First Pilot Test on the Integration of GCW (Groundwater
Circulation Well) with ENA (Enhanced Natural Attenuation) for
Chlorinated Solvents Source Remediation.
An overview of the SABRE project - an integrated laboratory and field investigation with process modelling and performance assessment of DNAPL source zone bioremediation.
CHARACTERISTICS OF THE LEACHATE FROM MSW LANDFILL,BANGALORE Dr. Naveen BP
Bangalore city generates about 4,500 metric tons of municipal solid waste every day in that 75% is disposed in the landfill. The landfill leachate discharge may lead to serious environmental problems. Leachate may percolate through landfill liners and subsoil causing pollution of ground water and surface waters resources. The aim of this research study is to identify the characteristics of the leachate from landfill in Mavallipura. Landfill leachate contains various pollutants that can be categorized into four groups such as dissolved organic matter, inorganic macrocomponents, heavy metals, and organic compounds. The pH of the leachate is considered as alkaline as the pH is 7.6 in Mavallipura landfill leachate. The results showed that the highest metal concentration that exists in the leachate was Iron which is about of 12 ppm. BOD
and COD of the leachate are 1500 mg/L and 10400 mg/L, respectively. The leachate characteristics indicate favourable growth of algae in natural water contaminated with leachate with the alkaline condition and with the presence of magnesium as nutrient, which has been confirmed in the nearby surface pond.
International Refereed Journal of Engineering and Science (IRJES)irjes
International Refereed Journal of Engineering and Science (IRJES) is a leading international journal for publication of new ideas, the state of the art research results and fundamental advances in all aspects of Engineering and Science. IRJES is a open access, peer reviewed international journal with a primary objective to provide the academic community and industry for the submission of half of original research and applications
An overview of the SABRE project - an integrated laboratory and field investigation with process modelling and performance assessment of DNAPL source zone bioremediation.
CHARACTERISTICS OF THE LEACHATE FROM MSW LANDFILL,BANGALORE Dr. Naveen BP
Bangalore city generates about 4,500 metric tons of municipal solid waste every day in that 75% is disposed in the landfill. The landfill leachate discharge may lead to serious environmental problems. Leachate may percolate through landfill liners and subsoil causing pollution of ground water and surface waters resources. The aim of this research study is to identify the characteristics of the leachate from landfill in Mavallipura. Landfill leachate contains various pollutants that can be categorized into four groups such as dissolved organic matter, inorganic macrocomponents, heavy metals, and organic compounds. The pH of the leachate is considered as alkaline as the pH is 7.6 in Mavallipura landfill leachate. The results showed that the highest metal concentration that exists in the leachate was Iron which is about of 12 ppm. BOD
and COD of the leachate are 1500 mg/L and 10400 mg/L, respectively. The leachate characteristics indicate favourable growth of algae in natural water contaminated with leachate with the alkaline condition and with the presence of magnesium as nutrient, which has been confirmed in the nearby surface pond.
International Refereed Journal of Engineering and Science (IRJES)irjes
International Refereed Journal of Engineering and Science (IRJES) is a leading international journal for publication of new ideas, the state of the art research results and fundamental advances in all aspects of Engineering and Science. IRJES is a open access, peer reviewed international journal with a primary objective to provide the academic community and industry for the submission of half of original research and applications
Reflux it's impact on the removal of nitrogen and phosphorus from sewage wat...eSAT Journals
Abstract A/O BAF system has been used in the treatment of nitrogen and phosphorus and other nutrients present in wastewater, This economical and effective way of nutrients removal uses different parameters in the actualization of desired objectives, one of them is the Reflux ratio, this research focuses on the influence and roles of Reflux, Sponge Iron and Manganese sand on the removal of nitrogen and phosphorus from wastewater. The following experimental operational parameters was set up for the purpose of this experiment, Hydraulic load of 0.5 m3 / m2 • h., Air/Water ratio of 10:1 (0.42L/min) and reflux ratio of 100 and 200 percent. The experiment is divided into two main areas: The effects of reflux ratio presence and absences on removal efficiency of the BAF system. The reflux water was introduced into the