Formation of chlorinated breakdown products during degradation of sunscreen a...Maciej Przybyłek
In this study, a new degradation path of sunscreen active ingredient, 2-ethylhexyl-4-methoxycinnamate (EHMC) and 4-methoxycinnamic acid (MCA) in the presence of sodium hypochlorite (NaOCl), was discussed. The reaction products were detected using gas chromatography-mass spectrometry (GC-MS). Since HOCl treatment leads to more polar products than EHMC, application of polar extracting agents, dichloromethane and ethyl acetate/n-hexane mixture, gave better results in terms of chlorinated breakdown products identification than n-hexane. Reaction of EHMC with HOCl lead to the formation of C=C bridge cleavage products such as 2-ethylhexyl chloroacetate, 1-chloro-4-methoxybenzene, 1,3-dichloro-2-methoxybenzene, and 3-chloro-4-methoxybenzaldehyde. High reactivity of C=C bond attached to benzene ring is also characteristic for MCA, since it can be converted in the presence of HOCl to 2,4-dichlorophenole, 2,6-dichloro-1,4-benzoquinone, 1,3-dichloro-2-methoxybenzene, 1,2,4-trichloro-3-methoxybenzene, 2,4,6-trichlorophenole, and 3,5-dichloro-2-hydroxyacetophenone. Surprisingly, in case of EHMC/HOCl/UV, much less breakdown products were formed compared to non-UV radiation treatment. In order to describe the nature of EHMC and MCA degradation, local reactivity analysis based on the density functional theory (DFT) was performed. Fukui function values showed that electrophilic attack of HOCl to the C=C bridge in EHMC and MCA is highly favorable (even more preferable than phenyl ring chlorination). This suggests that HOCl electrophilic addition is probably the initial step of EHMC degradation.
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
International Journal of Computational Engineering Research(IJCER)ijceronline
International Journal of Computational Engineering Research(IJCER) is an intentional online Journal in English monthly publishing journal. This Journal publish original research work that contributes significantly to further the scientific knowledge in engineering and Technology.
Catalytic Degradation of 4-Nitrophenol Using Gamma Irradiated PVA/Ag Nanocomp...IJERA Editor
In this work, PVA/Ag nanocomposites were prepared by adding different volumes of AgNO3 to PVA solution. PVA/Ag nanocomposites used as a catalyst for the degradation of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). The responsive catalyst is easily synthesized, environmentally compatible, cost-effective and can be easily recovered by handling from the aqueous solution. The shape and particle size distribution were studied using Transmission Electron Microscope (TEM). The X-Ray diffraction (XRD) and UV-visible Absorption Spectra of Gamma-irradiated PVA/AgNO3 Films were studied.
Formation of chlorinated breakdown products during degradation of sunscreen a...Maciej Przybyłek
In this study, a new degradation path of sunscreen active ingredient, 2-ethylhexyl-4-methoxycinnamate (EHMC) and 4-methoxycinnamic acid (MCA) in the presence of sodium hypochlorite (NaOCl), was discussed. The reaction products were detected using gas chromatography-mass spectrometry (GC-MS). Since HOCl treatment leads to more polar products than EHMC, application of polar extracting agents, dichloromethane and ethyl acetate/n-hexane mixture, gave better results in terms of chlorinated breakdown products identification than n-hexane. Reaction of EHMC with HOCl lead to the formation of C=C bridge cleavage products such as 2-ethylhexyl chloroacetate, 1-chloro-4-methoxybenzene, 1,3-dichloro-2-methoxybenzene, and 3-chloro-4-methoxybenzaldehyde. High reactivity of C=C bond attached to benzene ring is also characteristic for MCA, since it can be converted in the presence of HOCl to 2,4-dichlorophenole, 2,6-dichloro-1,4-benzoquinone, 1,3-dichloro-2-methoxybenzene, 1,2,4-trichloro-3-methoxybenzene, 2,4,6-trichlorophenole, and 3,5-dichloro-2-hydroxyacetophenone. Surprisingly, in case of EHMC/HOCl/UV, much less breakdown products were formed compared to non-UV radiation treatment. In order to describe the nature of EHMC and MCA degradation, local reactivity analysis based on the density functional theory (DFT) was performed. Fukui function values showed that electrophilic attack of HOCl to the C=C bridge in EHMC and MCA is highly favorable (even more preferable than phenyl ring chlorination). This suggests that HOCl electrophilic addition is probably the initial step of EHMC degradation.
