nasser in south Arab Republic of Egypt to measuring the terrestrial radionuclides radium-226, thorium-232 and potassium-40 and its associated hazard indices. The activity concentration of natural radionuclides 226Ra,232Th and 40k in shore sediments samples under investigation are ranged from 1.92±0.077 to 17.55±0.676 Bqkg-1 with average value of 5.02±0.194 Bqkg-1, 5.62±0.281 to 28.77±1.441 Bqkg-1 with average value of 13.15±0.641 Bqkg-1 and 123.27±10.604 to 277.38±23.861 Bqkg-1 with average value of 200.26±17.054 Bqkg-1respectively .The radiation hazard indices which resulting from the presence of natural radionuclides in shore sediment samples were calculated and the obtained results indicate that the values of radium equivalent activity varies from 21.85 to 80.04 Bq/kg with average value of 39.25 Bq/kg, representative level index Iˠr varies from 0.16 to 0.58 with average value of 0.29.Absorbed dose rate varies from 10.63 to 37.541 nGy.h−1 with the average value of 18.83 nGy.h−1 . External hazard index Hix varies from 0.059 to 0.216 with average value of 0.105, internal hazard index Hin varies from 0.070 to 0.263 with average value of 0.119, annual outdoor effective dose varied from 0.013 to 0.046 mSvy-1 with average values 0.023 mSvy-1andThe indoor effective dose ranged from 0.052 to 0.184 mSvy-1, with average values 0.092 mSvy-1.
This document describes research on nitrogen transformations in aquaponic systems. The objectives were to quantify the impact of physical and chemical variables on nitrogen transformations, evaluate transformations of different nitrogen forms under various conditions, examine ecologically important species, and investigate greenhouse gas emissions. Experiments were conducted with different hydraulic loading rates, pH levels, plant species, and sediment draining frequencies. The results showed that nitrate accumulation was affected by loading rate, pH, and plant uptake rate, while nitrogen loss occurred through denitrification. Microbial analyses provided insight into nitrifying bacteria populations and their role in the nitrogen cycle.
This document summarizes a study that examined the effect of two pesticides, diazinon and glyphosate, on the oxygen consumption of the box mussel Septifer bilocularis. Mussels were exposed to various sublethal concentrations of each pesticide and their oxygen consumption was monitored over time. Results showed that low concentrations tended to increase oxygen consumption, while higher concentrations decreased it. Specifically, concentrations of 6 and 30 ppm diazinon and 720 and 960 ppm glyphosate were found to have a statistically significant effect on reducing the mussels' oxygen consumption. The study provides insight into how these common pesticides may impact the physiology and energy requirements of non-target marine organisms.
This document summarizes a seminar on using isotopes in soil and plant studies. It discusses the history and units of radioactivity, different types of isotopes, and monitoring instruments like Geiger counters. Key applications mentioned include using isotopes as tracers to study groundwater movement, fertilizer usage, soil carbon and nitrogen cycling, and erosion. The document concludes by outlining some future research areas like using isotope signatures to study plant silicon, heavy metal cycling and accumulation, and the effects of biochar application.
This document summarizes a study of the regeneration zone in a wastewater treatment plant in Liberec, Czech Republic. The regeneration zone has three main functions: 1) regenerating the storage capacity of activated sludge cells, 2) increasing the aerobic sludge age, and 3) bioaugmenting nitrification in situ by supplying substrate for nitrifying bacteria. Experimental results from the plant show that the regeneration zone increased nitrification rates and initially fulfilled its role in bioaugmenting nitrification. However, accidents disrupting the supply of reject water stopped the bioaugmentation and regeneration functions.
Stable oxygen and carbon isotopes can be used as proxies for paleoclimate reconstruction. Oxygen isotopes in carbonate shells vary based on temperature and ice volume, providing information about glacial/interglacial cycles. Carbon isotopes reflect the global carbon cycle and can indicate changes in productivity, circulation, and terrestrial carbon storage over time.
This document summarizes a presentation about using natural CO2 vents as analogues to study potential environmental effects of CO2 leakage from carbon storage. It describes several examples of terrestrial and marine natural CO2 vents, including sites in Germany, Italy, and Japan. Parameters that can be investigated using these analogues include CO2 concentrations, chemical impacts on pH and metal mobilization, and biological impacts on microbes, vegetation, and animals. The presentation emphasizes that natural analogues provide realistic boundary conditions to validate experimental and modeling results and to test monitoring techniques.
Bridgewater (2013) Muddy River BiodiversityAngeline Chen
This study investigates the relationship between microbial biodiversity and sediment contamination in two ponds within the Muddy River system. Willow Pond downstream is known to be contaminated with oil, pesticides and heavy metals, while Ward's Pond upstream has little contamination. Sediment samples from both ponds will be analyzed chemically and microscopically to quantify contaminant levels and compare microbial populations. Previous studies have found microbial indicators can assess water quality and ecosystem health in a simple, inexpensive way. The researchers hypothesize microbial diversity will be lower in Willow Pond's more contaminated sediments.
This document lists numerous publications by Dr. Zwinselman Jan Johan related to negative ion field desorption mass spectrometry and other topics. Many of the publications explore using various mass spectrometry techniques like field desorption, field ionization kinetics, and collisionally activated dissociation to study the fragmentation and ionization of organic and inorganic compounds. The publications span from 1979 to 2000 and were published in journals focused on analytical chemistry, mass spectrometry, and related fields.
2010 - Assessment of advanced wastewater treatments for nitrogen removal sear...WALEBUBLÉ
This document summarizes a study that assessed advanced wastewater treatment plants for nitrogen removal in Spain over 14 months. The study characterized biological communities by identifying and counting protists (ciliates, flagellates, amoeba) and recording physical-chemical parameters. Surprisingly, ciliates were found to be less abundant and diverse than in conventional treatment plants. The aim was to determine potential biological indicators of treatment efficiency, as indicators from conventional plants could not be directly extrapolated to advanced nutrient removal systems with different biological characteristics.
This document summarizes a study examining seasonal patterns of nutrient retention in a restored tidal freshwater stream. The study measured water and nutrient fluxes, estimated ecosystem metabolism through dissolved oxygen patterns, and identified factors controlling nutrient retention. Key results included macro-tidal water exchange driven by river depth, conservative behavior of chloride but retention of nitrogen and phosphorus, and higher retention during periods of lower metabolism in winter months.
This document discusses doping and ion implantation in semiconductor fabrication. It describes how dopants such as boron, arsenic, and phosphorus are introduced through diffusion or ion implantation processes to create n-type and p-type semiconductors. The mathematics of diffusion are presented, including Fick's laws and the solution of the diffusion equation. Experimental setups for diffusion and ion implantation are shown. Ion implantation involves accelerating dopant ions into the semiconductor to reach a projected range and Gaussian distribution. Post-implantation diffusion may be needed to activate the implanted dopants.
DNAPL Remediation with ClO2_UV-published paperDarcy Bye
This study investigated the sorption of PAHs, PCBs, phenols, and BTEX hydrocarbons from groundwater onto a subsoil core sample. It also examined the destruction of these contaminants in ClO2/UV solution systems using methanol as the carrier solvent. Sorption experiments showed the contaminants formed S-type isotherms and could be modeled using the Freundlich equation. Off-site travel times for the contaminants in groundwater ranged from 145 to 80,817 years based on sorption. Treatment with ClO2/UV destroyed 76-98% of the contaminants and produced no dioxins or furans as byproducts, demonstrating this method's potential for remediating recal
This document discusses using the isotopic signatures of carbon and nitrogen in the tissues of blue mussels (Mytilus galloprovincialis) and seaweed (Ulva latuca) to assess the impact of sewage effluent discharge. Samples were collected before and after upgrades to wastewater treatment plants. Results found isotopic signatures in 2001 indicated enrichment from sewage at contaminated sites, but no significant differences in 2015 after treatment upgrades. This suggests upgrades successfully limited sewage impact. Future studies should further examine particulate organic matter sources in coastal ecosystems.