anaerobic column and sometimes in aerobic column. The results were examined to note the extent to which reflux plays a part on the removal rate of the nutrients when introduced into the aerobic column instead of the anaerobic column and vice versa. sponge iron and manganese sand column were also introduced, and the results of the nitrifying bacteria shown it supports the removal efficiency observed in the BAF system. The results were all investigated, compared and the analysis showed that reflux helped more in the removal of nitrogen and ammonia, while sponge iron and manganese sand increased the removal efficiency of phosphorus from waste water Key Word: BAF: Biological Aeration Filter; Total Phosphorus; Total Nitrogen; Chemical Oxygen Demand (COD); Removal Efficiency;
Hydrogeochemistry and Microbiology of Wadi Al Bih Limestone Aquifer in Northe...QUESTJOURNAL
ABSTRACT: This study investigated the hydrogeochemical characteristics and microbiological pollution of groundwater in Wadi Al Bih limestone aquifer, Ras Al Khaimah area, northern United Arab Emirates (UAE). Results indicate that the decrease of groundwater exploitation in Wadi Al Bih basin from 58 million cubic meter (MCM) during the period 1991-1995 to 22 MCM during the period 2011-2015, has increased groundwater storage, raised hydraulic heads by 1 m in Al Burayrat area and 16 m near Wadi Al Bih main dam, and decreased the average groundwater salinity by 30% in Wadi Al Bih well field and 45% in Al Burayrat well field. Results of chemical analyses showed noticeable fluctuations in groundwater temperature, EC, and TDS contents, rather than concentrations of all ions. The November 2014 and June 2015 isosalinity contour maps indicate that the groundwater salinity increases from east to west, in the direction of groundwater flow. The groundwater in the eastern part of Wadi Al Bih is good for domestic purposes and irrigation. However, the water hardness is high because the aquifer is predominantly composed of limestone. Wadi Al Bih limestone aquifer is highly sensitive to urban and agricultural activities, and several well were recorded to have Coliform bacteria in Wadi Al Bih and Al Burayrat areas
A Study of Application of Tracers in Groundwater HydrologyAJSERJournal
Laboratory study was carried out to investigate the effect of acidic and alkaline characteristics of
groundwater medium on three tracers (rhodamine B, eosin and potassium dichromate) commonly used for
groundwater investigations. This is with the view to improving the criterion used in the selection of tracers for
groundwater investigations. The factors considered are: the maximum tracer concentration, Cmax, which could be
observed during the experiment, the time, tm, at which this occurs and the percentage of the tracer recovered during
experiment. Others are the time, ti, of first detection of the tracer and time, tf, of total disappearance of tracer from the
investigation area.A lysimeter apparatus of circular cross section with diameter, D = 45 mm was constructed and
uniformly filled with coarse sand and fine gravel (each at a time). Throughout the column, steady water discharge (2.5
ml/min) at a pH value between the ranges of 5 – 8 was maintained, to carry the tracer solution through the soil column.
Effluent from the bottom of the lysimeter were subjected to spectrometric analysis to determine tracer concentration..
The results suggest that rhodamine B is a suitable tracer for groundwater investigation in acidic medium but may not
be suitable for alkaline medium. Values obtained for eosin showed the tracer to be good for investigation in both acidic
and alkaline medium,while potassium dichromate as a tracer may be a good tracer in alkaline medium only.
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.
Leachate management of Constructed wetlands_Yuka Ogata_National Institute for...CRL Asia
Research conducted by National Institute for Environmental Studies, Yuka Ogata on developing constructed wetlands. A research with pilot scale Constructed Wetlands at Sainoi landfill site in Nonthaburi province next to Bangkok city is introduced here.
Removal of 137Cs from contaminated soil using pilot electrokinetic decontamin...Agriculture Journal IJOEAR
—The removal efficiencies of 137Cs for 10 days were 50-70%. The removal efficiencies according to the elapsed time after 10 days were reduced. When an electric current density of 25-75 mA/cm2, sulfuric acid, nitric acid, acetic acid as electrolyte, a 0.5-2.0 cm/min hydraulic conductivity of soil were applied, respectively, the time required for the removal efficiency of 137Cs to reach 80% was 20-30 days. For improving removal efficiency of 137Cs from contaminated soil, it is necessary to increase an electric current density using sulfuric acid as an electrolyte and to decrease hydraulic conductivity of soil in the soil cell.