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
International Journal of Computational Engineering Research(IJCER)ijceronline
International Journal of Computational Engineering Research(IJCER) is an intentional online Journal in English monthly publishing journal. This Journal publish original research work that contributes significantly to further the scientific knowledge in engineering and Technology.
Catalytic Degradation of 4-Nitrophenol Using Gamma Irradiated PVA/Ag Nanocomp...IJERA Editor
In this work, PVA/Ag nanocomposites were prepared by adding different volumes of AgNO3 to PVA solution. PVA/Ag nanocomposites used as a catalyst for the degradation of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). The responsive catalyst is easily synthesized, environmentally compatible, cost-effective and can be easily recovered by handling from the aqueous solution. The shape and particle size distribution were studied using Transmission Electron Microscope (TEM). The X-Ray diffraction (XRD) and UV-visible Absorption Spectra of Gamma-irradiated PVA/AgNO3 Films were studied.
The radiolytic mineralization of 2-mercaptobenzothiazole, an emerging contami...IRJESJOURNAL
Abstract:The ability of high-energy ionizing radiation has been demonstrated for environmental remediation processing. γ-rayswere applied to treat a solution of 2-mercaptobenzothiazole (2-MBT). 2-MBT (125 µM) was decomposed and mineralized by the γ-radiation. The absorbed doses for 50 and 90% 2-MBT degradation were 0.170 and 0.650 kGy, respectively. Organic by-products were almost fully mineralized when high-absorbed doses in the range of 5-60 kGy were applied. Sulfate radicals (SO4 ●– ) produced through the rapid reaction of persulfate ions (S2O8 2– ) with hydrated electrons(eaq − ; keaq − /S2O8 2– = 1.1 × 1010 M −1 .s−1 ) had a significant effect on the 2-MBT mineralization yield. Because of 2-MBT decomposition,sulfate ions (SO4 2− ) were formed, and thepH and dissolved oxygen concentration were decreased. The degradation efficiency decreased when HCO3 –was added to the 2- MBT solution. No significant effects of NO3 – and Cl– ions on 2-MBT radiolytic eliminationwere observed
The Influence of Vermiculite on the Uptake of Silver Nanoparticles in a Terre...Agriculture Journal IJOEAR
— The uptake of silver from silver nanoparticles in soil was investigated in the presence of increasing concentrations of Vermiculite, typical 2:1 clay. Two insect species, Acheta domesticus and Tenebrio molitor, and two plant species, Helianthus annuus and Sorghum vulgare, were exposed to silver nanoparticles in the presence of increasing concentrations of Vermiculite in soil. Silver nanoparticles were characterized using techniques including transmission electron microscopy, dynamic light scattering, and powder X-ray diffraction. The levels of silver in test species exposed to silver nanoparticles were measured using an inductively coupled plasma-optical emission spectrometer. An increase in the cation exchange capacity of soil was observed with the increase in the concentration of vermiculite in soil. The results suggested a decrease in the uptake of silver from silver nanoparticles in soil by Acheta domesticus as a function of increasing concentrations of Vermiculite in soil. No apparent trend was observed in the remaining species. Both plant species were found to accumulate silver in their roots. The translocation of silver to stems and leaves was observed in the case of Helianthus annuus. Results from this study suggest that the presence of Vermiculite in soil could possibly decrease the uptake of silver from silver nanoparticles.
Isolation and Characterization of Nickel Tolerant Bacterial Strains from Elec...Agriculture Journal IJOEAR
Abstract— In the present study, an attempt was made to isolate and characterize nickel tolerant bacterial strains from the electroplating effluent contaminated soil. The effluent sample was collected at the direct outlet of electroplating industry and analyzed for physico-chemical characteristics such as pH (6.5), temperature (33), electrical conductivity (15.1 ms/cm), total solids (2309mg/l), total dissolved solids (5573 mg/l), chloride (0.20mg/l), sodium (0.13ppm), calcium (2.23ppm), potassium (0.20ppm), Biological Oxygen Demand (4200mg/l), Chemical Oxygen Demand (5243 mg/l) and nickel (4.063ppm). Enumeration of total bacterial population from the electroplating effluent contaminated soil sample was made in nutrient agar medium. Sixteen bacterial colonies were selected based on their abundance growth all of them were identified through morphological and biochemical characteristics. All the sixteen bacterial isolates were screened for its metal tolerance using nutrient agar medium incorporated with nickel metal. Based on the better growth performance, six bacterial strains were selected as potential metal tolerant organism. The selected metal tolerant bacterial strains were further characterized in the various environmental conditions such as pH (5, 7 & 9) temperature (5°C, 28°C, 37°C & 45°C) and concentration of metal ions (100ppm, 200ppm, 300ppm & 400ppm) for 5 days. The result reveals that one bacterial strain, Pseudomonas sp 1 was showed better growth in nickel metal based medium with pH 7 at 37°C temperature.