This study investigated the dissolution behavior of various uranyl phosphates under conditions that allow for the formation of uranyl peroxide nanoclusters. Electrospray ionization-mass spectrometry (ESI-MS) was used to detect the presence and stability of nanoclusters over time, while inductively coupled plasma-optical emission spectrometry (ICP-OES) analyzed final uranium concentrations to determine the effect of cations on uranium release. The maximum uranium release occurred at pH 10+ and a 1.00M peroxide concentration, reaching concentrations over 8,000 ppm. Nanoclusters were detected by ESI-MS starting around pH 9 and were stable over a week.
2012 synthesis and photocatalytic application of ternary cu–zn–s nanoparticle...Ngoc Khuong
This document discusses a study on synthesizing and characterizing ternary Cu-Zn-S nanoparticle-sensitized TiO2 nanotube arrays (Cu-Zn-S/TiO2 NTAs) as a novel photocatalyst. Cu-Zn-S nanoparticles were deposited onto TiO2 NTAs using a pulse electrodeposition method. Under simulated solar illumination, the Cu-Zn-S/TiO2 NTAs exhibited significantly enhanced photocatalytic degradation of 2,4-D and 9-AnCOOH pollutants compared to unmodified TiO2 NTAs. After 150 minutes, 100% of 2,4-D was degraded using Cu-Zn-S/TiO2 NTAs compared to 51.8
1) The document discusses the relevance of the carbon-14 isotope in soil sciences. Carbon-14 dating can be used to determine the age of soils up to 60,000 years old.
2) Carbon-14 is produced naturally in the atmosphere and enters the carbon cycle. It can be used to study processes like organic matter decomposition and carbon sequestration in soils over time.
3) Methods described include using carbon-14 labeled plant materials and substrates in laboratory incubations and field experiments to measure the mineralization of organic carbon to carbon dioxide and incorporation into microbial biomass. Collection of evolved carbon dioxide allows quantification of decomposition rates.
Determinar la toxicitat dels sediments en els ecosistemes aquàtics és un repte, i és necessari per a una adequada avaluació del risc toxicològic en aquests ecosistemes. En les darreres dècades s’han estudiat i aplicat diferents eines (ex. tests de laboratori amb diferents concentracions, tests amb l’aigua intersticial, estudis de bioacumulació, índexs de toxicitat). Actualment es recomana l'aplicació conjunta d'eines químiques, ecològiques i toxicològiques per a una adequada avaluació. En aquest treball utilitzem l’aproximació de les Toxic Units, tests de toxicitat amb l’aigua intersticial (Vibrio fischeri, Pseudokirchneriella subcapitata i Daphnia magna) i tests d'exposició amb el sediment (V. fischeri, Chironomus riparius), juntament amb l’estudi de la comunitat d'invertebrats, per detectar respostes a curt i llarg termini en quatre rius de la Península Ibèrica: el Llobregat, l’Ebre, el Xúquer i el Guadalquivir.
by Núria de Castro-Català, Maja Kuzmanovic, Neus Roig, Jordi Sierra, Antoni Ginebreda, Damià Barceló, Sandra Pérez, Mira Petrovic, Yolanda Picó, Marta Schumacher and Isabel Muñoz
SEDIMENT QUALITY ASSESSMENT OF AVARAGERE LAKE, DAVANAGERE CITY - A CASE STUDYAM Publications
Avaragere Lake in Davangere was studied for chemical and physical parameters at five locations, for a period of six months (April 2014 to Sep 2014). Lake has been subjected to human interferences regularly and water quality was to be getting deteriorated profoundly. Major anthropogenic activities practiced in and around the stretch: agriculture, discharging of sewage waste etc was generating serious threat to the biota of the lake by altering the physical, chemical and biological concentration of the lake system. The other possibility is that since there are no major industries in the project area, the major source of organic pollutants is only the domestic source.
Monthly data’s been collected. Different parameters studied were pH, Conductivity, organic carbon, nitrogen, phosphorus, potassium, zinc, copper, iron, organothiophosphate and pyrethroid content. The results obtained from the above study indicate that the water of Avaragere Lake organothiophosphate and pyrethroid content shows very low concentrations even at nanogram. Manganese and iron concentrations of sediment sample in avaragere lake shows high level of pollution and ecological balance of Lake is totally disturbed.
This document summarizes an experimental study on the use of unmodified lignocellulosic fibrous layer of palm tree trunk (ULFPT) as a low-cost biosorbent for removing copper (Cu2+) and zinc (Zn2+) from aqueous solutions. Batch experiments were conducted to investigate the effects of pH, initial metal ion concentration, and contact time on biosorption. Equilibrium data were modeled using Langmuir, Freundlich, Redlich-Peterson, and Temkin isotherm models. The Redlich-Peterson model provided the best fit for Cu2+ and Zn2+ biosorption. The Langmuir model also provided a good fit. Maximum Cu2+ removal (
This document discusses naturally occurring radioactive material (NORM) found in produced water from offshore oil and gas production platforms in the North Sea. It focuses on which radioactive isotopes are present, how they distribute and accumulate in marine ecosystems, and possible environmental consequences. While large amounts of radioactivity are released annually, increases in radioactivity levels are not measurable in North Sea ecosystems. The document concludes there is no evidence NORM from produced water is increasing sediment or organism radioactivity levels or having effects in the region.
ASSESSMENT OF NATURAL RADIOACTIVITY LEVEL IN SHORE SEDIMENT SAMPLES FROM NASS...ijbesjournal
Thirty shore sediment samples taken from the side beach of Lake Nasser in south Arab Republic of Egypt to measuring the terrestrial radionuclides radium-226, thorium-232 and potassium-40 and its associated hazard indices. The activity concentration of natural radionuclides 226Ra,232Th and 40k in shore sediments samples under investigation are ranged from 1.92±0.077 to 17.55±0.676 Bqkg-1 with average value of 5.02±0.194 Bqkg-1, 5.62±0.281 to 28.77±1.441 Bqkg-1 with average value of 13.15±0.641 Bqkg-1 and 123.27±10.604 to 277.38±23.861 Bqkg-1 with average value of 200.26±17.054 Bqkg-1respectively .The radiation hazard indices which resulting from the presence of natural radionuclides in shore sediment samples were calculated and the obtained results indicate that the values of radium equivalent activity varies from 21.85 to 80.04 Bq/kg with average value of 39.25 Bq/kg, representative level index Iˠr varies from 0.16 to 0.58 with average value of 0.29.Absorbed dose rate varies from 10.63 to 37.541 nGy.h−1 with the average value of 18.83 nGy.h−1 . External hazard index Hix varies from 0.059 to 0.216 with average value of 0.105, internal hazard index Hin varies from 0.070 to 0.263 with average value of 0.119, annual outdoor effective dose varied from 0.013 to 0.046 mSvy-1 with average values 0.023 mSvy-1andThe indoor effective dose ranged from 0.052 to 0.184 mSvy-1, with average values 0.092 mSvy-1.
