Nanotechnology has significant economic, health, and environmental benefits, including renewable energy and innovative environmental solutions. Manufactured nanoparticles have been incorporated into new materials and ...Nanotechnology has significant economic, health, and environmental benefits, including renewable energy and innovative environmental solutions. Manufactured nanoparticles have been incorporated into new materials and products because of their novel or enhanced properties. These very same properties also have prompted concerns about the potential environmental and human health hazard and risk posed by the manufactured nanomaterials. Appropriate risk management responses require the development of models capable of predicting the environmental and human health effects of the nanomaterials. Development of predictive models has been hampered by a lack of information concerning the environmental fate, behavior and effects of manufactured nanoparticles. The United Kingdom (UK) Environmental Nanoscience Initiative and the United States (US) Environmental Protection Agency have developed an international research program to enhance the knowledgebase and develop risk-predicting models for manufactured nanoparticles. Here we report selected highlights of the program as it sought to maximize the complementary strengths of the transatlantic scientific communities by funding three integrated US-UK consortia to investigate the transformation of these nanoparticles in terrestrial, aquatic, and atmospheric environment. Research results demonstrate there is a functional relationship between the physicochemical properties of environmentally transformed nanomaterials and their effects and that this relationship is amenable to modeling. In addition, the joint transatlantic program has allowed the leveraging of additional funding, promoting transboundary scientific collaboration.展开更多
The Environment Protection Agency Sierra Leone (EPA) is mandated by law to issue Environmental Impact Assessment license. Currently the agency achieves this mandate by issuing environmental licenses manually which alw...The Environment Protection Agency Sierra Leone (EPA) is mandated by law to issue Environmental Impact Assessment license. Currently the agency achieves this mandate by issuing environmental licenses manually which always encountered lot of problems of accountability and transparency of the management of environmental licenses and assessment documentation. Client’s information and documentation is usually mixed up while carrying files from one point to the other or from one staff to another. Data on client are stored in a way which makes it difficult for the management to retrieve useful information on time. This paper explores these challenges faced by the manual system of issuing environmental licenses and infer solutions to the current challenges by integrating a Geographic Information Systems (GIS) to develop an Environmental Cadastre administrative System (ECAS) which establishes a web-based information repository database developed with open sources software (Java, PHP, MySQL, QGIS) that published revenues online and made the data available to stakeholders and/or the public to complete the cycle of accountability and transparency. The information is presented and downloadable in a comprehensible and user-friendly manner, which in turn improves monitoring and reporting, and increases effectiveness and accountability of the management of environmental licenses and assessment documentation. The findings show these challenges facing the manual system, the back and forth between EPA and the client in the EIA process, the difficulty in the searching a client record, the mixing up of Client’s information and documentation by carrying files from one point to the other, and the storage of data on client in a way which makes it difficult for the management to retrieve useful information on time, and lack of back up when data or information is lost. Problems encountered in the time-consuming nature of the manual retrieval of files and preparation of prompt and accurate reports make it become a difficult task to accomplish as data and information are difficult to retrieve or collect from various files. Based on these findings, this paper provides the possible solution to the above problems. An online Environmental Cadastre administrative System (ECAS) which establishes a web-based information repository database was designed to capture the full lifecycle of environmental licenses including all stages of monitoring, licenses and payments and seamlessly manage the environmental impact assessment (EIA) licenses.展开更多
Concentrations of sixteen rare earth elements（REEs） in PM2.5 and potential-source samples, collected in Nanchang city in mid-September 2013, were determined by inductively coupled plasma mass spectrometry（ICP-MS）....Concentrations of sixteen rare earth elements（REEs） in PM2.5 and potential-source samples, collected in Nanchang city in mid-September 2013, were determined by inductively coupled plasma mass spectrometry（ICP-MS）. The results showed that the concentrations of total REEs（ΣREE） ranged from 78.76 to 1351 ng/mg. The order of REEs in PM2.5 samples showed the anthropogenic effects, Ce and Eu were affected more than the other REEs according to the enrichment factors. The results of chondrite-normalized REEs patterns and characteristic parameters showed evident light REEs fractionation, and positive anomalies of Ce and Eu in PM2.5. The other non-local pollution sources affected the PM2.5 samples, according to the triangular diagram of La, Ce and Sm compositions and plot of ΣREE vs δEu. Moreover, plot of（La/Sm）N vs（Gd/Yb）N revealed the effects of local sources. In conclusion, the REEs in potential-source samples were close to the background of local soil, while the REEs in PM2.5 samples in Nanchang city were jointly affected by the investigated local sources and other non-local sources.展开更多