Reflux it's impact on the removal of nitrogen and phosphorus from sewage wat...eSAT Journals
Abstract A/O BAF system has been used in the treatment of nitrogen and phosphorus and other nutrients present in wastewater, This economical and effective way of nutrients removal uses different parameters in the actualization of desired objectives, one of them is the Reflux ratio, this research focuses on the influence and roles of Reflux, Sponge Iron and Manganese sand on the removal of nitrogen and phosphorus from wastewater. The following experimental operational parameters was set up for the purpose of this experiment, Hydraulic load of 0.5 m3 / m2 • h., Air/Water ratio of 10:1 (0.42L/min) and reflux ratio of 100 and 200 percent. The experiment is divided into two main areas: The effects of reflux ratio presence and absences on removal efficiency of the BAF system. The reflux water was introduced into the anaerobic column and sometimes in aerobic column. The results were examined to note the extent to which reflux plays a part on the removal rate of the nutrients when introduced into the aerobic column instead of the anaerobic column and vice versa. sponge iron and manganese sand column were also introduced, and the results of the nitrifying bacteria shown it supports the removal efficiency observed in the BAF system. The results were all investigated, compared and the analysis showed that reflux helped more in the removal of nitrogen and ammonia, while sponge iron and manganese sand increased the removal efficiency of phosphorus from waste water Key Word: BAF: Biological Aeration Filter; Total Phosphorus; Total Nitrogen; Chemical Oxygen Demand (COD); Removal Efficiency;
Hydrogeochemistry and Microbiology of Wadi Al Bih Limestone Aquifer in Northe...QUESTJOURNAL
ABSTRACT: This study investigated the hydrogeochemical characteristics and microbiological pollution of groundwater in Wadi Al Bih limestone aquifer, Ras Al Khaimah area, northern United Arab Emirates (UAE). Results indicate that the decrease of groundwater exploitation in Wadi Al Bih basin from 58 million cubic meter (MCM) during the period 1991-1995 to 22 MCM during the period 2011-2015, has increased groundwater storage, raised hydraulic heads by 1 m in Al Burayrat area and 16 m near Wadi Al Bih main dam, and decreased the average groundwater salinity by 30% in Wadi Al Bih well field and 45% in Al Burayrat well field. Results of chemical analyses showed noticeable fluctuations in groundwater temperature, EC, and TDS contents, rather than concentrations of all ions. The November 2014 and June 2015 isosalinity contour maps indicate that the groundwater salinity increases from east to west, in the direction of groundwater flow. The groundwater in the eastern part of Wadi Al Bih is good for domestic purposes and irrigation. However, the water hardness is high because the aquifer is predominantly composed of limestone. Wadi Al Bih limestone aquifer is highly sensitive to urban and agricultural activities, and several well were recorded to have Coliform bacteria in Wadi Al Bih and Al Burayrat areas
A Study of Application of Tracers in Groundwater HydrologyAJSERJournal
Laboratory study was carried out to investigate the effect of acidic and alkaline characteristics of
groundwater medium on three tracers (rhodamine B, eosin and potassium dichromate) commonly used for
groundwater investigations. This is with the view to improving the criterion used in the selection of tracers for
groundwater investigations. The factors considered are: the maximum tracer concentration, Cmax, which could be
observed during the experiment, the time, tm, at which this occurs and the percentage of the tracer recovered during
experiment. Others are the time, ti, of first detection of the tracer and time, tf, of total disappearance of tracer from the
investigation area.A lysimeter apparatus of circular cross section with diameter, D = 45 mm was constructed and
uniformly filled with coarse sand and fine gravel (each at a time). Throughout the column, steady water discharge (2.5
ml/min) at a pH value between the ranges of 5 – 8 was maintained, to carry the tracer solution through the soil column.
Effluent from the bottom of the lysimeter were subjected to spectrometric analysis to determine tracer concentration..
The results suggest that rhodamine B is a suitable tracer for groundwater investigation in acidic medium but may not
be suitable for alkaline medium. Values obtained for eosin showed the tracer to be good for investigation in both acidic
and alkaline medium,while potassium dichromate as a tracer may be a good tracer in alkaline medium only.