This document describes a scenario to test models of the transport of radioactive contaminants from soil to surface water. It focuses on the wash-off of Cesium-137 and Strontium-90 from two experimental plots near Chernobyl following rainfall. One plot was subjected to heavy rain, the other to snowmelt. The scenario provides data on the initial radionuclide deposition, soil characteristics, and time-varying precipitation. It requests predictions of the vertical distribution of radionuclide forms in the soil, radionuclide concentrations in runoff water, and total radionuclide amounts removed from the soil by runoff. Measured data are available for model validation.
ASSESSMENT OF NATURAL RADIOACTIVITY LEVEL IN SHORE SEDIMENT SAMPLES FROM NASS...ijbesjournal
Thirty shore sediment samples taken from the side beach of Lake Nasser in south Arab Republic of Egypt to
measuring the terrestrial radionuclides radium-226, thorium-232 and potassium-40 and its associated
hazard indices. The activity concentration of natural radionuclides 226Ra,232Th and 40k in shore
sediments samples under investigation are ranged from 1.92±0.077 to 17.55±0.676 Bqkg-1 with average
value of 5.02±0.194 Bqkg-1, 5.62±0.281 to 28.77±1.441 Bqkg-1 with average value of 13.15±0.641 Bqkg-1
and 123.27±10.604 to 277.38±23.861 Bqkg-1 with average value of 200.26±17.054 Bqkg-1respectively
.The radiation hazard indices which resulting from the presence of natural radionuclides in shore sediment
samples were calculated and the obtained results indicate that the values of radium equivalent activity
varies from 21.85 to 80.04 Bq/kg with average value of 39.25 Bq/kg, representative level index Iˠr varies
from 0.16 to 0.58 with average value of 0.29.Absorbed dose rate varies from 10.63 to 37.541 nGy.h−1 with
the average value of 18.83 nGy.h−1 . External hazard index Hix varies from 0.059 to 0.216 with average
value of 0.105, internal hazard index Hin varies from 0.070 to 0.263 with average value of 0.119, annual
outdoor effective dose varied from 0.013 to 0.046 mSvy-1 with average values 0.023 mSvy-1andThe indoor
effective dose ranged from 0.052 to 0.184 mSvy-1, with average values 0.092 mSvy-1.
This study analyzed the distribution of trace metals in sediments and groundwater from three industrial sites along the Providence River: India Point Park (IPP), Public Way (PW), and Oxford Street (OX). Sediment and groundwater samples were collected from multiple depths and analyzed for major and trace metal concentrations. The results showed metal concentrations were elevated above background levels at all sites, with some metals like copper and lead exceeding regulatory guidelines. Concentrations tended to be highest below the water table. OX exhibited the strongest petroleum odor and highest metal levels, indicating contamination from historical industrial activities continues to influence sediment and groundwater quality near these sites. Further characterization is needed to better understand contaminant mobility and impacts on the Providence River.
Absorption of radionuclides from the fukushimanuclear accident by a novel alg...trabajomuestreo
This study identified a novel algal strain, Parachlorella sp. binos, that can efficiently absorb radioactive isotopes of iodine, strontium, and cesium from its environment. Experiments showed that this alga uses light-dependent and light-independent pathways to uptake radioiodine and radiosrtrontium/cesium. High resolution analysis found that accumulated iodine was localized in the algal cytosol while strontium was distributed in the extracellular matrix. The alga was also able to uptake these radionuclides from contaminated soil and water samples from Fukushima. This algal strain shows promise for decontaminating wastewater and ecosystems exposed to radiation from nuclear accidents.
Radioactivity of Some Soil Samples from Kuba, Butura Ward, Bokkos Local Gover...ijtsrd
The activity concentration of naturally occurring radionuclide 40K, 226Ra and 232Th were measured in some soil samples from Kuba village, Bokkos Local Government Area, Plateau State, Nigeria using gamma ray spectroscopy. The soil activity ranges from 246.40± 11.32, 129.40± 6.44 and 57.92± 22 Bq.kg 1 respectively 116.70± 9.24 to 397.2± 13.32Bq.Kg 1 for 40K, 35.87± 1.02 to 88.09±1.14 Bq.kg 1 for 226Ra, and 103.60± 5.23 to 162.10± 7.11 .Kg 1 for 232Th with mean values of 246.40±11.32, 57.92±1.22 and 246.40±11.32 Bq.kg 1 respectively. The concentrations of these radionuclides are compared with the world average. The radium equivalent activity calculated from the analyzed soil samples ranges from 200.2536 to 291.9765 Bq.Kg 1 with the mean value of 261.0386 Bq.Kg 1. The mean values 40K and Radium Equivalent are low compare to the world average but the mean values for, 226Ra and 232Th are above the permissible value, therefore pose a significant threat to inhabitants or workers dealing with transportation of soil and there is no good safety index for all building made from these materials and the inhabitants due to high activity concentration of 232Th and 226Ra. Chenko G. Y. N | Mangset W. E | Terve S. J "Radioactivity of Some Soil Samples from Kuba, Butura Ward, Bokkos Local Government Area, Plateau State, Nigeria" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-6 | Issue-6 , October 2022, URL: https://www.ijtsrd.com/papers/ijtsrd52250.pdf Paper URL: https://www.ijtsrd.com/physics/other/52250/radioactivity-of-some-soil-samples-from-kuba-butura-ward-bokkos-local-government-area-plateau-state-nigeria/chenko-g-y-n
Technetium-99 is a radioactive fission product that is accumulating from nuclear industry. It is present in radioactive wastes and discharged into the environment from sources like nuclear power plants, reprocessing plants, and weapons production facilities. The document discusses the behavior and speciation of technetium in radioactive waste streams and the environment. It summarizes different approaches that have been taken to handling technetium-containing radioactive wastes, such as dilution in natural waters, underground injection, storage in tank farms, and vitrification. The mobility and migration of technetium species in waste repositories is also addressed.
This document summarizes recent progress in photocatalytic water splitting and the author's preliminary work. It discusses the significance of hydrogen energy, the mechanism of photocatalytic water splitting, and recent developments in using materials like Sm2Ti2S2O5, AgInZn7S9, and CdS for water splitting. It then describes the author's experiments studying hydrogen and oxygen evolution using CdO photocatalysts and the effects of calcination temperature and adding dopants like La2O3 and RuO2. The author's next plans involve further investigating electron acceptors for CdO, different loading species on CdO, and synthesizing doped CdO and other sulfide photocatalysts.
International Journal of Engineering and Science Invention (IJESI)inventionjournals
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
This document summarizes an experimental study on the use of unmodified lignocellulosic fibrous layer of palm tree trunk (ULFPT) as a low-cost biosorbent for removing copper (Cu2+) and zinc (Zn2+) from aqueous solutions. Batch experiments were conducted to investigate the effects of pH, initial metal ion concentration, and contact time on biosorption. Equilibrium isotherm data were fitted to Langmuir, Freundlich, Redlich-Peterson, and Temkin models to understand adsorption mechanisms. The Redlich-Peterson model provided the best fit for Cu2+ and Zn2+ biosorption. The Langmuir model also fitted the experimental data well.
This document summarizes the results of analyzing strontium isotope ratios (87Sr/86Sr) in pore water samples collected during Integrated Ocean Drilling Program Expedition 337 off Shimokita peninsula, Japan between 1289 to 2405 meters below seafloor. The ratios suggest mixing between ancient seawater and fluids derived from volcanic material alteration, as confirmed by smear slide observations showing weathered volcanic material. Ratios ranged from 0.7086 to 0.7061, with volcanic materials from the region having similar ratios to measurements at deeper levels, suggesting volcanic alteration is a source of fluids supporting deep microbial life in the area.