Biosorption of Copper (II) Ions by Eclipta Alba Leaf Powder from Aqueous Solu...ijtsrd
The removal of heavy metals from industrial wastewater is of great concern as heavy metals are non-biodegradable, toxic elements that cause serious health problems if disposed of in the surrounding environment. The present study, Karisalangkani (Eclipta Alba) leaves were used for the adsorption of heavy metals like copper (Cu (II)) ions. The bio sorbent was characterized using SEM and BET analysis. The bio sorption experiments are conducted through batch system. The operating parameters studied were initial metal ion concentration, adsorbent dosage, initial solution pH, contact time and effect of temperature Adsorption equilibrium is achieved in 30 min and the adsorption kinetics of Cu (II) is found to follow a pseudo-second-order kinetic model. Equilibrium data for Cu (II) adsorption are fitted well by Langmuir isotherm model. The maximum adsorption capacity for Cu (II) ions is estimated to be 9.2 mgg at 25 °C. The experimental result shows that the materials have good potential to remove heavy metals from effluent and good potential as an alternate low cost adsorbent. Due to their outstanding adsorption capacities, Eclipta Alba is excellent sorbents for the removal of copper (II) ions. B. Kavitha | R. Arunadevi"Biosorption of Copper (II) Ions by Eclipta Alba Leaf Powder from Aqueous Solutions" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-2 | Issue-5 , August 2018, URL: http://www.ijtsrd.com/papers/ijtsrd17156.pdf http://www.ijtsrd.com/chemistry/environmental-chemistry/17156/biosorption-of-copper-ii-ions-by-eclipta-alba-leaf-powder-from-aqueous-solutions/b-kavitha
Multiple adsorption of heavy metal ions in aqueous solution using activated c...eSAT Journals
Abstract
Batch adsorption of different heavy metal ions (Nickel, Copper, Zinc, Lead, Cadmium and Chromium) in aqueous solution using
activated carbon from Nigerian bamboo was studied. The bamboo was cut, washed and dried. It was carbonized between 3000C -
4500C, and activated at 8000C using nitric acid. The bulk density, iodine number, Benzene adsorption, methylene adsorption, and
ash content of the activated carbon produced compared well with commercial carbons. Multiple adsorption of these metals in
same aqueous solution using bamboo carbon showed that adsorption capacity is in the order Pb>Cd>Cu>Zn>Ni>Cr which
showed that these metal ions can be adsorbed selectively by Nigerian bamboo activated carbon. The order of adsorption is related
to the maximum adsorption of lead, cadmium, copper on bamboo was found to be in the order of ionic radius of the heavy metals
used. Therefore this study demonstrates that bamboo can serve as a good source of activated carbon with multiple metal ions –
removing potentials and may serve as a better replacement for commercial activated carbons in applications that warrant their
use. However, it will also contribute to the search for less expensive adsorbents and their utilization possibilities for the
elimination of heavy metal ions from industrial waste water.
Key Words: multiple adsorption, heavy metals, Nigerian bamboo, Activated Carbon,
Lead and Heavy Metal Fixation in Soils and Solid Waste by the MAECTITE Chemic...Sevenson Environmental
Lead and other heavy metals are chemically fixated using the MAECTITE® treatment process. Treatment reactions convert leachable metal species to geochemically stable and hardened mixed mineral forms within the waste matrix that are resistant to EPTOX, TCLP, MEP, acid-leach and other test methods utilized to define RCRA toxic waste and waste product longevity. Case history data from comprehensive treatability studies support process utilization on all soil types examined, debris, and solid waste consisting of battery casings, lead projectiles, sludges, slag, paint chips with abrasives, and other waste material types. Through detailed remedial work plans and other mechanisms combining engineering, geologic, soil science, and operational construction disciplines, full-scale MAECTITE® processing at RCRA, NPL, emergency response, and other lead contaminated sites on private, state, and federally funded projects have been successfully addressed. The MAECTITE® process has been patented and registered with the U.S. Patent Trademark Office.