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.
Leachate management of Constructed wetlands_Yuka Ogata_National Institute for...CRL Asia
Research conducted by National Institute for Environmental Studies, Yuka Ogata on developing constructed wetlands. A research with pilot scale Constructed Wetlands at Sainoi landfill site in Nonthaburi province next to Bangkok city is introduced here.
Removal of 137Cs from contaminated soil using pilot electrokinetic decontamin...Agriculture Journal IJOEAR
—The removal efficiencies of 137Cs for 10 days were 50-70%. The removal efficiencies according to the elapsed time after 10 days were reduced. When an electric current density of 25-75 mA/cm2, sulfuric acid, nitric acid, acetic acid as electrolyte, a 0.5-2.0 cm/min hydraulic conductivity of soil were applied, respectively, the time required for the removal efficiency of 137Cs to reach 80% was 20-30 days. For improving removal efficiency of 137Cs from contaminated soil, it is necessary to increase an electric current density using sulfuric acid as an electrolyte and to decrease hydraulic conductivity of soil in the soil cell.
Opportunities abound in the age of information! You have, at your fingertips, direct access to thousands of job postings that fit your skillset. The tradeoff? Saturation. Standing out from the rest of the job-seeking crowd can be a daunting task.
How do you overcome this significant hurdle and find that dream job? The easiest way to get noticed is by tapping into the same resources that recruiters are using.
Social media platforms are so pervasive that businesses are using LinkedIn, Facebook, Twitter, and Google+ to find and screen candidates. This trend is only going to grow as more companies start to capitalise on the immense potential of this resource.
Project SABRE (Source Area BioRemediation) – an Overviewian_farrar
Project SABRE was a five-year collaborative project undertaken by a
multidisciplinary team from the UK, USA, and Canada, supported
through the DTI Bioremediation LINK programme. Its objectives were to
demonstrate that in situ enhanced anaerobic bioremediation can result
in effective treatment of chlorinated solvent dense non-aqueous phase
liquid (DNAPL) source areas and to improve related site investigation
tools and process understanding. An important feature of the SABRE
programme was the field application of DNAPL partitioning electron
donor to the source zone to provide a source of electron donor at the
DNAPL:water interface. The SABRE project is one of the most detailed
demonstrations of its kind, and the first scientifically robust development
of in situ bioremediation of a chlorinated solvent source zone in the UK.
Groundwater Circulation Well (IEG-GCW®) employing C-Mix in Lower Saxony, Germany
Addition of a nutritive preparation of C-Mix via GCW for anaerobic biodegradation of Chlorinated Hydrocarbons (CHC)
Wastewater pretreatment methods for constructed wetland: Reviewpetro karungamye
One of the most interesting research topics has been the constructed wetlands (CWs) for wastewater treatment. The primary operating issue of CWs is medium clogging, which
is caused by the accumulation of varying sorts of solids, resulting in a reduction in the infiltration capacity of the gravel substrate. It is commonly recognized that effective wastewater pretreatment is necessary for the long-term operation of CW. Pre-treatment is crucial because it prepares the influent for CW treatment. The primary treatment's goal is to reduce the solid load on the wetland, and the suspended solids concentration should not exceed 100 mg L1. This review paper describes the methods employed for wastewater pretreatment for constructed wetland performance. Three technologies namely septic tank, coagulation waste stabilization ponds and biofilters have been described
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
Artifi cial wetlands are useful for wastewater treatment; however, relatively little is known of the effects of sewage on artifi cial wetland microbial community structure. Therefore, we assessed the effect of municipal sewage on microbial community diversity in surface water throughout an artifi cial wetland (Xiantao artifi cial wetland) treating municipal sewage. We analyzed the relationship between physicochemical parameters of surface water (i.e., Chemical Oxygen Demand (COD), Total Nitrogen (TN), Total Phosphorus (TP), and
NH4+-N) with microbial community structure (Illumina MiSeq sequencing followed by abundance indices). The results showed that the total microbial community in surface water was signifi cantly correlated with COD, TN, TP, and NH4
+-N (r = 0.764, 0.897, 0.883, 0.839, P < 0.05). In addition, the most abundant taxa were significantly correlated with COD (r = 0.803, P < 0.05). The relative abundance of rare operational taxonomic units in the more purifi ed water farther downstream was higher than in the polluted area, suggesting that rare groups were more sensitive to physicochemical parameters than abundant groups, and that the abundance of some bacteria could indirectly indicate the degree of aquatic pollution. Our results indicate that the responses of microorganisms in artificial wetlands to environmental conditions should be considered to ensure efficient treatment.