This document summarizes a survey of the River Etherow in Manchester, UK that analyzed water quality and pollution levels. Key findings include:
1) Organic pollution levels in the river varied between sites but were generally not high. Based on dissolved oxygen, BOD, and ammonia levels, most sites fell into the good or fair water quality categories with one site assessing as poor quality.
2) Analysis of aquatic invertebrate communities found 11 to 14 different taxa present across sites. BMWP scores ranged from 28 to 64, indicating variation in habitat quality.
3) Overall, the survey found that while organic pollution levels in the River Etherow varied between sites, the quality of water and
Trace Metals Concentration in Shallow Well Water in Enugu Metropolispaperpublications3
Abstract: This work assesses the concentration of heavy metals in Enugu Municipal well-water considering the fact that some Enugu inhabitants depend on well-water as their major source of water supply. Water from twenty four (24) different hand dug wells from six locations were investigated for Zn, Cu, Pb, Mn, Cd, and Fe using Atomic Absorption Spectroscopy (AAS). The result of the study expressed as the means and standard deviations were compared to WHO and EU standards for drinking water, and it was found that well waters from Iva-Valley and Uwani areas suffer from Cd and Mn pollution. The remaining four locations (Emene, Asata, Abakpa Nike and Achara Layout) were all free from Cd and Mn pollution. Cu, Zn, Fe and Pb concentrations were either completely absent or below world threshold limits at all the locations.
I created this poster for the 2017 Arctic Change Conference.
The poster is a preliminary research that focuses on the Geochemistry of parts of the Canadian Hudson Bay.
Keywords:
Hydrocarbons
Radioisotopes
Redox Elements
Total Organic Carbon
Principal Components Analysis
Sediments
Technetium sorption by anionexchange resins, inorganic sorbents, natural minerals and rocks. Effect of radiation. Precipitstion of sulfide. Solubility of sulfide.
Assessment of mortality and morbidity risks due to the consumption of some sa...theijes
This study assessed the mortality and morbidity risks from consuming sachet drinking waters produced in Abidjan, Côte d'Ivoire. Natural radioactivity measurements of 60 sachet water samples from 15 enterprises found concentrations of 40K, 226Ra, and 232Th ranging from 0.87-5.70 Bq/L, 0.16-0.47 Bq/L, and 0.17-0.60 Bq/L respectively. The estimated annual effective doses from ingesting these radionuclides were 45.48-113.07 μSv/y, with mortality and morbidity risks of 4.94×10-5 to 1.17×10-4 and
Release of plutonium isotopes from thefukushima daiichi nuclear power plant a...trabajomuestreo
The document summarizes studies on the release of plutonium isotopes from the Fukushima Daiichi Nuclear Power Plant accident. Key findings include:
1) Plutonium isotopes were detected in soil and litter samples northwest of the plant, indicating distribution of plutonium related to the accident. Isotopic ratios suggest reactor-derived plutonium.
2) Calculations using an ORIGEN model suggest the damaged reactors were major contributors of plutonium released. The amount released from spent fuel pools is unknown.
3) Future research should further investigate the distribution of plutonium isotopes in the environment and identify sources of plutonium release from the
Radioactive impact of fukushima accident on the iberian peninsula: evolution ...trabajomuestreo
This document analyzes the detection of radioactive materials from the Fukushima nuclear accident on the Iberian Peninsula from March 28th to April 7th, 2011. High levels of radionuclides like 131I, 132I, 132Te, 134Cs and 137Cs were measured at three monitoring stations in southwest Spain. Back-trajectory analysis of air masses showed that the radioactive plume from Fukushima reached the Iberian Peninsula. Reported radionuclide levels in places crossed by the plume, like Japan, the Pacific Ocean, and the United States, were consistent with the expected levels arriving in Huelva Province, Spain.
1) The document discusses methods for preconcentrating radionuclides from natural waters, including coprecipitation, ultrafiltration using polymers, dialysis, and membrane extraction. It finds that precipitation and ultrafiltration using polyphosphates, polyalcohols, and polyoxines are most effective for group preconcentration.
2) It also examines using these preconcentration methods to study the distribution of radionuclides like plutonium, radioruthenium, and radiocesium between colloidal fractions in bog water near Chernobyl. Most plutonium and radioruthenium were attached to colloid particles while over 90% of radioces
Monitoring of aerosol and fallout radioactivity in belgradeafter the fukushim...trabajomuestreo
1. After the Fukushima nuclear accident, a monitoring program in Belgrade analyzed samples of aerosols, fallout, food and soil for radioactive contamination.
2. Samples were collected daily from 6 air stations and 5 fallout stations around Belgrade and analyzed using gamma spectrometry.
3. The measurements found evidence of radioactive fission products 131I, 134Cs and 137Cs within 2 weeks of the accident, diminishing over time due to dispersion and radioactive decay of 131I.
Metadata on the radioactive contaminationof environmental objects on the terr...trabajomuestreo
This document provides metadata on radioactive contamination measurements taken in the USSR and Russia from 1954 to 2005. It summarizes the types of radioactive contamination measurements recorded, including beta radiation levels in the atmosphere and fallout, concentrations of radionuclides like cesium-137 and strontium-90, and tritium levels in water sources. The metadata includes details on the number and locations of observation sites, the formats and volumes of the data, and the organizations responsible for collecting and analyzing the contamination measurements.
Isotopic determination of u, pu and cs in environmental waters followingthe f...trabajomuestreo
This document summarizes the results of measuring uranium, plutonium, and cesium isotopes in water samples collected near the Fukushima Daiichi Nuclear Power Plant following its accident in 2011. Concentrations of uranium-236, plutonium-239 and -240, and cesium-137 were measured in riverine and seawater samples using accelerator mass spectrometry, inductively coupled plasma mass spectrometry, and gamma ray spectrometry. Elevated levels of cesium-137 over three orders of magnitude higher than background levels were found in river waters near the plant. Low but detectable levels of uranium-236 and plutonium isotopes were also observed, with pluton
Fukushima fallout in northwest german environmental mediatrabajomuestreo
Traces of radioactive isotopes from the Fukushima nuclear accident, including 131I, 134Cs and 137Cs, were detected in environmental samples collected in Northwest Germany between March and May 2011. Measured concentrations of 131I in rainwater samples agreed with estimated deposition values based on reported air concentrations and rainfall amounts. 137Cs concentrations were higher and were attributed mostly to previous nuclear testing and Chernobyl fallout. The 134Cs/137Cs ratio allowed discrimination of recent versus older 137Cs. While 136Cs was below detection limits, the measurements provide evidence of transoceanic transport of Fukushima-derived radionuclides to Northwest Germany.
Evidence of the radioactive fallout in the center of asia (russia)following t...trabajomuestreo
The document summarizes evidence of radioactive fallout detected in environmental samples collected in Krasnoyarsk, Russia following the Fukushima nuclear accident in Japan. Samples of melted snow, rainwater, pine needles and air filters collected between April and May 2011 contained radioactive isotopes like iodine-131, cesium-134 and cesium-137 released from Fukushima. The detection of these isotopes in central Asia provides evidence of the long-range transport of radioactive contamination from Fukushima across the Pacific and Eurasia, similar to fallout patterns observed after Chernobyl. Levels of iodine-131 and ratios of cesium isotopes in Russian samples were comparable to those measured in Greece, suggesting linkage
Estimation of the adriatic sea water turnover time using falloutsr as aradiac...trabajomuestreo
1. The document analyzes measurements of 90Sr activity concentrations in Adriatic Sea water from 1963-2003 at multiple locations along the Croatian coast.