With increasing environmental application,biochar(BC)will inevitably interact with and impact environmental behaviors of widely distributed extracellular DNA(eDNA),which however still remains to be studied.Herein,the ...With increasing environmental application,biochar(BC)will inevitably interact with and impact environmental behaviors of widely distributed extracellular DNA(eDNA),which however still remains to be studied.Herein,the adsorption/desorption and the degradation by nucleases of eDNA on three aromatized BCs pyrolyzed at 700℃were firstly investigated.The results show that the eDNA was irreversibly adsorbed by aromatized BCs and the pseudo-second-order and Freundlich models accurately described the adsorption process.Increasing solution ionic strength or decreasing pH below 5.0 significantly increased the eDNA adsorption on BCs.However,increasing pH from 5.0 to 10.0 faintly decreased eDNA adsorption.Electrostatic interaction,Ca ion bridge interaction,andπ-πinteraction between eDNA and BC could dominate the eDNA adsorption,while ligand exchange and hydrophobic interactions were minor contributors.The presence of BCs provided a certain protection to eDNA against degradation by DNase I.BC-bound eDNA could be partly degraded by nuclease,while BC-bound nuclease completely lost its degradability.These findings are of fundamental significance for the potential application of biochar in eDNA dissemination management and evaluating the environmental fate of eDNA.展开更多
The recent increasing use of γ-rays industrial computed tomography(γ-rays ICT) in various fields has induced greater attention to its performance as well as to considerations of radiation safety. It is understood th...The recent increasing use of γ-rays industrial computed tomography(γ-rays ICT) in various fields has induced greater attention to its performance as well as to considerations of radiation safety. It is understood that radiation protection planning cannot be sacrificed for the sake of CT image quality during the design, manufacture,and layout of γ-rays ICT systems. In the present work, we describe a typical γ-rays ICT system in brief, and, based on experience and pertinent examples, we propose design requirements for ensuring the radiation safety of the sealed radioactive source, source container, and workspace. The design examples and dose rate measurement results illustrate that the proposed design standards are reasonable,feasible, and safe, and are therefore meaningful for the design, manufacture, and layout of γ-rays ICT systems. This paper discussed the predominant measures associated with the radiation protection of γ-rays ICT systems in accordance with the pertinent Chinese standards. In addition, based on experience and pertinent examples, the design requirements for ensuring the radiation safety of a sealed radioactive source, source container, and workspace were defined in detail. The design examples and dose rate measurements conducted in conjunction with a γ-rays ICT system and workspace employing the proposed design standards have illustrated that the proposals provided in this paper are reasonable, feasible, and safe, and are therefore meaningful for the design, manufacture, and layout of γ-rays ICT systems.展开更多
Low levels (ng/g) of musk ketone (MK),used as a fragrance additive in the formulation of personal care products,are frequently detected in the water and other environment.Thus,aquatic organisms can be continuously exp...Low levels (ng/g) of musk ketone (MK),used as a fragrance additive in the formulation of personal care products,are frequently detected in the water and other environment.Thus,aquatic organisms can be continuously exposed to MK.In this study,kinetics and dose-response assessments of 2-amino-MK (AMK) metabolite,bound to cysteine-hemoglobin (Hb) in rainbow trout,formed by enzymatic nitro-reduction of MK have been demonstrated.Trout were exposed to a single exposure of 0.010,0.030,0.10,and 0.30 mg MK/g fish.Tw...展开更多
Ammoniated bagasse is a plant-derived organic sorbent that can be used for capturing oil and for supplying slow-release nutrients to oil-degrading microorganisms. We investigated the oil-wicking behavior of this sorbe...Ammoniated bagasse is a plant-derived organic sorbent that can be used for capturing oil and for supplying slow-release nutrients to oil-degrading microorganisms. We investigated the oil-wicking behavior of this sorbent under various conditions for its effectiveness in remediating oil-contaminated wetlands. Abiotic microcosms simulating a wetland environment were used to assess the influence of sand particle sizes （20x30 and 60x80 U.S. mesh）, degrees of oil saturation （25% and 75%）, water table levels （on top of the clean sand layer, oiled-sand layer, and sorbent layer）, and the presence of sorbent. Results indicated that oil wicking favors higher oil contamination, larger sand particle size, and low water coverage. Water coverage was the predominant factor limiting the effectiveness of sorbent. The most plausible explanation for this limitation was that sorbent captured more water than oil at higher water coverage.展开更多