UNDERSTANDING WHAT GREEN WASHING IS!.pdfJulietMogola
Many companies today use green washing to lure the public into thinking they are conserving the environment but in real sense they are doing more harm. There have been such several cases from very big companies here in Kenya and also globally. This ranges from various sectors from manufacturing and goes to consumer products. Educating people on greenwashing will enable people to make better choices based on their analysis and not on what they see on marketing sites.
Willie Nelson Net Worth: A Journey Through Music, Movies, and Business Venturesgreendigital
Willie Nelson is a name that resonates within the world of music and entertainment. Known for his unique voice, and masterful guitar skills. and an extraordinary career spanning several decades. Nelson has become a legend in the country music scene. But, his influence extends far beyond the realm of music. with ventures in acting, writing, activism, and business. This comprehensive article delves into Willie Nelson net worth. exploring the various facets of his career that have contributed to his large fortune.
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Introduction
Willie Nelson net worth is a testament to his enduring influence and success in many fields. Born on April 29, 1933, in Abbott, Texas. Nelson's journey from a humble beginning to becoming one of the most iconic figures in American music is nothing short of inspirational. His net worth, which estimated to be around $25 million as of 2024. reflects a career that is as diverse as it is prolific.
Early Life and Musical Beginnings
Humble Origins
Willie Hugh Nelson was born during the Great Depression. a time of significant economic hardship in the United States. Raised by his grandparents. Nelson found solace and inspiration in music from an early age. His grandmother taught him to play the guitar. setting the stage for what would become an illustrious career.
First Steps in Music
Nelson's initial foray into the music industry was fraught with challenges. He moved to Nashville, Tennessee, to pursue his dreams, but success did not come . Working as a songwriter, Nelson penned hits for other artists. which helped him gain a foothold in the competitive music scene. His songwriting skills contributed to his early earnings. laying the foundation for his net worth.
Rise to Stardom
Breakthrough Albums
The 1970s marked a turning point in Willie Nelson's career. His albums "Shotgun Willie" (1973), "Red Headed Stranger" (1975). and "Stardust" (1978) received critical acclaim and commercial success. These albums not only solidified his position in the country music genre. but also introduced his music to a broader audience. The success of these albums played a crucial role in boosting Willie Nelson net worth.
Iconic Songs
Willie Nelson net worth is also attributed to his extensive catalog of hit songs. Tracks like "Blue Eyes Crying in the Rain," "On the Road Again," and "Always on My Mind" have become timeless classics. These songs have not only earned Nelson large royalties but have also ensured his continued relevance in the music industry.
Acting and Film Career
Hollywood Ventures
In addition to his music career, Willie Nelson has also made a mark in Hollywood. His distinctive personality and on-screen presence have landed him roles in several films and television shows. Notable appearances include roles in "The Electric Horseman" (1979), "Honeysuckle Rose" (1980), and "Barbarosa" (1982). These acting gigs have added a significant amount to Willie Nelson net worth.
Television Appearances
Nelson's char
"Understanding the Carbon Cycle: Processes, Human Impacts, and Strategies for...MMariSelvam4
The carbon cycle is a critical component of Earth's environmental system, governing the movement and transformation of carbon through various reservoirs, including the atmosphere, oceans, soil, and living organisms. This complex cycle involves several key processes such as photosynthesis, respiration, decomposition, and carbon sequestration, each contributing to the regulation of carbon levels on the planet.
Human activities, particularly fossil fuel combustion and deforestation, have significantly altered the natural carbon cycle, leading to increased atmospheric carbon dioxide concentrations and driving climate change. Understanding the intricacies of the carbon cycle is essential for assessing the impacts of these changes and developing effective mitigation strategies.