2. A mathematical model was developed using 90Sr data from sea water and fallout samples to estimate the mean residence time of 90Sr in the Adriatic Sea.
3. By fitting the experimental 90Sr data to the theoretical model, the mean residence time of 90Sr in the Adriatic Sea was estimated to be approximately 3.4 ± 0.4 years. This value reflects the upper limit for the turnover time of Adriatic Sea water.
Different methods for tritium determination in surface water by lsctrabajomuestreo
This document compares three methods for determining tritium levels in surface water samples: electrolytic enrichment, direct measurement without enrichment, and using a Sample Oxidizer. Tritium is a radioactive isotope of hydrogen that can replace water in living cells. The three methods were tested on rainfall and stream water samples from Serbia. Electrolytic enrichment concentrates tritium in water samples to make detection easier. Direct measurement analyzes untreated water. The Sample Oxidizer method oxidizes organic matter before analysis. All prepared samples were measured by liquid scintillation counting, and results from the three methods showed good agreement. Detection limits for each method were determined. The methods provide comparable results for environmental monitoring of tritium in water.
Source and distribution of dissolved radium in the bega riverestuary, southea...trabajomuestreo
This document describes a study of radium isotopes in the Bega River estuary in Australia. Measurements of radium-224, radium-223, radium-226, and radium-228 were made in surface water and sediment porewater to understand the source and distribution of dissolved radium in the estuary. The results show that bottom sediments are a major source of radium to the estuary surface waters, with radium accumulating in porewater and mixing into surface waters via tidal exchange. A model was applied to estimate the daily flux of porewater crossing the sediment-water interface, about 15% of the total estuary volume.
Source and distribution of dissolved radium in the bega riverestuary, southea...
Radioactive contamination of aquatic ecosystemsfollowing the chernobyl accident
1. J. Environ. Radioactivity. Vol. 27 No. 3, pp. 207-219, 1995
Copyright 0 1995Elsevier Science Limited
Printed in Ireland. All rights reserved
0265-93 I X/95 $9.50 + 0.00
ELSEVIER 0265-931 X(94)00042-5
Radioactive Contamination of Aquatic Ecosystems
Following the Chernobyl Accident
I. I. Kryshev
Institute of Experimental Meteorology, SPA ‘Typhoon’, 82 Lenin Avenue, Obninsk,
Kaluga Region, 249020 Russia
(Received 9 February 1993; accepted 25 July 1994)
ABSTRACT
The dynamics of radioactive contamination of aquatic ecosystems (1986
1990) is considered on the basis of observational data in the near and
distant zones of the Chernobylfallout (the Chernobyl Nuclear Power Plant
(CNPP) cooling pond, the Pripyat River, the Dnieper reservoirs, and the
Kopor inlet of the Gulf of Finland). Radionuclide accumulation in aquatic
biota is analyzed.
The results obtained indicate that the radioecological conditions in the
water bodies under investigation were in a state of non-equilibrium over a
long period of time following the Chernobyl accident. Reduction in the
‘37Cs concentration proceeded slowly in most of the aquatic ecosystems.
The effect of trophic levels which consisted of increased accumulation of
radiocaesium by predatory fish was observed in various parts of the
contaminated area.
INTRODUCTION
The aquatic environment plays a special role in evaluation of the possible
consequences of the nuclear accident for people as well as for ecosystems.
The radioactive substances enter water bodies not only as a result of
atmospheric fallout and direct discharge but also due to radionuclide
washoff from the water-catchment areas. In contaminated water bodies,
radionuclides are quickly redistributed and accumulated in such compo-
207
2. 208 I. I. Kryshev
nents as bottom sediments, benthos, aquatic plants, and fish. This is of
particular concern from the viewpoint of radiation exposure of aquatic
organisms and humans connected by food-chains within the hydrosphere.
Monitoring data on radioactive contamination of surface water and sedi-
ments following the Chernobyl NPP accident have been reported (Izrael et
al., 1990; Vakulovsky et al., 1990).
This paper emphasizes the accumulation of radionuclides in aquatic
biota based on radioactive contamination of aquatic ecosystems in various
areas of the emergency zone that differed significantly in contamination
levels (Fig. 1): in the CNPP cooling pond, rivers of the Dnieper catchment
area, the Dnieper reservoirs, etc. (Kryshev, 1991, 1992; Kryshev et al.,
1993; Kuzmenko et al., 1991).
EXPERIMENTAL
Samples of water, bottom sediments and aquatic biota were taken from
the Chernobyl cooling pond, the Pripyat River, the Dnieper cascade
reservoirs and others. Radionuclide contents were determined by using the
Dniepropetrovsk
Fig. 1. The Dnieper reservoir system.
3. Radiouctive contamination of aquatic ecos~stt~m.s,follo,c~ing Chernoh~~l 209
radiochemical, radiometric or gamma-spectrometric method. 90Sr was
determined through its daughter, 9oY. Gamma-spectrometric measure-
ments were carried out using the AI-1024 or AI-4096 gamma analyzer
with a semiconductor detector.
RADIOACTIVE CONTAMINATION OF THE CHERNOBYL
COOLING POND ECOSYSTEM
The CNPP cooling pond is the most contaminated water body in the
Chernobyl emergency zone (Fig. 2). Therefore it can serve as a model to
be used for estimation and forecasting of potential consequences of
radioactive contamination of aquatic systems.
The CNPP cooling pond located to the southeast of the NPP site was
formed by cutting off part of the Pripyat River plain with a dike. The area
of the cooling pond is 22 km2, its average depth is 6.6 m, and volume is 0.15
km”. The cooling pond is characterized by moderate values of mineraliza-
tion (260-430 mg/l). Transparency of water in autumn and spring is 1.2-1.3 m
and in summer it is 0.6 m. The content of suspended matter ranges from 10
to 30 mg/l. The distribution of nutrients across the water body is relatively
uniform. The ranges of time dependent parameters of hydrochemical
regime are: ammonia nitrogen, 0.15-3.46 mg N/l; nitrites, 0.0 1-O.17 mg N/l;
nitrates, 0.1-2.3 mg N/l; organic nitrogen, 0.01-3.28 mg N/l; phosphates,
0.01-0.51 mg P/l; organic phosphorus, O@lO.55 mg P/l; iron, 0.01-0.82
mg/l; silicon, 0.1-5.4 mg/l; oxygen, -2612.2 mg/l; pH, 7.487 (Kaftan-
nikova et al., 1987). According to monitoring data from May 1986, the
radioactivity in the cooling pond water was mainly characterized by ‘j’1
and other short-lived radionuclides (Table 1). In the following months
water activity decreased considerably as a result of radioactive decay and
radionuclide deposition to bottom sediments. Since then the radioisotopes
of caesium made a principal contribution to water radioactivity. The
concentration of 90Sr in the cooling pond in August 1986 did not exceed 2-
3% of the ‘37Cs concentration.