A promising chitosan/fluorapatite composite for efficient removal of lead (II...Dr. Md. Aminul Islam
Lead (II) is one of the most important metal ion pollutants commonly found in industrial wastewater. It is harmful to animal kingdom and prolong exposure can cause severe health trouble including cancer. Therefore, its removal to a permissible level is warranted for an eco-friendly and sustainable environment. The use of low-cost chitisan based composite material as an adsorbent can be a promising approach for Pb(II) decontamination. In this study, a novel chitosan/fluorapatite (Cs-Fap) composite has been prepared from chitosan (Cs) and fluorapatite (Fap) for the efficient removal of Pb(II) from water. Exploration of the effect of contact time, solution pH, initial Pb(II) concentration, adsorbent dosage, and the temperature was performed to understand the adsorption process. Pb(II) adsorption performance was compared among Cs, Fap and Cs-Fap composite. Pb(II) adsorption was fast and approched equlibrium in 30 min. Maximum Pb(II) adsorption was achieved at pH 4.0 for an optimum dose of 2g/L. Pb(II) adsorption kinetics data followed a pseudo-second order (PSO) model, while equilibrium isotherm data best described by Langmuir equation nicely. The maximum adsorption capacity (mg/g) follows the order: Cs-Fap (60.24) > Fap (48.31) > Cs (43.29) at pH 4.0. Thermodynamic analysis revealed that adsorption process was a feasible, endothermic and spontaneous in nature. The proposed mechanism of Pb(II) uptake involved physisorption, ion-exchange, electrostatic attraction, and surface complexation. Cs-Fap composite showed excellent regeneration capacity. After 4 (four) subsequent regeneration cycles, there was no notable loss of its adsorption capacity. The results of this study showed that the Cs-Fap composite is promising for the removal of Pb(II) and it can be used as an adsorbent for the removal of other metal ions from real environmental samples.
Suitability of leaching test methods for fly ash and slag a reviewManoj Kumar Tiwari
Fly ash and slag leachate pollution can be of great environmental concern due to generation
of these wastes in huge quantities from their respective industrial units, mainly coalbased
thermal power plants and iron and steel plants. For simulation of natural leaching in
laboratory, various leaching methods are available, but selection of a method that can
exactly simulate the real-life scenario for accurate estimation of various pollutants is
challenging; particularly, the heavy metals present and impact due to reuse or disposal of
these wastes. For choosing the most suitable leaching method according to specific situation,
one must primarily consider the chemical and physical properties of wastes, the
composition of the source, age of waste disposal, and the climatic conditions of the
disposal area. Since these factors may not be specified, a variety of leaching methods with
relevant equipment have been proposed by researchers; that are based on their required
information to particular conditions in absence of a prescribed protocol and non standardization
of equipment. The present review is an attempt to investigate the suitable
leaching method for coal fly ash and slag.
Kinetics and Thermodynamic Studies of Biosorption of Cadmium (ii) from Aqueous Solution onto Garden Grass (GAG)
Original Research Article
Journal of Chemistry and Materials Research Vol. 1 (1), 2014, 12–22
B.O. Evbuomwan, M.M. Atuka
Adsorption kinetics of Copper, Lead and Zinc by Cow Dung, Poultry Manure and ...AJSERJournal
This study highlights the effect of cow dung, cocoa pod and poultry manure in the removal of heavy
metals from solution and their applicability to Langmuir and Freundlich models was studied in the Soil Science
Laboratory of Michael Okpara University of Agriculture, Umudike in Abia State, Ngeria. The amendments used in the
study were locally sourced, sundried, ground and sieved with 2mm sieve. The salts of the three heavy metals were
separately used to prepare heavy metal solutions of 100 mg/L. Batch study was carried out at room temperature on a
mechanical shaker using 120 ml plastic bottles at different time intervals of 15, 30 and 60minutes. After shaking, the
amendments and heavy metal solutions were separated using whatman No 1 filter paper, stored in the refrigerator and
analyzed for heavy metals concentration. The amount of heavy metals adsorbed was calculated. The results revealed
that high adsorption occur at low equilibrium concentrations in all the amendments with decreasing levels of