By studying the carbon cycle, scientists can identify carbon sources and sinks, measure carbon fluxes, and predict future trends. This knowledge is crucial for crafting policies aimed at reducing carbon emissions, enhancing carbon storage, and promoting sustainable practices. The carbon cycle's interplay with climate systems, ecosystems, and human activities underscores its importance in maintaining a stable and healthy planet.
In-depth exploration of the carbon cycle reveals the delicate balance required to sustain life and the urgent need to address anthropogenic influences. Through research, education, and policy, we can work towards restoring equilibrium in the carbon cycle and ensuring a sustainable future for generations to come.
Artificial Reefs by Kuddle Life Foundation - May 2024punit537210
Situated in Pondicherry, India, Kuddle Life Foundation is a charitable, non-profit and non-governmental organization (NGO) dedicated to improving the living standards of coastal communities and simultaneously placing a strong emphasis on the protection of marine ecosystems.
One of the key areas we work in is Artificial Reefs. This presentation captures our journey so far and our learnings. We hope you get as excited about marine conservation and artificial reefs as we are.
Please visit our website: https://kuddlelife.org
Our Instagram channel:
@kuddlelifefoundation
Our Linkedin Page:
https://www.linkedin.com/company/kuddlelifefoundation/
and write to us if you have any questions:
info@kuddlelife.org
Characterization and the Kinetics of drying at the drying oven and with micro...Open Access Research Paper
The objective of this work is to contribute to valorization de Nephelium lappaceum by the characterization of kinetics of drying of seeds of Nephelium lappaceum. The seeds were dehydrated until a constant mass respectively in a drying oven and a microwawe oven. The temperatures and the powers of drying are respectively: 50, 60 and 70°C and 140, 280 and 420 W. The results show that the curves of drying of seeds of Nephelium lappaceum do not present a phase of constant kinetics. The coefficients of diffusion vary between 2.09.10-8 to 2.98. 10-8m-2/s in the interval of 50°C at 70°C and between 4.83×10-07 at 9.04×10-07 m-8/s for the powers going of 140 W with 420 W the relation between Arrhenius and a value of energy of activation of 16.49 kJ. mol-1 expressed the effect of the temperature on effective diffusivity.
WRI’s brand new “Food Service Playbook for Promoting Sustainable Food Choices” gives food service operators the very latest strategies for creating dining environments that empower consumers to choose sustainable, plant-rich dishes. This research builds off our first guide for food service, now with industry experience and insights from nearly 350 academic trials.
2. appropriate remediation strategy to enhance ISB in an operative industrial site heavily contaminated by a wide
spectrum of CAHs located in the northern part of Italy.
A large source zone, probably characterized by a significant amount of residual DNAPL, has been identified
below operative industrial warehouses in a quite complex hydrogeological setting, from high permeable
transmissive zone to low permeable zone. As a consequence, even though an intensive pumping is active
since 9 years to avoid contaminant spreading outside the site, dissolved CAHs concentration still remain
significantly high. A typical specific site hydrogeological setting is reported in Figure 1; it shows a multiple-
layered heterogeneous aquifer which consists of materials that vary in their water-transmitting properties
laterally and vertically (fine to middle sands with intercalation of less permeable sandy silts to clayey silts
layers with permeability in range of 10-7
-10-4
m/s). In this situation, trapped DNAPL in low k zones act as
continuous persistent source releasing contaminants in the more permeable layers by slow back diffusion;
contamination present at the site consists of quantities of pooled or trapped DNAPL-phase (hotspots) and
various dissolved plumes are generated from the residual phase.
Figure 1: A representative geological cross section across the main contamination area
Site characterization surveys also indicated that natural attenuation is already ongoing in the investigated site:
the presence of cis-DCE (cis-dichloroethene) and VC (vinyl chloride) indicates an intense but incomplete
microbial dechlorination activity, who had leaded the formation of more toxic compounds such as VC. Due to
the decreasing of the reductive dechlorination rate, under anaerobic conditions, an accumulation of cis-DCE or
VC is often observed at CAHs contaminated sites [Tiehm et al 2011]. Therefore, laboratory microcosm
experiments were set up to assess the possibility to significantly enhance the biodegradative potential of
natural microbiota with the addition of electron donors as well as the interactions of dechlorinating populations
with other microbial populations which can compete for the supplied electron donor [Fennel et al. 1997;
Aulenta et al.2002, Heimann et al 2007] and their effect on the dechlorination process in the subsurface.