The radionuclide distribution in bottom sediments of the cooling pond
was characterized by a pronounced nonuniformity. Very high radio-
nuclide concentrations were registered in silts that comprised 27% of the
reservoir bottom area. The maximum total activity concentration levels in
silts were 8-10 MBq/kg, fresh weight. Other radionuclides made the
following contributions to the total activity of bottom sediments: 95Zr and
95Nb, 54-70%; ‘44Ce, 7-20%; ‘06Ru, 4%; ‘37Cs, 2-5%; 134Cs l-2%. The
concentration of 90Sr in bottom sediments in 1986 was 60 kBq/kg, or
about 35% of ‘37Cs. In 1987-1988 the total activity in bottom sediments
4. 210 I. I. Kryshev
*,
0 1
L-l---l
2
km 1
Fig. 2. Scheme of the Chernobyl NPP cooling pond (with isolines of contamination with
13’Cs, MBq/m*).
decreased as a result of radioactive decay. The contribution of long-lived
*37Cs to the total activity amounted to 20-60% in 1988, and its concen-
tration in silts was 0.4 MBq/kg on average.
Radioactive contamination of aquatic plants (algae, mainly Cladophora
glomerata Kuetz) in the cooling pond was characterized by different
radionuclides. According to the average data, 95Zr and 95Nb (35%) lUCe
(32%) ‘06Ru (4%), ‘37Cs (2-5%) and ‘34Cs (l-2%) contributed primarily
to the total activity of aquatic plants in summer and autumn of 1986. The
5. Radioactive contamination of aquatic ecosystems following Chernobyl 211
TABLE 1
The Estimated Activity of Water and Sediments in the Chernobyl Cooling Pond (30 May
1986)
Radionuclide Water Sediments
Activity Total amount Activity Total amount
(Bqll) ( TBq) (MBqim’1 ( TBq)
40 * 21 6+4 2.3 f 1.0 50 f 20
330 * 200 50 f 30 54 f 20 1200 zt 450
410 f 210 70+40 50f 18 1100zt400
270 f 100 40f 15 32f 16 700 f 360
13oi70 20f 10 lOf5 220 f 100
1700 f 400 250 f 60 1.4 f 0.4 30f 10
200 k 100 30f 15 2.7 f 1.8 60 f 40
400 f 200 60 zt 30 5.0 f 2.3 llOf50
800 f 500 120 It 70 18f6 400 f 140
530 f 270 80 f 40 13f6 280 f 120
330 f. 200 50 f 30 30f 14 640 f 280
200 * 130 30 f 20 40 zk 20 860 f 400
average contribution of 90Sr amounted to about 2%. The maximum
observed levels of activity concentration in aquatic plants in 1986 were
2.4 MBq/kg, fresh weight.
In 19861987 the radioactive contamination of molluscs in the cooling
pond was mainly governed by 90Sr, ‘44Ce, ‘06Ru, 137Csand ‘34Cs. In 1986
the maximum total activity concentration in molluscs was O-4 MBq/kg,
with the concentration of 90Sr being 5.0 x lo4 Bq/kg, and lUCe being
1.8 x 10’ Bq/kg. The mean concentration of ‘37Cs in molluscs was about
2.6 x lo4 Bq/kg in 1986 and 1.9 x lo4 Bq/kg in 1987.
The estimated average concentrations of long-lived ‘37Cs and 90Sr in
ecosystem components of the cooling pond are presented in Tables 2 and 3.
For most fish species, radioisotopes of caesium occurred in muscle
tissue (Table 4). In 19861987 the concentration of caesium radioisotopes
in gills, scale, skin and fins decreased as compared to muscles. For exam-
ple, for a pike-perch of 60&700 g, the ratio of the ‘37Cs content in
muscles, gills and skin was: 1-O: 0.8 : 1.0 in 1987; 1.0 : 0.5 : O-3 in 1988
and 1-O: 0.4 : 0.2 in 1990. Fatty tissues were contaminated by caesium
radioisotopes to a lesser extent. Radionuclides such as lWCe, lo6Ru, 95Zr
and 95Nb were mainly contained in the GI tract, gills and skin and were
rarely detected in fish muscles. Analysis of the dynamics of the 137Cs
content in muscles of various species of fish shows the difference in the
processes of radiocaesium accumulation for ‘predatory’ and ‘non-preda-
tory’ species (Table 4). For ‘non-predatory’ species (carp, silver carp,
6. 212 I. I. Kryshev
TABLE 2
The Estimated “‘Cs Content in the Ecosystem Components of the Chernobyl NPP Cool-
ing Pond (1986-1990)
Year Water (Bqll) Bottom sediments Algae MONUSCS
IkBq/kgj:w) CkBq1kg.f.w.) (kBqlkgf1w.j
1986 210f80 170 i 100 90 i 40 26i 7
(I 700) (440) (160) (36)
1987 60 f- 40 60 i 30 16f 10
(700) (170) (30)
1988 19f7 160f90 25f 10
(240) (460) (40)
1990 14&6 140 f 100 19f8
(23) (380) (40)
Presented are the average annual concentrations (June-December 1986). Figures in
brackets are the maximum observed “‘Cs concentrations in the ecosystem components.
TABLE 3
The Estimated 90Sr Content in the Ecosystem Components of the Chernobyl NPP Cooling
Pond (July-December 1986), kBq/kg Fresh Weight
Ecosystem components ‘(‘Sr concentration
Water 0.02 l 0.013 (0.04)
Bottom sediments 6Oi25 (140)
Algae 15f9 (40)
Molluscs 40f 10 (60)
Fish 2.0 f 1.2 (4)
Presented are the average concentrations. Figures in brackets are the maximum observed
concentrations of 90Sr in the ecosystem components.
silver bream) the highest contamination by radiocaesium was reported in
1986. For ‘predatory’ species (pike, pike-perch, perch) the maximum levels
of radiocaesium were observed in 1987-1988. It should be noted that the
maximum ‘s7Cs contamination level for predatory species exceeded that
of nonpredatory ones by 3-10 times, i.e. the effect of trophic levels in
radiocaesium accumulation was clearly reflected.
According to monitoring data of 1986, the 90Sr content in fish was about 2
kBq/kg fresh weight on average, or about 1% of the ‘37Cs content (Table 3).
RADIOACTIVE CONTAMINATION OF RIVER ECOSYSTEMS
Radioactive contamination of river ecosystems was noted early after
the accident: late April-early May 1986. The total activity of water in
7. Rudioactive contamination of aquatic ecosystems following Chernobyl 213
TABLE 4
The Average Values of the 13’Cs Content in Muscles of Various Fish Species in the Cher-
nobyl NPP Cooling Pond (19861990), kBq/kg Fresh Weight
Year Carp Silver bream Silver carp Perch Pike-perch
1986 loo+40 110*40 140*30 180+40 30f I3
(260) (240) (180) (220) (50)
1987 50 It 30 100 i 50 100 f 50 200 f 100 170*90
(320) (280) (240) (410) (420)
1988 40f 14 401t 18 40f 18 160 f 100 1501t80
(60) (100) (100) (360) (360)
1989 25 & 6 403 13 82% 10
(40) (90) (100)
1990 15&5 8f3 12f8 60 + 20 80 i 40
(25) (15) (70) (90) (170)
Presented are the average annual concentrations. Figures in brackets are the maximum
observed ‘37Cs concentrations in fish muscles.
this period amounted to 10 kBq/l in the Pripyat River (the Chernobyl
region), 5 kBq/l in the Uzh River and 4 kBq/l in the Dnieper River.
In this period the short-lived nuclides, primarily 1311, were of princi-
pal radio-ecological importance. The dynamics of the ‘st1 content in
water and fish of the Kiev reservoir in May-June 1986 is presented in
Fig. 3.