adsorption with increasing equilibrium with cow dung and cocoa pod having higher adsorption capacity than poultry
manure. Coefficient of determination (R2) showed that the experimental data fit in to both Langmuir and Freundlich
models. For reduced heavy metal uptake by plants and subsequent contamination of the food chain, cow dung, cocoa
pod and poultry manure should be used as amendments in heavy metal contaminated soils
The radiolytic mineralization of 2-mercaptobenzothiazole, an emerging contami...IRJESJOURNAL
Abstract:The ability of high-energy ionizing radiation has been demonstrated for environmental remediation processing. γ-rayswere applied to treat a solution of 2-mercaptobenzothiazole (2-MBT). 2-MBT (125 µM) was decomposed and mineralized by the γ-radiation. The absorbed doses for 50 and 90% 2-MBT degradation were 0.170 and 0.650 kGy, respectively. Organic by-products were almost fully mineralized when high-absorbed doses in the range of 5-60 kGy were applied. Sulfate radicals (SO4 ●– ) produced through the rapid reaction of persulfate ions (S2O8 2– ) with hydrated electrons(eaq − ; keaq − /S2O8 2– = 1.1 × 1010 M −1 .s−1 ) had a significant effect on the 2-MBT mineralization yield. Because of 2-MBT decomposition,sulfate ions (SO4 2− ) were formed, and thepH and dissolved oxygen concentration were decreased. The degradation efficiency decreased when HCO3 –was added to the 2- MBT solution. No significant effects of NO3 – and Cl– ions on 2-MBT radiolytic eliminationwere observed
The Influence of Vermiculite on the Uptake of Silver Nanoparticles in a Terre...Agriculture Journal IJOEAR
— The uptake of silver from silver nanoparticles in soil was investigated in the presence of increasing concentrations of Vermiculite, typical 2:1 clay. Two insect species, Acheta domesticus and Tenebrio molitor, and two plant species, Helianthus annuus and Sorghum vulgare, were exposed to silver nanoparticles in the presence of increasing concentrations of Vermiculite in soil. Silver nanoparticles were characterized using techniques including transmission electron microscopy, dynamic light scattering, and powder X-ray diffraction. The levels of silver in test species exposed to silver nanoparticles were measured using an inductively coupled plasma-optical emission spectrometer. An increase in the cation exchange capacity of soil was observed with the increase in the concentration of vermiculite in soil. The results suggested a decrease in the uptake of silver from silver nanoparticles in soil by Acheta domesticus as a function of increasing concentrations of Vermiculite in soil. No apparent trend was observed in the remaining species. Both plant species were found to accumulate silver in their roots. The translocation of silver to stems and leaves was observed in the case of Helianthus annuus. Results from this study suggest that the presence of Vermiculite in soil could possibly decrease the uptake of silver from silver nanoparticles.
Isolation and Characterization of Nickel Tolerant Bacterial Strains from Elec...Agriculture Journal IJOEAR
Abstract— In the present study, an attempt was made to isolate and characterize nickel tolerant bacterial strains from the electroplating effluent contaminated soil. The effluent sample was collected at the direct outlet of electroplating industry and analyzed for physico-chemical characteristics such as pH (6.5), temperature (33), electrical conductivity (15.1 ms/cm), total solids (2309mg/l), total dissolved solids (5573 mg/l), chloride (0.20mg/l), sodium (0.13ppm), calcium (2.23ppm), potassium (0.20ppm), Biological Oxygen Demand (4200mg/l), Chemical Oxygen Demand (5243 mg/l) and nickel (4.063ppm). Enumeration of total bacterial population from the electroplating effluent contaminated soil sample was made in nutrient agar medium. Sixteen bacterial colonies were selected based on their abundance growth all of them were identified through morphological and biochemical characteristics. All the sixteen bacterial isolates were screened for its metal tolerance using nutrient agar medium incorporated with nickel metal. Based on the better growth performance, six bacterial strains were selected as potential metal tolerant organism. The selected metal tolerant bacterial strains were further characterized in the various environmental conditions such as pH (5, 7 & 9) temperature (5°C, 28°C, 37°C & 45°C) and concentration of metal ions (100ppm, 200ppm, 300ppm & 400ppm) for 5 days. The result reveals that one bacterial strain, Pseudomonas sp 1 was showed better growth in nickel metal based medium with pH 7 at 37°C temperature.