This paper presents a case study for a complex contaminated groundwater site impacted by a historical release of chlorinated solvents in Silicon Valley, California. The original conceptual site model (CSM) inferred a ...This paper presents a case study for a complex contaminated groundwater site impacted by a historical release of chlorinated solvents in Silicon Valley, California. The original conceptual site model (CSM) inferred a contaminant migration pathway based on the groundwater gradient interpreted from groundwater elevation data, which is based on the underlying assumption that the subsurface conditions are homogeneous. However, the buried channel deposits render the underlying geology highly heterogeneous, and this heterogeneity plays a significant role in the subsurface migration of contaminants. Chemical fingerprinting evidence suggested that contamination at the downgradient property boundary was related to an off-site contaminant source. But, this alone was not a compelling argument. However, Environmental Sequence Stratigraphy (ESS), a geology-based environmental forensic technique, was applied to define the permeability architecture or the “plumbing” that controls subsurface fluid flow and contaminant migration. First, the geologic and depositional setting was synthesized based on regional geologic data, and representative facies models were identified for the site. Second, the existing CSM and site lithology data were reviewed and existing lithology data were graphically presented to display vertical grain-size patterns. This analysis focused on the nexus between the depositional environment and the site-specific subsurface data resulting in correlations/interpretations between and beyond data points that are based on established stratigraphic principles. The depositional environment results in buried river channels as the primary control on subsurface fluid flow, which defines hydrostratigraphic units (or HSUs). Finally, a hydrostratigraphic CSM that includes maps and cross sections was constructed to depict the HSUs present as a framework to integrate hydro-geology and chemistry data. This study demonstrates that: 1) Highly per-meable buried river channel deposits control subsurface fluid flow and contaminant transport, and have distinct chemical constituents and concentrations (i.e., they represent distinct HSUs), 2) Mapping of such HSUs is feasible with existing boring log data, 3) In settings such as the Santa Clara Valley where groundwater flow is governed by subsurface channel deposits, a hydrostratigraphic mapping approach is superior to a depth-based aquifer zonation approach, and 4) For heterogeneous subsurface, a detailed geology-based definition of the subsurface is an integral component of an environmental forensic analyses to determine contaminant source(s) and pathways.展开更多
Sixty springs of the Cuneo Province inland plains were sampled and analyzed for several chemical variables. Multi-variate analysis （PCA） of all the data was undertaken. The first principal component was positively c...Sixty springs of the Cuneo Province inland plains were sampled and analyzed for several chemical variables. Multi-variate analysis （PCA） of all the data was undertaken. The first principal component was positively correlated with chlorides, sulphites, hardness, and negatively correlated with altitude. The second principal component was positively correlated with DO and pH. Results showed that 4 groups of springs could be distinguished on the basis of environmental variables. A small number of springs did not group with the geographically more proximal springs but with another group due to a greater degree of affinity on the basis of the hydrochemical variables.展开更多
Baseline Environmental Impact Assessment (EIA) of mining projects in Sierra Leone creates a challenging environment for data collection and impact prediction. Application of geographic information systems provides sui...Baseline Environmental Impact Assessment (EIA) of mining projects in Sierra Leone creates a challenging environment for data collection and impact prediction. Application of geographic information systems provides suitable spatial analysis data collection methods to reduce the challenges created by mining environments. This research develops a baseline spatial geodatabase template for evaluating potential and predicted environmental impacts assessment of mining projects in Sierra Leone. It is observed that spatial analysis of impacts of mining projects on the environmental attributes, especially air, noise, water, land, and socio-economy in mining areas is largely unexplored in Sierra Leone. The literature review revealed that no complete GIS spatial data geodatabase collection template appears to have been developed to date to provide an integrated sustainable spatial analysis and modelling tool for EIA and environmental management of mining in Sierra Leone. Therefore developing a Geographic Information Systems baseline geodatabase template for the evaluation of potential and predicted environmental impact for sustainable environmental impact assessment of mining in Sierra Leone will: 1) provide support to the data acquisition process of environmental