In the same period, such radionuclides as 13*Te, 14’Ba, 14’La, 99Mo,
lo3Ru, ‘44Ce, 14’Ce, 95Zr, 95Nb, 239Np, 137Cs, 134Cs, etc., were also detec-
ted. The activity of short-lived radionuclides exceeded that of long-lived
caesium radioisotopes by an order of magnitude (Table 5). The activity of
90Sr in the Pripyat River on 1 May 1986 was 30 f 20 Bq/l. The ratio of
89Sr/90Sr ranged from 7 to 14. From the end of May to June, the 90Sr
content in the Pripyat River was l-2 Bq/l. The maximum concentration of
239,240Pu observed in the Pripyat River water in the first few days of May
(0.4 Bq/l) fell to 7.4 mBq/l by August 1986 (Izrael et al., 1990). The
activity of suspended matter contaminated by the 13*Te, 14’Ba, 99M~, 95Zr,
95Nb, 144ce, 141c,, 239
Np exceeded that of the water fraction. The activity
of water decreased significantly as the short-lived nuclides decayed and
deposited with particles into bottom sediments. Even in June 1986 it had
decreased by 100 times as compared to the early period of emergency
contamination and was mainly characterized by 134Cs, ‘37Cs and 90Sr.
95Zr, 95Nb, ‘44Ce, 14’Ce, lo3Ru and ‘06Ru settled on the bottom with
particles and made a principal contribution to the contamination of
bottom sediments in May 1986 (Table 6). The contribution of caesium
radioisotopes to the total activity in bottom sediments of the Pripyat
8. 214 1. I. Kryshev
4;20 5/l 5/10 5/20 5130 WlO 6120
Fig. 3. The 13r1content in water and fish muscles of the Kiev reservoir in May-June 1986.
TABLE 5
The Radionuclide Content in River Waters in the Early Period After the Accident (I May
1986), Bq/l
Radionuclide Pripyat River (Chernobyl) Kiev Reservoir (Lyutezh)
Water Suspended matter Water Suspended matter
131*
2100f600 100 f 30 14ozt40 80 f 25
132
I 750 f 300 240 f 100 60 k 20 220 k 80
14*Ba 1400*400 18Oi70 240 i 100
99Mo 670 It 200 70 f 25 200 f 70
lo3Ru 550 f 200 230 f 90 l5f6 310 f 120
“Ye 380 f 150 l60f60 200 f 80
14’Ce 400 f 140 260 f 100 250 f 80
95Zr 400 f 150 270 f 100 7*4 250 f 100
“Nb 420 i 160 250 f 100 614 230 f 90
239N~ 360 50
’34cs 130f50 lOf6 4f2 lOzt6
I37cs 250 f 100 20f 10 lOf5 20f 10
“Sr (water and 30 f 20 5f2
suspended matter)
9. Radioactive contamination of aquatic ecosystems,fofiowing Chernobyl 215
TABLE 6
The Estimated Content of Radionuclides in the Bottom Sediments of the Dnieper Reser-
voirs and the Pripyat river (kBq/m2)
Radionucfide Pripyat River (mouth) Kiev reservoir Kanev reservoir
95Zr 6000 f 3800 190 f 80 120 It 50
y5Nb 800 + 500 200 zt 80 170 f 70
‘03RLl 3 600 l 2000 90 f 50 100 f 60
131
1 800 III 500 2oxt 12 30 f 20
‘34cs 900 f 500 6f3 8f4
137Cs
1500 f 800 12 f 5 16 f 7
14’Ba 2400 zt 1700 30 f 20 60 f 38
14’La 2600 it 1800 70 f 46 85 f 50
14’Ce 4500 + 1600 100 f 40 100 * 30
‘44Ce 6200 f 2400 120 f 50 120 f 40
River, Dnieper River, Kiev and Kanev reservoirs in that period was about
2-7%. For other reservoirs (Kremenchug, Dneprodzerzhinsk, Kakhovka)
located downstream in the Dnieper River, the contribution of caesium
radioisotopes to the total activity of bottom sediments was somewhat
higher, i.e. lO--30%. Distribution of radionuclides in bottom sediments
was characterized by notable inhomogeneity (‘spottiness’). Very high
levels of radioactive contamination were registered in the upper layer of
silts (Vakulovsky et al., 1990; Kryshev, 1992).
The long-term radioecological consequences of the Chernobyl acci-
dent are largely estimated from contamination of the affected territory
by long-lived radionuclides ( ‘37Cs, ‘34Cs, 90Sr). As noted above, in the
first period following the accident the contribution of long-lived radio-
nuclides in the rivers of the Dnieper catchment area and its reservoirs
amounted to 10% of the total activity. But as short-lived radionuclides
decayed, the contribution of caesium and strontium radioisotopes to
the exposure dose of organisms increased and then prevailed. Tables 7
and 8 show estimates of the annual mean content of ‘37Cs and 90Sr in
water, molluscs and fish based on observational data for 1986-1989
(Pankov, 1990; Volkova, 1990; Kryshev, 1992; Kryshev et al., 1993).
Highest levels of contamination by ‘37Cs occurred for all ecosystem
components of the Kiev reservoir. The Kanev reservoir, which is
downstream in the Dnieper River showed concentrations of ‘37Cs in
fish and molluscs 3-4 times lower than those in the Kiev reservoir.
Downstream along the cascade of reservoirs (the Kremenchug reservoir
and others), the ‘37Cs levels were increasingly lower. Mean levels of 90Sr
concentration in water for the Kiev reservoir in 1987-1989 practically
did not differ from the annual mean concentration in 1986. For
10. 216 I. I. Kryshev
TABLE 7
The Estimated 13’Cs Content in the Ecosystem Components of the Dnieper Reservoirs
Yeur Water (Bqllj Mollusc Dreissena Fish (Bq1kgf.w.j
bugensis (Bq1kg.f.w.)
Bream Pike-perch
Kiev reservoir
1986 2.0 * 1.0 670 f 160 960 f 400 220 f 100
1987 o-5 i 0.2 110*30 480 f 160 590 + 170
1988 0.4 + 0.1 70 x?T
20 440 zt 100 1 040 f 360
1989 0.4hO.l 70% 16 370 i 80 440 i 150
Kanev reservoir
1986 0.1 f 0.04 100&40 190 f 100 60 i 20
1987 0.1 f 0.03 100 % 30 90 f 20 280 i! 60
1988 0.2 i 0.05 5oi IO 30f 14 170*50
1989 0.2 f 0.04 30 f 4 26xt IO 80f 16
Kremenchug reservoir
1986 0.05 + 0.02 lOf4 -.
1987 0.03 zt 0.01 30 f 8 180&50 260 f 80
1988 0.04 i 0.01 40 It 5 23 f 4 3Ozt 16
i989 0.05 i 0.0 1 3066 IO&6 30 * 7
The data presented in Tables 7 and 8 are taken from the following publications: water
(Kryshev, 1992); biota, 1986 (Ibid.); molluscs, 1987-1989 (Pankov, 1990); fish, 1987-1989
(Volkova, 1990).
molluscs accumulating 90Sr in their shells, the contamination by 90Sr
significantly exceeded that of ‘37Cs.
RADIOACTIVE CONTAMINATION OF SEA ECOSYSTEMS
The Chernobyl accident resulted in radioactive contamination of some
regions distant from the Chernobyl site. Some coastal regions of the Baltic
Sea, in particular, were affected by the CNPP radioactive release.
