Objective:Previous studies have demonstrated that the metals cadmium and arsenic exhibit estrogen-like effects and may influence the occurrence and development of gynecological tumors.This study aims to explore the as...Objective:Previous studies have demonstrated that the metals cadmium and arsenic exhibit estrogen-like effects and may influence the occurrence and development of gynecological tumors.This study aims to explore the association between urinary cadmium and arsenic levels and the prevalence of gynecologic cancers using data from the National Health and Nutrition Examination Survey(NHANES).Methods:Data from female participants in NHANES 2003—2018 were analyzed.Using R software,datasets(DEMO,BMX,etc.)were merged,and complete cases were retained by intersecting row names,yielding a total of 2999 participants.After applying strict exclusion criteria,2802 participants were included:83 with gynecologic cancer(cancer group)and 2719 without(control group).Demographic,reproductive health,and urinary cadmium and arsenic data were collected.Binary Logistic regression models were employed to assess associations between urinary cadmium and arsenic levels and gynecologic cancer risk.Results:High urinary cadmium and arsenic levels were risk factors for gynecologic cancers,with odds ratios(ORs)of 1.623(95%CI 1.217 to 2.166)and 1.003(95%CI 1.001 to 1.005),respectively.After propensity score matching(PSM),the trend remained;cadmium was still a statistically significant risk factor with an OR of 2.182(95%CI 1.343 to 3.545),while arsenic’s association,though not statistically significant,still trended toward risk(OR=1.004,95%CI 0.999 to 1.009).Subgroup analyses showed that both cadmium and arsenic were risk factors for ovarian cancer(OR=1.745,95%CI 1.178 to 2.586 and OR=1.005,95%CI 1.002 to 1.008,respectively);these associations persisted after PSM.Additionally,cadmium increased the risk of endometrial cancer(OR=1.617,95%CI 1.109 to 2.356).Conclusion:Exposure to cadmium and arsenic is associated with an increased risk of ovarian and endometrial cancers.These findings suggest that reducing environmental exposure to heavy metals such as cadmium and arsenic may help prevent certain gynecologic cancers.展开更多
Copper is a strategic metal that plays an important role in many industries.In copper metallurgy,electrolytic refining is essential to obtain high-purity copper.However,during the electrolytic refining process,impurit...Copper is a strategic metal that plays an important role in many industries.In copper metallurgy,electrolytic refining is essential to obtain high-purity copper.However,during the electrolytic refining process,impurities such as arsenic are introduced into the electrolyte,which significantly affect the subsequent production and quality of copper products.This paper first discusses the sources,forms,and transformation pathways of arsenic in copper electrolyte during the electrolytic process,then reviews various arsenic removal technologies in detail,including electrowinning,adsorption,solvent extraction,ion exchange,membrane filtration,and precipitation.Particular emphasis is placed on electrowinning,which is the most widely used and mature among these arsenic removal techniques.The paper evaluates these methods based on arsenic removal efficiency,cost effectiveness,technical maturity,environmental friendliness,and operation simplicity.In addition,the paper explores future trends in copper electrolyte purification,focusing on waste reduction at source,resource utilization,intelligent digitalization,and innovations in materials and processes.This review aims to provide researchers and practitioners with a comprehensive and in-depth reference on arsenic removal methods in copper electrolytes.展开更多
Massive amounts of low-grade tin middlings have been produced from tin tailings,in which arsenic and tin are worthy to be recycled.Owing to high sulfur content in these tin middlings,a novel self-sulfurization roastin...Massive amounts of low-grade tin middlings have been produced from tin tailings,in which arsenic and tin are worthy to be recycled.Owing to high sulfur content in these tin middlings,a novel self-sulfurization roasting was proposed to transform,separate and recover arsenic and tin in this research.There was no extra curing agent to be added,which decreased the formation of pollutant S-containing gas.The self-sulfurization process involved a two-stage roasting of reduction followed by sulfurization.First in reduction roasting,FeAsS decomposed to FeS and As and the As then transformed to As_(4)(g)and As_(4)S_(4)(g),via which the arsenic was separated and recovered.The arsenic content in the first residue could be decreased to 0.72 wt.%.Accompanied with it,the FeS was firstly oxidized to Fe_(1−x)S and then to SO_(2)(g)by the coexisted Fe_(2)O_(3),and finally reduced and combined with the independent Fe_(2)O_(3)to form Fe_(1−x)S.In the followed sulfurization roasting,the Fe_(1−x)S sulfurized SnO_(2)to SnS(g),due to which tin could be recovered and its content in the second residue decreased to 0.01 wt.%.This study provided an efficient method to separate and recover arsenic and tin from low-grade tin middlings.展开更多
A process was proposed to convert and separate selenium and arsenic in copper anode slime(CAS) by low-temperature alkali fusion process.Central composite design was employed to optimize the effective parameters,in whi...A process was proposed to convert and separate selenium and arsenic in copper anode slime(CAS) by low-temperature alkali fusion process.Central composite design was employed to optimize the effective parameters,in which Na OH/CAS mass ratio,fusion temperature and fusion time were selected as variables,and the conversion ratio of selenium and arsenic as responses.Second-order polynomial models of high significance and 3D response surface plots were constructed to show the relationship between the responses and the variables.Optimum area of >90% selenium conversion ratio and >90% arsenic conversion ratio was obtained by the overlaid contours at Na OH/CAS mass ratio of 0.65-0.75,fusion temperature of 803-823 K and fusion time of 20-30 min.The models are validated by experiments in the optimum area,and the results demonstrate that these models are reliable and accurate in predicting the fusion process.展开更多