impact assessment, 2) offer a concept for developing analysis methods for environmental management of mining, 3) minimize the undesired environmental impacts of mining, and 4) give an optimal proposal for data collection and analysis of mining industry in attaining sustainable development in Sierra Leone. Due to the limited available data, a conceptual GIS database template has been developed rather than a database case study of a mining site. No site investigation and data collection were undertaken. The geospatial database template was designed using ArcCatalog, ArcGIS 10.7.1. software, through the following steps: exploration of the general data requirement of environmental impact assessment studies of mining, the definition of the general baseline datasets requirement of environmental impact assessment in mining, structuring of the environmental impact assessment baseline spatial geodatabase, creating the geographic geodatabase dictionary, selecting, matching geographic data with geodatabase structure, designing the feature class and attributes, creating the baseline GIS geodatabase template. The GIS spatial geodatabase template has several advantages for environmental impact assessment of mining including avoiding data redundancy, integrating data into a single database, creating uniformity in data collection, easy to find and track data, integrated spatial and non-spatial data, and reducing the volume of data.展开更多
Linking meteorology and air pollutants is a key challenge.The study investigated meteorological effects on PM_(2.5)concentration using the advanced convergent cross mapping method,utilizing hourly PM_(2.5)concentratio...Linking meteorology and air pollutants is a key challenge.The study investigated meteorological effects on PM_(2.5)concentration using the advanced convergent cross mapping method,utilizing hourly PM_(2.5)concentration and six meteorological factors across eight provinces and cities in Vietnam.Results demonstrated that temperature(ρ=0.30)and radiation(ρ=0.30)produced the highest effects,followed by humidity(ρ=0.28)and wind speed(ρ=0.24),while pressure(ρ=0.22)and wind direction(ρ=0.17)produced the weakest effects on PM_(2.5)concentration.Comparing theρvalues showed that temperature,wind speed,and wind direction had greater impacts on PM_(2.5)concentration during the dry season whereas radiation had a more influence during the wet season;Southern stations experienced larger meteorological effects.Temperature,humidity,pressure,and wind direction had both positive and negative influences on PM_(2.5)concentration,while radiation and wind speed mostly had negative influences.During PM_(2.5)pollution episodes,there wasmore contribution ofmeteorological effects on PM_(2.5)concentration indicated byρvalues.At contaminated levels,humidity(ρ=0.45)was the most dominant factor affecting PM_(2.5)concentration,followed by temperature(ρ=0.41)and radiation(ρ=0.40).Pollution episodes were pointed out to be more prevalent under higher humidity,higher pressure,lower temperature,lower radiation,and lower wind speed.Theρcalculation also revealed that lower temperature,lower radiation,and higher humidity greatly accelerated each other under pollution episodes,further enhancing PM_(2.5)concentration.The findings contributed to the literature on meteorology and air pollution interaction.展开更多
Previously, we showed that prophylactic addition of glucose to Harsha Lake water samples could inhibit cyanobacteria growth, at least for a short period of time. The current study tested cyanobacterial control with gl...Previously, we showed that prophylactic addition of glucose to Harsha Lake water samples could inhibit cyanobacteria growth, at least for a short period of time. The current study tested cyanobacterial control with glucose for the entire Harsha Lake bloom season. Water samples (1000 ml) were collected weekly from Harsha Lake during the algal-bloom season starting June 9 and lasting until August 24, 2022. To each of two 7-liter polypropylene containers, 500 ml of Harsha Lake water was added, and the containers were placed in a controlled environment chamber. To one container labeled “Treated,” 0.15 g of glucose was added, and nothing was added to the container labeled “Control.” After that, three 25 ml samples from each container were collected and used for 16S rRNA gene sequencing each week. Then 1000 ml of Harsha Lake water was newly collected each week, with 500 ml added to each container, along with the addition of 0.15 g glucose to the “Treated” container. Sequencing data were used to examine differences in the composition of bacterial communities between Treated and Control containers. Treatment with glucose altered the microbial communities by 1) reducing taxonomic diversity, 2) largely eliminating cyanobacterial taxa, and 3) increasing the relative abundance of subsets of non-cyanobacterial taxa (such as Proteobacteria and Actinobacteriota). These effects were observed across time despite weekly inputs derived directly from Lake water. The addition of glucose to a container receiving weekly additions of Lake water suppressed the cyanobacterial populations during the entire summer bloom season. The glucose appears to stimulate the diversity of certain bacterial taxa at the expense of the cyanobacteria.展开更多