Microcosms were also used to evaluate the applicability of PHB as carbon releasing source at the studied site.
PHB is a biopolymer produced (synthesized) by numerous microorganisms as an intracellular energy-storage
material under unbalanced growth conditions [Brennan et al 2006], such as limited essential nutrients or
excess carbon sources. This polymer was chosen as electron donors based on previous studies [Aulenta et
al, 2008; Baric et al 2012, 2014] conducted at the lab scale which clearly demonstrated the ability of PHB
fermentation products (volatile fatty acids, VFA and molecular hydrogen) to stimulate/sustain CAHs biological
reduction dechlorination. Based on the geophysical characterization of the site and the distribution of the
contamination, two locations were selected for saturated soil sampling for the microcosm investigation: one
close to piezometer (Pz 6) downgradient the hydraulic barrier at the outer boundary of the site and the other
one close to piezometer (Pz 14) inside an industrial warehouse close to the source area (metal industrial
washing machines). Results of microcosm study indicated how an approach based on the delivery of electron
donor in the area characterized by the presence of very high concentration of chlorinated solvents (source
zone) could be successful in quantitatively degrade the contaminants in harmless compounds such as ethene
and ethane (Figure2).
92
3. Figure2: Reductive dehalogenation of chlorinated solvents and acetic acid in anaerobic reactors amended with
PHB. Error bars indicate the difference between two duplicate microcosms.
Based on the satisfactory results of the laboratory investigations, indicating that reductive dechlorination might
be enhanced successfully at the considered site, the design of a pilot test was performed in order to select the
best remediation strategy. As well known, one of requirements for successful in situ bioremediation
implementation for chlorinated DNAPLs is the homogenous electron donor distribution. In this case, because
of geochemistry and hydrogeology of site, the conventional addition methods are not suitable; traditional
injection approaches are often limited by preferential migration of injected fluids through better permeable
zones, while delivery through less permeable and contaminated layers is usually limited. On the other hand,
Groundwater Circulation Well remediation technology allows creating in-situ vertical groundwater circulation
cells by drawing groundwater from an aquifer through one screened section of a multi-screened well and
discharging. The typical GCW configuration consists of installation of a single operating well with at least two
isolated screen section. Groundwater is extracted from one screen and after treatment (or amendment) it is
injected back into the aquifer through the second screen, creating a three-dimensional flow pattern (circulation
cell) in the aquifer. The pressure gradient between two hydraulically separated screen sections in the well
induces a circulation flow in the aquifer [Xiang and Kabala 1997, US EPA1998]. The groundwater moves
through the treatment zone both horizontally and vertically and as a consequence the low permeable layer is
constantly penetrated by the vertical flow of the GCW (Figure 3).
Vertical
Flow
Figure3: Schematic overview of an operating Groundwater Circulation Well
Source Zone (Pz 14) Site boundary (Pz 6)
PHB:electrondonor
Time (d)
0 20 40 60 80 100
μM
0
30
60
90
120
150
180
cis-DCE
VC
Eth
Time (d)
0 20 40 60 80 100
μM
0
10
20
30
cis-DCE
VC
Eth
Time (d)
0 20 40 60 80
AceticAcid[μM]
0,0
0,5
1,0
1,5
2,0
2,5
3,0
3,5
Time (d)
0 20 40 60 80 100
AceticAcid[μM]
0,0
0,5
1,0
1,5
2,0
2,5
3,0
3,5
93
4. 2. Pilot (Field) Test
On the basis of the geological and hydrogeological characteristics of the site, a 30 mts deep GCW was
designed in order to obtain an in-situ vertical groundwater circulation by drawing groundwater from two lower
screened sections (-24mts and -14mts) of a multi-screened well separated by packers and discharging it
through an upper screened section (-7mts). Thus, GCW worked under standard flow conditions: water flow
comes in through the lower and intermediate screen and out to the upper screen. As consequence, two
pumps were installed on the surface to extract groundwater from deep permeable layer and low permeability
intermediate layer, hereafter called pump 1 and pump 2, respectively. Following that, groundwater is pumped
upward inside an above-ground installed external treatment unit. Figure 4 illustrates the P&ID of the above-
ground set-up plant connected to the GCW. According to P&ID, nine different possibilities are made available
to change process and work under favorable condition.