Biosorption of Copper (II) Ions by Eclipta Alba Leaf Powder from Aqueous Solu...ijtsrd
The removal of heavy metals from industrial wastewater is of great concern as heavy metals are non-biodegradable, toxic elements that cause serious health problems if disposed of in the surrounding environment. The present study, Karisalangkani (Eclipta Alba) leaves were used for the adsorption of heavy metals like copper (Cu (II)) ions. The bio sorbent was characterized using SEM and BET analysis. The bio sorption experiments are conducted through batch system. The operating parameters studied were initial metal ion concentration, adsorbent dosage, initial solution pH, contact time and effect of temperature Adsorption equilibrium is achieved in 30 min and the adsorption kinetics of Cu (II) is found to follow a pseudo-second-order kinetic model. Equilibrium data for Cu (II) adsorption are fitted well by Langmuir isotherm model. The maximum adsorption capacity for Cu (II) ions is estimated to be 9.2 mgg at 25 °C. The experimental result shows that the materials have good potential to remove heavy metals from effluent and good potential as an alternate low cost adsorbent. Due to their outstanding adsorption capacities, Eclipta Alba is excellent sorbents for the removal of copper (II) ions. B. Kavitha | R. Arunadevi"Biosorption of Copper (II) Ions by Eclipta Alba Leaf Powder from Aqueous Solutions" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-2 | Issue-5 , August 2018, URL: http://www.ijtsrd.com/papers/ijtsrd17156.pdf http://www.ijtsrd.com/chemistry/environmental-chemistry/17156/biosorption-of-copper-ii-ions-by-eclipta-alba-leaf-powder-from-aqueous-solutions/b-kavitha
Multiple adsorption of heavy metal ions in aqueous solution using activated c...eSAT Journals
Abstract
Batch adsorption of different heavy metal ions (Nickel, Copper, Zinc, Lead, Cadmium and Chromium) in aqueous solution using
activated carbon from Nigerian bamboo was studied. The bamboo was cut, washed and dried. It was carbonized between 3000C -
4500C, and activated at 8000C using nitric acid. The bulk density, iodine number, Benzene adsorption, methylene adsorption, and
ash content of the activated carbon produced compared well with commercial carbons. Multiple adsorption of these metals in
same aqueous solution using bamboo carbon showed that adsorption capacity is in the order Pb>Cd>Cu>Zn>Ni>Cr which
showed that these metal ions can be adsorbed selectively by Nigerian bamboo activated carbon. The order of adsorption is related
to the maximum adsorption of lead, cadmium, copper on bamboo was found to be in the order of ionic radius of the heavy metals
used. Therefore this study demonstrates that bamboo can serve as a good source of activated carbon with multiple metal ions –
removing potentials and may serve as a better replacement for commercial activated carbons in applications that warrant their
use. However, it will also contribute to the search for less expensive adsorbents and their utilization possibilities for the
elimination of heavy metal ions from industrial waste water.
Key Words: multiple adsorption, heavy metals, Nigerian bamboo, Activated Carbon,
Lead and Heavy Metal Fixation in Soils and Solid Waste by the MAECTITE Chemic...Sevenson Environmental
Lead and other heavy metals are chemically fixated using the MAECTITE® treatment process. Treatment reactions convert leachable metal species to geochemically stable and hardened mixed mineral forms within the waste matrix that are resistant to EPTOX, TCLP, MEP, acid-leach and other test methods utilized to define RCRA toxic waste and waste product longevity. Case history data from comprehensive treatability studies support process utilization on all soil types examined, debris, and solid waste consisting of battery casings, lead projectiles, sludges, slag, paint chips with abrasives, and other waste material types. Through detailed remedial work plans and other mechanisms combining engineering, geologic, soil science, and operational construction disciplines, full-scale MAECTITE® processing at RCRA, NPL, emergency response, and other lead contaminated sites on private, state, and federally funded projects have been successfully addressed. The MAECTITE® process has been patented and registered with the U.S. Patent Trademark Office.
A promising chitosan/fluorapatite composite for efficient removal of lead (II...Dr. Md. Aminul Islam
Lead (II) is one of the most important metal ion pollutants commonly found in industrial wastewater. It is harmful to animal kingdom and prolong exposure can cause severe health trouble including cancer. Therefore, its removal to a permissible level is warranted for an eco-friendly and sustainable environment. The use of low-cost chitisan based composite material as an adsorbent can be a promising approach for Pb(II) decontamination. In this study, a novel chitosan/fluorapatite (Cs-Fap) composite has been prepared from chitosan (Cs) and fluorapatite (Fap) for the efficient removal of Pb(II) from water. Exploration of the effect of contact time, solution pH, initial Pb(II) concentration, adsorbent dosage, and the temperature was performed to understand the adsorption process. Pb(II) adsorption performance was compared among Cs, Fap and Cs-Fap composite. Pb(II) adsorption was fast and approched equlibrium in 30 min. Maximum Pb(II) adsorption was achieved at pH 4.0 for an optimum dose of 2g/L. Pb(II) adsorption kinetics data followed a pseudo-second order (PSO) model, while equilibrium isotherm data best described by Langmuir equation nicely. The maximum adsorption capacity (mg/g) follows the order: Cs-Fap (60.24) > Fap (48.31) > Cs (43.29) at pH 4.0. Thermodynamic analysis revealed that adsorption process was a feasible, endothermic and spontaneous in nature. The proposed mechanism of Pb(II) uptake involved physisorption, ion-exchange, electrostatic attraction, and surface complexation. Cs-Fap composite showed excellent regeneration capacity. After 4 (four) subsequent regeneration cycles, there was no notable loss of its adsorption capacity. The results of this study showed that the Cs-Fap composite is promising for the removal of Pb(II) and it can be used as an adsorbent for the removal of other metal ions from real environmental samples.