To investigate the effect of neodymium （Nd） on Microcystis aeruginosa, the growth and physiological changes were studied by lab cultured experiments. The results showed that the content of chlorophyll a （Chl-a）, s...To investigate the effect of neodymium （Nd） on Microcystis aeruginosa, the growth and physiological changes were studied by lab cultured experiments. The results showed that the content of chlorophyll a （Chl-a）, soluble protein and the activity of superoxide dismutase （SOD）, peroxidase （POD）, and catalase （CAT） increased compared with the control （Nd3＋-free）, and the growth of M. aeruginosa was stimulated in the treatments of initial Nd3＋ concentration ≤1 mg/L; while the treatments of initial Nd3＋ concentration was in the range of 5.00–10.00 mg/L, the content of malondiadehyde （MDA） increased immediately but the activity of CAT reduced, which resulted in weakened M. aeruginosa’s ability to eliminate the active oxygen and the ruin of antioxidant defense system, and stunting the growth of M. aeruginosa. With the initial Nd3＋ concentration of 50 mg/L, the growth of M. aeruginosa was totally stunted. The ultrastructure showed that excess Nd3＋ could lead to the decrease of thylakoid and the increase of fat particle in cells of M. aeruginosa, and the cell membrane became rough and even broken, causing an irreversible damage to algal cells.展开更多
文摘Nanotechnology has significant economic, health, and environmental benefits, including renewable energy and innovative environmental solutions. Manufactured nanoparticles have been incorporated into new materials and products because of their novel or enhanced properties. These very same properties also have prompted concerns about the potential environmental and human health hazard and risk posed by the manufactured nanomaterials. Appropriate risk management responses require the development of models capable of predicting the environmental and human health effects of the nanomaterials. Development of predictive models has been hampered by a lack of information concerning the environmental fate, behavior and effects of manufactured nanoparticles. The United Kingdom (UK) Environmental Nanoscience Initiative and the United States (US) Environmental Protection Agency have developed an international research program to enhance the knowledgebase and develop risk-predicting models for manufactured nanoparticles. Here we report selected highlights of the program as it sought to maximize the complementary strengths of the transatlantic scientific communities by funding three integrated US-UK consortia to investigate the transformation of these nanoparticles in terrestrial, aquatic, and atmospheric environment. Research results demonstrate there is a functional relationship between the physicochemical properties of environmentally transformed nanomaterials and their effects and that this relationship is amenable to modeling. In addition, the joint transatlantic program has allowed the leveraging of additional funding, promoting transboundary scientific collaboration.
文摘The Environment Protection Agency Sierra Leone (EPA) is mandated by law to issue Environmental Impact Assessment license. Currently the agency achieves this mandate by issuing environmental licenses manually which always encountered lot of problems of accountability and transparency of the management of environmental licenses and assessment documentation. Client’s information and documentation is usually mixed up while carrying files from one point to the other or from one staff to another. Data on client are stored in a way which makes it difficult for the management to retrieve useful information on time. This paper explores these challenges faced by the manual system of issuing environmental licenses and infer solutions to the current challenges by integrating a Geographic Information Systems (GIS) to develop an Environmental Cadastre administrative System (ECAS) which establishes a web-based information repository database developed with open sources software (Java, PHP, MySQL, QGIS) that published revenues online and made the data available to stakeholders and/or the public to complete the cycle of accountability and transparency. The information is presented and downloadable in a comprehensible and user-friendly manner, which in turn improves monitoring and reporting, and increases effectiveness and accountability of the management of environmental licenses and assessment documentation. The findings show these challenges facing the manual system, the back and forth between EPA and the client in the EIA process, the difficulty in the searching a client record, the mixing up of Client’s information and documentation by carrying files from one point to the other, and the storage of data on client in a way which makes it difficult for the management to retrieve useful information on time, and lack of back up when data or information is lost. Problems encountered in the time-consuming nature of the manual retrieval of files and preparation of prompt and accurate reports make it become a difficult task to accomplish as data and information are difficult to retrieve or collect from various files. Based on these findings, this paper provides the possible solution to the above problems. An online Environmental Cadastre administrative System (ECAS) which establishes a web-based information repository database was designed to capture the full lifecycle of environmental licenses including all stages of monitoring, licenses and payments and seamlessly manage the environmental impact assessment (EIA) licenses.