TABLE 8
The Estimated “Sr Content in the Ecosystem Components of the Kiev Reservoir (1986
1989)
Year Water (Bqll) Mollusc Dreissena Fish (Bq/kgf.w.)
bugensis (Bq1kgf.w.)
Bream Pike-perch
1986 0.85 f 0.30 1000 f 400 60 f 30
1987 0.56 xt 0.18 700 f 200 16f3 10+4
1988 0.78 f 0.23 1 100 f 300 30 * 5 70 f 20
1989 0.37 f 0.10 1 200 f 300 20 f 6 40* 15
11. Radioactive contamination qf‘aquatic ecos~stems,fi)lloM,ing Chernobyl 217
According to the monitoring data from Sosnovy Bor (Leningrad region),
located on the coast of the Gulf of Finland, atmospheric fallout and
radionuclide washoff from the catchment areas were responsible for
radioactive contamination of sea and river ecosystems (Kryshev, 1991,
1992). By 1 May 1986 the concentration of ‘j’1 in the river water in
Sosnovy Bor amounted to 130-150 Bq/l. The concentration of “‘I in fish
muscles in the coastal waters of the Gulf of Finland from 2 May to 22
May 1986 was 40-50 Bq/kg. After the decay of iodine and other short-
lived radionuclides, radioisotopes of caesium were of particular radio-
ecological concern for aquatic biota. Table 9 shows the dynamics of “‘Cs
content in aquatic ecosystem components of the Kopor inlet of the Gulf of
Finland. From the monitoring data obtained in 1989-1990 the concen-
tration of ‘37Cs in components of aquatic ecosystems exceed the back-
ground levels of contamination for 1985. A distinct effect of trophic levels
on radiocaesium accumulation was observed for predatory species of fish.
For example, the concentration of ‘37Cs in perch was growing after the
Chernobyl accident and since 1987, it is 2-5 times higher than that of
sprat.
CONCLUSION
The studies of radioactive contamination of aquatic ecosystems carried
out in the areas affected by the Chernobyl contamination in 1986-1990
show:
(i) One of the most contaminated water bodies in the zone of the
Chernobyl accident is the cooling pond of the Chernobyl NPP.
TABLE 9
The “‘Cs Content in the Ecosystem Components of the Kopor Inlet, the Gulf of Finland
(1985-1990)
Year Sea water Bottom sedi- Algae Perch Sprat
fmBqll) ments (Bqjkg) (Bqlkg) (Bq1kg.f.w.i (Bqlkg.1:rv.j
1985 10&3 I .2 f 0.6 3.9 l 1.4 3.5 f 1.0 1.4 It 0.5
1986 1 050 i 500 40 f 20 175 + 120 22 + 8 54 * 30
(185)* (2 770)*
1987 230 f 110 19f4 30f 12 120f40 60 f 20
1988 120f40 lOzt.5 30% 10 130f40 25 f 8
1989 56f II IO-f5 24 zt 8 120 f 30 26i IO
1990 50+ 10 5It-3 141t6 116f30 36i IO
*The maximum observed concentration.
12. 218 I. I. Kryshev
This water body could be used as a model for assessing extreme
consequences of an accident for aquatic ecosystems.,
(ii) As a result of the processes of radioactive decay and settling of
radionuclides on the bottom of water bodies, the radioactive
contamination was notably reduced for most components of
aquatic ecosystems beyond the nearest zone affected by the Cher-
nobyl accident. However, in future the reduction of radioactive
contamination levels will, most likely, go more slowly since the
radiation situation in water bodies at the present time is largely
determined by long-lived radionuclides of 13’Cs and 90Sr. For most
of the surveyed water bodies the effect of trophic levels was clearly
seen in radiocaesium uptake by predatory fish.
The results of this investigation indicate that the processes involved in
the formation of the current radioecological situation in water bodies
caused non-equilibrium for a long period after the Chernobyl accident.
Further studies on radioecological processes in the Chernobyl contami-
nated areas should, probably, focus on the role of aquatic biota in
biogenic migration and possible transformation of migration character-
istics of long-lived radionuclides. Serious attention should also be given to
the problems of radionuclide migration and accumulation in trophic
chains of aquatic ecosystems, assessment and prediction of long-term
irradiation dose for man through the aquatic food chain.
ACKNOWLEDGMENT
The author would like to express his gratitude to Dr William L. Temple-
ton for his suggestions, discussions and valuable comments.
REFERENCES
Izrael, Yu. A., Vakulovsky, S. M., Vetrov, V. A., Petrov, V. N., Rovinsky, F. Ja.
& Stukin, E. D. (1990). Chernobyl: Radioactive Contamination of the Envir-
onment. Gidrometeoizdat, Leningrad, pp. l-296 (in Russian).
Kaftannikova, 0. G., Protasov, A. A., Sergeeva, 0. A., Kahnichenko, R. A.,
Vinogradskaya, T. A., Lenchina, L. G., Kosheleva, S. I., Novikov, B. I.,
Afanasiev, S. A., Sinitsina, 0. O., Movchan, N. B. & Pankov, N. G. (1987).
The Ecology of NPP’s Cooling Pond. Ukraine Academy of Sciences, Kiev, pp.
1-97 (in Russian).
Kryshev, I. I. (1991). Radioactive contamination and radioecological conse-
quences of the Chernobyl accident. In Nuclear Accidents and the Future of
Energy, Proc. Int. Conf., Paris, 15-17 April 1991. FNS, Paris, France
pp. 167-78.
13. Radioactive contamination of aquatic ecosystems fotIowing Chernobyl 219
Kryshev, I. I. (ed.) (1992). Radioecological Consequences of the Chernobyl Acci-
dent, Nuclear Society, Moscow, Russia, pp. l-142.
Kryshev, I. I., Ryabov, I. N. & Sazykina, T. G. (1993). Using a Bank of Preda-
tory Fish Samples for Bioindication of Radioactive Contamination of
Aquatic Food Chains in the Area Affected by the Chernobyl Accident. Sci.
Total Environ,, 1391140, 279-85.
Kuzmenko, M. I., Pankov, I. V., Volkova, E. N. & Shirokaya, Z. 0. (1991).
Artificial radionuclides in aquatic biota of major European rivers. In Seminar
on Comparative Assessment of the Environmental Impact of Radionuclides
Released during Three Major Nuclear Accidents: Kyshtym, Windscale, Cher-
nobyl. Proc. Seminar, Luxembourg, I-5 October 1990, Vol 2. CEC, EUR
13574, Brussels, Belgium, pp. 665-77.
Pankov, I. V. (1990). Fission Fragments of Uranium in Molluscs in the Dnieper
Reservoirs after the Chernobyl Accident. Ukraine Academy of Sciences, Kiev,
pp. 1-28 (in Russian).
Vakulovsky, S. M., Voitsekhovich, 0. V., Katrich, I. Yu., Medinets, V. I., Niki-
tin, A. I. & Chumichev, V. B. (1990). Radioactive contamination of river
systems in the area affected by releases from the Chernobyl nuclear power
plant accident. In Environmental Contamination Following a Major Nuclear
Accident, Proc. Int. Symp., Vienna, 16-20 October 1989, Vol 1. IAEA-SM-
306/l 15, IAEA, Vienna, Austria, pp. 23146.
Volkova, E. N. (1990). Radioactive Contamination of Fish Fauna in the Dnieper
Reservoirs after the Chernobyl Accident. Ukraine Academy of Sciences, Kiev,
pp, l-25 (in Russian).