Suitability of leaching test methods for fly ash and slag a reviewManoj Kumar Tiwari
Fly ash and slag leachate pollution can be of great environmental concern due to generation
of these wastes in huge quantities from their respective industrial units, mainly coalbased
thermal power plants and iron and steel plants. For simulation of natural leaching in
laboratory, various leaching methods are available, but selection of a method that can
exactly simulate the real-life scenario for accurate estimation of various pollutants is
challenging; particularly, the heavy metals present and impact due to reuse or disposal of
these wastes. For choosing the most suitable leaching method according to specific situation,
one must primarily consider the chemical and physical properties of wastes, the
composition of the source, age of waste disposal, and the climatic conditions of the
disposal area. Since these factors may not be specified, a variety of leaching methods with
relevant equipment have been proposed by researchers; that are based on their required
information to particular conditions in absence of a prescribed protocol and non standardization
of equipment. The present review is an attempt to investigate the suitable
leaching method for coal fly ash and slag.
Kinetics and Thermodynamic Studies of Biosorption of Cadmium (ii) from Aqueous Solution onto Garden Grass (GAG)
Original Research Article
Journal of Chemistry and Materials Research Vol. 1 (1), 2014, 12–22
B.O. Evbuomwan, M.M. Atuka
Adsorption kinetics of Copper, Lead and Zinc by Cow Dung, Poultry Manure and ...AJSERJournal
This study highlights the effect of cow dung, cocoa pod and poultry manure in the removal of heavy
metals from solution and their applicability to Langmuir and Freundlich models was studied in the Soil Science
Laboratory of Michael Okpara University of Agriculture, Umudike in Abia State, Ngeria. The amendments used in the
study were locally sourced, sundried, ground and sieved with 2mm sieve. The salts of the three heavy metals were
separately used to prepare heavy metal solutions of 100 mg/L. Batch study was carried out at room temperature on a
mechanical shaker using 120 ml plastic bottles at different time intervals of 15, 30 and 60minutes. After shaking, the
amendments and heavy metal solutions were separated using whatman No 1 filter paper, stored in the refrigerator and
analyzed for heavy metals concentration. The amount of heavy metals adsorbed was calculated. The results revealed
that high adsorption occur at low equilibrium concentrations in all the amendments with decreasing levels of
adsorption with increasing equilibrium with cow dung and cocoa pod having higher adsorption capacity than poultry
manure. Coefficient of determination (R2) showed that the experimental data fit in to both Langmuir and Freundlich
models. For reduced heavy metal uptake by plants and subsequent contamination of the food chain, cow dung, cocoa
pod and poultry manure should be used as amendments in heavy metal contaminated soils
2018 - Flexible and porous cellulose aerogels-zeolitic imidazolate framework ...DrChimie
la courbe d'étalonnage peut être configurée en mesurant ou en entrant jusqu'à 10 étalons ou en entrant K et B facteursla courbe d'étalonnage peut être configurée en mesurant ou en entrant jusqu'à 10 étalons ou en entrant K et B facteurs
REMOVAL OF POLLUTANTS USING RADIAL AND VERTICAL FLOW REGIME REACTORSIAEME Publication
Batch and continuous processes were conducted to study the adsorption of methylene blue dye on to three adsorbent materials, commercial activated carbon, chemically activated corncob carbon with phosphoric acid and ion exchange resin (akualite). Batch processes were established to show the effects of solution pH, contact time, adsorbent dosage, agitation speed and initial dye concentration. Two isotherm models, Freundlich and Langmuir fitted with the experimental data found from batch processes, the Langmuir model fitted well than the Freundlich, with maximum adsorption capacities of 16.21, 30.95 and 77.52 mg/g and R2 of 0.952, 0.992 and 0.995 predicted by commercial activated carbon, corncob activated carbon akualite respectively.