基金Project supported by the National Natural Science Foundation of China(21477042,21377042)the Natural Science Foundation of Fujian Province(2016J01065)
文摘Concentrations of sixteen rare earth elements（REEs） in PM2.5 and potential-source samples, collected in Nanchang city in mid-September 2013, were determined by inductively coupled plasma mass spectrometry（ICP-MS）. The results showed that the concentrations of total REEs（ΣREE） ranged from 78.76 to 1351 ng/mg. The order of REEs in PM2.5 samples showed the anthropogenic effects, Ce and Eu were affected more than the other REEs according to the enrichment factors. The results of chondrite-normalized REEs patterns and characteristic parameters showed evident light REEs fractionation, and positive anomalies of Ce and Eu in PM2.5. The other non-local pollution sources affected the PM2.5 samples, according to the triangular diagram of La, Ce and Sm compositions and plot of ΣREE vs δEu. Moreover, plot of（La/Sm）N vs（Gd/Yb）N revealed the effects of local sources. In conclusion, the REEs in potential-source samples were close to the background of local soil, while the REEs in PM2.5 samples in Nanchang city were jointly affected by the investigated local sources and other non-local sources.
基金supported by the National Natural Science Foundation of China(Nos.21976158,21525728,and 21677129)。
文摘With increasing environmental application,biochar(BC)will inevitably interact with and impact environmental behaviors of widely distributed extracellular DNA(eDNA),which however still remains to be studied.Herein,the adsorption/desorption and the degradation by nucleases of eDNA on three aromatized BCs pyrolyzed at 700℃were firstly investigated.The results show that the eDNA was irreversibly adsorbed by aromatized BCs and the pseudo-second-order and Freundlich models accurately described the adsorption process.Increasing solution ionic strength or decreasing pH below 5.0 significantly increased the eDNA adsorption on BCs.However,increasing pH from 5.0 to 10.0 faintly decreased eDNA adsorption.Electrostatic interaction,Ca ion bridge interaction,andπ-πinteraction between eDNA and BC could dominate the eDNA adsorption,while ligand exchange and hydrophobic interactions were minor contributors.The presence of BCs provided a certain protection to eDNA against degradation by DNase I.BC-bound eDNA could be partly degraded by nuclease,while BC-bound nuclease completely lost its degradability.These findings are of fundamental significance for the potential application of biochar in eDNA dissemination management and evaluating the environmental fate of eDNA.
文摘The recent increasing use of γ-rays industrial computed tomography(γ-rays ICT) in various fields has induced greater attention to its performance as well as to considerations of radiation safety. It is understood that radiation protection planning cannot be sacrificed for the sake of CT image quality during the design, manufacture,and layout of γ-rays ICT systems. In the present work, we describe a typical γ-rays ICT system in brief, and, based on experience and pertinent examples, we propose design requirements for ensuring the radiation safety of the sealed radioactive source, source container, and workspace. The design examples and dose rate measurement results illustrate that the proposed design standards are reasonable,feasible, and safe, and are therefore meaningful for the design, manufacture, and layout of γ-rays ICT systems. This paper discussed the predominant measures associated with the radiation protection of γ-rays ICT systems in accordance with the pertinent Chinese standards. In addition, based on experience and pertinent examples, the design requirements for ensuring the radiation safety of a sealed radioactive source, source container, and workspace were defined in detail. The design examples and dose rate measurements conducted in conjunction with a γ-rays ICT system and workspace employing the proposed design standards have illustrated that the proposals provided in this paper are reasonable, feasible, and safe, and are therefore meaningful for the design, manufacture, and layout of γ-rays ICT systems.
文摘Low levels (ng/g) of musk ketone (MK),used as a fragrance additive in the formulation of personal care products,are frequently detected in the water and other environment.Thus,aquatic organisms can be continuously exposed to MK.In this study,kinetics and dose-response assessments of 2-amino-MK (AMK) metabolite,bound to cysteine-hemoglobin (Hb) in rainbow trout,formed by enzymatic nitro-reduction of MK have been demonstrated.Trout were exposed to a single exposure of 0.010,0.030,0.10,and 0.30 mg MK/g fish.Tw...
基金funding was provided by the U.S. Environmental Protection Agency under EP-C-05-056,WA 1-17
文摘Ammoniated bagasse is a plant-derived organic sorbent that can be used for capturing oil and for supplying slow-release nutrients to oil-degrading microorganisms. We investigated the oil-wicking behavior of this sorbent under various conditions for its effectiveness in remediating oil-contaminated wetlands. Abiotic microcosms simulating a wetland environment were used to assess the influence of sand particle sizes （20x30 and 60x80 U.S. mesh）, degrees of oil saturation （25% and 75%）, water table levels （on top of the clean sand layer, oiled-sand layer, and sorbent layer）, and the presence of sorbent. Results indicated that oil wicking favors higher oil contamination, larger sand particle size, and low water coverage. Water coverage was the predominant factor limiting the effectiveness of sorbent. The most plausible explanation for this limitation was that sorbent captured more water than oil at higher water coverage.