Process n.1: IEG-GCW®
+ Sand Vessel
Process n.2: IEG-GCW®
+ Sand Vessel+PHB Reactor
Process n.3: IEG-GCW® + Sand Vessel+ZVI Reactor
Process n.4: IEG-GCW® + Sand Vessel+PHB and ZVI Reactors
Process n.5: InternalRecirculation PHB Reactor
Process n.6: InternalRecirculation ZVIReactor
Process n.7:Internal Recirculation PHB and ZVI Reactors
Process n.8: Wash in an up-flow mode Sand Vessel
Process n.9: IEG-GCW®
+ Sand Vessel+partial flow in PHB and ZVI Reactors
Figure 4: Piping and Instrumentation Diagram - P&ID, of the remediation plant with applicable processesand
schematic diagram of groundwater flow pattern due to use of GCW.
As shown in Figure 5, the external treatment unit is composed of a sand filter tank, a PHB reactor (where
fermentation takes place and dissolved VFA and H2 are produced) and a ZVI reactor (where CAHs are
partially removed before reinjection).
Figure 5: The external treatment unit.
94
5. 3. Results
3.1 Enrichment of groundwater with PHB fermentation products
Figure 6 depicts volatile fatty acids (VFAs) effluent concentrations as function of operating time as measured
in the outlet of the PHB reactor and even in the outlet of the vessel where the groundwater that will be
reinjected into the aquifer is collected.
A
Time (d)
0 50 100 150 200
mgL-1
0
500
1000
1500
2000
2500
3000 B
Time (d)
0 50 100 150 200
mgL-1
0
500
1000
1500
2000
2500
3000
Acetic Butyric VFAtot
Figure6: VFA effluent concentrations of PHB reactor (A) and vessel (B)
Groundwater pumped from deep (-25m) and intermediate screen (-14m) was enriched with products from the
continuous fermentation of PHB. Tuning the flow rate groundwater through PHB reactor allowed optimizing the
concentration of the produced dissolved electron donors and the spreading of biostimulants in the subsurface
can be varied accordingly.
3.2 Enhancing CAHs mobilization
Groundwater recirculation through PHB reactor allowed a continuous delivering of the PHB fermentation
products in the contaminated aquifer also in the low permeable layer due to the vertical flow induced by the
GCW installation. The field results clearly demonstrated that mobilization of chlorinated
aliphatic hydrocarbons was strongly enhanced (Figure 7).
A
Time (d)
0 50 100 150 200 250
mgL-1
0
1
2
3
cis-Dichloroethene
Vinyl chloride
B
Time (d)
0 50 100 150 200 250
mgL-1
0
10
20
30
Figure7: CAHs concentration in the groundwater extracted from the lower (A) and intermediate (B) screen
The CAHs mobilization has been proven by analysing the mass of 1,2-DCE and VC extracted during the
operation time (Table1).
Table 1: CAH mass extracted during the field test
deep permeable layer low permeability intermediate layer
Extracted volume [m3
] 4200 25
cis-DCE (g) 210 200
VC (g) 84 87.5
95
6. It is worth of noting that the calculated extracted amounts for both contaminants are very similar, but the
relative volume at the two examined depths is strongly greater for the deep screen (-24 mts) than the
intermediate screen (-14 mts).
4. Conclusions
The installed GCW combined with the external treatment unit allowed the effective amendment of groundwater
with the PHB fermentation products. The combined effect of groundwater recirculation with VFA production
(probably by a co-solvent effect) clearly enhanced the mobilization of pollutants from less accessible low
permeable zone where a significant mass of contaminants is strongly retained. By this regard the traditional
Pump & Treat approach could allow the removal of contaminants mostly from the more transmissive zones of
an aquifer but it has a negligible effect on the contaminant mass stored in low permeability media which are
released out slowly by back-diffusion. Moreover, coupling GCW with the continuous production of electron
donors should allow the enhancement of the biological reductive dechlorination inside the less permeable
layer thus potentially reducing the remediation time.
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