Lifecycle Assessment of Solar PV Systems: From Manufacturing to RecyclingChristo Ananth
Christo Ananth, Rajini K R Karduri, "Lifecycle Assessment of Solar PV Systems: From
Manufacturing to Recycling", International Journal of Advanced Research in Basic Engineering Sciences and Technology (IJARBEST), Volume 6,Issue 2,February 2020,pp:51-60
HYDROGEN GENERATION FROM WASTE WATER BY USING SOLAR ENERGY | J4RV3I11004Journal For Research
Objective of this paper is to produce hydrogen which is an ideal fuel for the next generation because it is abundantly available in nature, energy efficient and clean. Wide varieties of technologies are available to produce hydrogen but only few of them are considered environmental friendly. Solar water splitting via photo catalytic reaction is one of them which have attracted tremendous attention. In this paper we are working on hydrogen production via solar splitting. Photo catalytic water splitting is one of the promising technologies to produce pure and clean hydrogen. Since it is reasonable having low process cost and has a small reactor, it can be made for house hold application and hence has a huge market potential. Generation of hydrogen under visible irradiation is the main area of work. Based on the literature reported here, visible irradiation can be achieved by doping of TiO2 with metal or non-metal. We have used Fe doping to increase the efficiency. The result indicates that Fe doped sieves produce more hydrogen than the normal TiO2 coated sieve and the efficiency can be increased if we increase the number of doped sieves and surface area.
Nanofiber controlling heavy metal contaminationMr. Lucky
Plenty of fresh water resources are still inaccessible for human use. Calamities such as pollution, climate change, and global warming pose serious threats to the fresh water system. Although many naturally and synthetically grown materials have been taken up to resolve these issues, there is still plenty of room for enhancements in technology and material perspectives to maximize resources and to minimize harm. Considering the challenges related to the purification of water, materials in the form of nanofiber membranes and nanomaterials have made tremendous contributions to water purification. Nanofiber membranes made of synthetic polymer nanofibers, ceramic membranes etc., metal oxides in various morphologies, and carbonaceous materials were explored in relation to waste removal from water. Membranes for membrane adsorption (MA) have the dual function of membrane filtration and adsorption to be very effective to remove trace amounts of pollutants such as cationic heavy metals, anionic phosphates and nitrates. In addition, recent progresses in the development of advanced adsorbents such as nanoparticles are summarized, since they are potentially useful as fillers in the host membrane to enhance its performance.
Review of research on bio reactors used in wastewater ijsit 2.4.6IJSIT Editor
The review presented in this paper focuses on reactors used in wastewater treatment for bio
hydrogen production (e.g. batch reactors, complete mix reactors, plug flow reactors, bio-film reactors,
suspended reactors, upflow anaerobic sludge blanket reactor, anaerobic baffled reactors, upflow packed-bed
attached growth reactors, attached growth fluidized bed reactors, anaerobic sequencing batch reactor, hybrid
/ high rate reactors and membrane separation reactors. It is clear from the review that development of these
reactors can be considered a grown up research for which good design and scale-up guidelines are available
Low Cost Anaerobic Treatment of Municipal Solid Waste Leachateiosrjce
IOSR Journal of Environmental Science, Toxicology and Food Technology (IOSR-JESTFT) multidisciplinary peer-reviewed Journal with reputable academics and experts as board member. IOSR-JESTFT is designed for the prompt publication of peer-reviewed articles in all areas of subject. The journal articles will be accessed freely online
Optimization of Na-Alginate Immobilization Method for Sulfide Oxidation Using...Premier Publishers
The study was aimed to investigate the optimization of Na-alginate immobilization method for biological sulfide oxidation process using an immobilized Thiobacillus species and the effects of four factors including Na-alginate concentration, CaCl2 concentration, agitation speed and amount of inoculum on sulfide conversion. The strength of sodium-alginate immobilization method for Thiobacillus species was evaluated. For this purpose, experiments were designed by a central composite design (CCD) and results were optimized by using response surface methodology (RSM). Design of experiments (DOE) was used to model and optimize the operational conditions. The central composite design (CCD) was very good for the optimization of variables; the R2 value for the developed model was 0.91. The results and analysis showed the optimized values for the sulfide oxidation. 95% Sulfide oxidation was achieved with optimized values. Beside this a useful by- product was produced from waste effluents.
How do you get a job in data science? Knowing enough statistics, machine learning, programming, etc to be able to get a job is difficult. One thing I have found lately is quite a few people may have the required skills to get a job, but no portfolio. While a resume matters, having a portfolio of public evidence of your data science skills can do wonders for your job prospects. Even if you have a referral, the ability to show potential employers what you can do instead of just telling them you can do something is important. This is a talk based on my original blog on Building a Data Science Portfolio: https://towardsdatascience.com/how-to-build-a-data-science-portfolio-5f566517c79c