文摘This paper presents a case study for a complex contaminated groundwater site impacted by a historical release of chlorinated solvents in Silicon Valley, California. The original conceptual site model (CSM) inferred a contaminant migration pathway based on the groundwater gradient interpreted from groundwater elevation data, which is based on the underlying assumption that the subsurface conditions are homogeneous. However, the buried channel deposits render the underlying geology highly heterogeneous, and this heterogeneity plays a significant role in the subsurface migration of contaminants. Chemical fingerprinting evidence suggested that contamination at the downgradient property boundary was related to an off-site contaminant source. But, this alone was not a compelling argument. However, Environmental Sequence Stratigraphy (ESS), a geology-based environmental forensic technique, was applied to define the permeability architecture or the “plumbing” that controls subsurface fluid flow and contaminant migration. First, the geologic and depositional setting was synthesized based on regional geologic data, and representative facies models were identified for the site. Second, the existing CSM and site lithology data were reviewed and existing lithology data were graphically presented to display vertical grain-size patterns. This analysis focused on the nexus between the depositional environment and the site-specific subsurface data resulting in correlations/interpretations between and beyond data points that are based on established stratigraphic principles. The depositional environment results in buried river channels as the primary control on subsurface fluid flow, which defines hydrostratigraphic units (or HSUs). Finally, a hydrostratigraphic CSM that includes maps and cross sections was constructed to depict the HSUs present as a framework to integrate hydro-geology and chemistry data. This study demonstrates that: 1) Highly per-meable buried river channel deposits control subsurface fluid flow and contaminant transport, and have distinct chemical constituents and concentrations (i.e., they represent distinct HSUs), 2) Mapping of such HSUs is feasible with existing boring log data, 3) In settings such as the Santa Clara Valley where groundwater flow is governed by subsurface channel deposits, a hydrostratigraphic mapping approach is superior to a depth-based aquifer zonation approach, and 4) For heterogeneous subsurface, a detailed geology-based definition of the subsurface is an integral component of an environmental forensic analyses to determine contaminant source(s) and pathways.
文摘Sixty springs of the Cuneo Province inland plains were sampled and analyzed for several chemical variables. Multi-variate analysis （PCA） of all the data was undertaken. The first principal component was positively correlated with chlorides, sulphites, hardness, and negatively correlated with altitude. The second principal component was positively correlated with DO and pH. Results showed that 4 groups of springs could be distinguished on the basis of environmental variables. A small number of springs did not group with the geographically more proximal springs but with another group due to a greater degree of affinity on the basis of the hydrochemical variables.
文摘Baseline Environmental Impact Assessment (EIA) of mining projects in Sierra Leone creates a challenging environment for data collection and impact prediction. Application of geographic information systems provides suitable spatial analysis data collection methods to reduce the challenges created by mining environments. This research develops a baseline spatial geodatabase template for evaluating potential and predicted environmental impacts assessment of mining projects in Sierra Leone. It is observed that spatial analysis of impacts of mining projects on the environmental attributes, especially air, noise, water, land, and socio-economy in mining areas is largely unexplored in Sierra Leone. The literature review revealed that no complete GIS spatial data geodatabase collection template appears to have been developed to date to provide an integrated sustainable spatial analysis and modelling tool for EIA and environmental management of mining in Sierra Leone. Therefore developing a Geographic Information Systems baseline geodatabase template for the evaluation of potential and predicted environmental impact for sustainable environmental impact assessment of mining in Sierra Leone will: 1) provide support to the data acquisition process of environmental impact assessment, 2) offer a concept for developing analysis methods for environmental management of mining, 3) minimize the undesired environmental impacts of mining, and 4) give an optimal proposal for data collection and analysis of mining industry in attaining sustainable development in Sierra Leone. Due to the limited available data, a conceptual GIS database template has been developed rather than a database case study of a mining site. No site investigation and data collection were undertaken. The geospatial database template was designed using ArcCatalog, ArcGIS 10.7.1. software, through the following steps: exploration of the general data requirement of environmental impact assessment studies of mining, the definition of the general baseline datasets requirement of environmental impact assessment in mining, structuring of the environmental impact assessment baseline spatial geodatabase, creating the geographic geodatabase dictionary, selecting, matching geographic data with geodatabase structure, designing the feature class and attributes, creating the baseline GIS geodatabase template. The GIS spatial geodatabase template has several advantages for environmental impact assessment of mining including avoiding data redundancy, integrating data into a single database, creating uniformity in data collection, easy to find and track data, integrated spatial and non-spatial data, and reducing the volume of data.
文摘Linking meteorology and air pollutants is a key challenge.The study investigated meteorological effects on PM_(2.5)concentration using the advanced convergent cross mapping method,utilizing hourly PM_(2.5)concentration and six meteorological factors across eight provinces and cities in Vietnam.Results demonstrated that temperature(ρ=0.30)and radiation(ρ=0.30)produced the highest effects,followed by humidity(ρ=0.28)and wind speed(ρ=0.24),while pressure(ρ=0.22)and wind direction(ρ=0.17)produced the weakest effects on PM_(2.5)concentration.Comparing theρvalues showed that temperature,wind speed,and wind direction had greater impacts on PM_(2.5)concentration during the dry season whereas radiation had a more influence during the wet season;Southern stations experienced larger meteorological effects.Temperature,humidity,pressure,and wind direction had both positive and negative influences on PM_(2.5)concentration,while radiation and wind speed mostly had negative influences.During PM_(2.5)pollution episodes,there wasmore contribution ofmeteorological effects on PM_(2.5)concentration indicated byρvalues.At contaminated levels,humidity(ρ=0.45)was the most dominant factor affecting PM_(2.5)concentration,followed by temperature(ρ=0.41)and radiation(ρ=0.40).Pollution episodes were pointed out to be more prevalent under higher humidity,higher pressure,lower temperature,lower radiation,and lower wind speed.Theρcalculation also revealed that lower temperature,lower radiation,and higher humidity greatly accelerated each other under pollution episodes,further enhancing PM_(2.5)concentration.The findings contributed to the literature on meteorology and air pollution interaction.
文摘Previously, we showed that prophylactic addition of glucose to Harsha Lake water samples could inhibit cyanobacteria growth, at least for a short period of time. The current study tested cyanobacterial control with glucose for the entire Harsha Lake bloom season. Water samples (1000 ml) were collected weekly from Harsha Lake during the algal-bloom season starting June 9 and lasting until August 24, 2022. To each of two 7-liter polypropylene containers, 500 ml of Harsha Lake water was added, and the containers were placed in a controlled environment chamber. To one container labeled “Treated,” 0.15 g of glucose was added, and nothing was added to the container labeled “Control.” After that, three 25 ml samples from each container were collected and used for 16S rRNA gene sequencing each week. Then 1000 ml of Harsha Lake water was newly collected each week, with 500 ml added to each container, along with the addition of 0.15 g glucose to the “Treated” container. Sequencing data were used to examine differences in the composition of bacterial communities between Treated and Control containers. Treatment with glucose altered the microbial communities by 1) reducing taxonomic diversity, 2) largely eliminating cyanobacterial taxa, and 3) increasing the relative abundance of subsets of non-cyanobacterial taxa (such as Proteobacteria and Actinobacteriota). These effects were observed across time despite weekly inputs derived directly from Lake water. The addition of glucose to a container receiving weekly additions of Lake water suppressed the cyanobacterial populations during the entire summer bloom season. The glucose appears to stimulate the diversity of certain bacterial taxa at the expense of the cyanobacteria.
基金supported by Educational Commission of Sichuan Province of China (10ZA059)Innovation Programme of College Students of China (01409207)
文摘To investigate the effect of neodymium （Nd） on Microcystis aeruginosa, the growth and physiological changes were studied by lab cultured experiments. The results showed that the content of chlorophyll a （Chl-a）, soluble protein and the activity of superoxide dismutase （SOD）, peroxidase （POD）, and catalase （CAT） increased compared with the control （Nd3＋-free）, and the growth of M. aeruginosa was stimulated in the treatments of initial Nd3＋ concentration ≤1 mg/L; while the treatments of initial Nd3＋ concentration was in the range of 5.00–10.00 mg/L, the content of malondiadehyde （MDA） increased immediately but the activity of CAT reduced, which resulted in weakened M. aeruginosa’s ability to eliminate the active oxygen and the ruin of antioxidant defense system, and stunting the growth of M. aeruginosa. With the initial Nd3＋ concentration of 50 mg/L, the growth of M. aeruginosa was totally stunted. The ultrastructure showed that excess Nd3＋ could lead to the decrease of thylakoid and the increase of fat particle in cells of M. aeruginosa, and the cell membrane became rough and even broken, causing an irreversible damage to algal cells.