Iron-modified biochar(FeOS)is known to be effective at immobilization of arsenic(As)in soils.A pot experiment was conducted to investigate the effects of FeOS on As availability and ttransportation in the soil-rice sy...Iron-modified biochar(FeOS)is known to be effective at immobilization of arsenic(As)in soils.A pot experiment was conducted to investigate the effects of FeOS on As availability and ttransportation in the soil-rice system at different growth stages of rice with different pollution levels.The results showed that Fe concentration decreased and As concentration increased in paddy soils with the FeOS addition,especially in 120 mg/kg As treatment,the As concentration decreased by 16.46%and 30.56%at the maturity stage with 0.5%and 1%FeOS additions,respectively.Compared with the control,the application of FeOS reduced the arsenic content in rice tissues and increased the biomass,with the root biomass increased by 12.68%and the shoot biomass was increased by 8.94%with the addition of 1%FeOS.This may be related to the promotion of iron plaque formation and the transformation of microbial community structure in FeOS treatments,in accordance with the result of gene abundance and Fe/As contents of iron plaque in the study.This study is expected to provide further support and theoretical basis for the application of FeOS in the remediation of As contaminated paddy soil.展开更多
Water leaching of As2O3 from metallurgical dust containing various metals was investigated,serving the purpose of dearsenization and simultaneous metal enrichment especially for indium.Effects of leaching temperature,...Water leaching of As2O3 from metallurgical dust containing various metals was investigated,serving the purpose of dearsenization and simultaneous metal enrichment especially for indium.Effects of leaching temperature,liquid/solid ratio(LSR)and leaching time were studied.It was found that the initial dissolution was very fast but was then so inhibited by the increasingly dissolved As2O3,which makes it difficult to saturate enough arsenic in the leaching solution or in leaching out all the soluble arsenic with excess dosage of water within acceptable time(120 min).Only about 73%of As2O3 was extracted under the optimal conditions investigated.Two-step leaching showed similar trends and was thus unnecessary for improving As2O3 extraction.These observations could reasonably be accounted for the reversibility of the dissolution reaction.Kinetically,the leaching was described satisfactorily by the semi-empirical Avrami model with the apparent activation energy of 36.08 kJ/mol.The purity of the obtained product As2O3 could reach 98.7%,while the indium could be enriched in the leaching residue without loss.展开更多
Bibliometrics is an important branch in the field of information science,and it is widely used in many disciplines in modern research.A current active research subject can be analyzed and summarized from many aspects,...Bibliometrics is an important branch in the field of information science,and it is widely used in many disciplines in modern research.A current active research subject can be analyzed and summarized from many aspects,such as the core institutions,core authors,highly cited papers,and keywords by using bibliometrics.This paper describes a bibliometric analysis regarding soil arsenic content by using the database from Web of Science to compare relevant research from work done domestically and abroad from 2005 to 2016.The results show that the relevant publications in China and overseas both dramatically increased from 2009,which indicates that research activity is expanding.The USA produced 27.3%of all relevant articles followed by China with 26.9%and India with 9.5%.Key issues mainly focused on agriculture and environmental science.Major journals studied include the following:Science of the Total Environment,Environmental and Experimental Botany,Environmental Pollution,Chemosphere,Journal of Hazardous Materials,Journal of Environmental Chemical Engineering,Journal of Geochemical Exploration,Ecotoxicology and Environmental Safety,Environmental Research,Talanta,and Applied Geochemistry.These are the most important journals in this field.In light of cooperation between countries,it is clear that China and the United States occupy the leading position.展开更多
Objective To observe the apoptosis of osteosarcoma MG-63 cells induced by As2O3 and to explore its possible mechanisms. Methods The flowcytometric analysis and transmission electronmicroscope were performed to investi...Objective To observe the apoptosis of osteosarcoma MG-63 cells induced by As2O3 and to explore its possible mechanisms. Methods The flowcytometric analysis and transmission electronmicroscope were performed to investigate the inducing apoptosis and inhibitative of As2O3 on osteosarcoma MG-63 cells. In order to study mechanism of apoptosis in MG-63 cells treated with As2 O3, microarray was performed. The down-regulated gene was confirmed by RT-PCR, Northern-blotting. Results After treated with As2O3, hypodiploid peak before G0/G1 phase was observed in MG-63 cells through FCM analysis. Loss of microvilli, condensation and fragmentation of nuclear chromatin, condensation of cytoplasmic organelles, dilatation of the endoplasmic reticulum shrinkage of cells and alterations in cell membranes and apoptosis bodies which were observed in MG-63 cells treated with As2O3 by transmission electronmicroscope. The results of microarray show that As2 O3 induced MG-63 cell apoptosis involves down-regulation of IEX-1 and the down-regulated gene is confirmed by RT-PCR and Northern-blotting.Conclusion The results show that As2 O3 selectively inhibits growth of the solid tumor MG-63 cells by triggering apoptosis and indicates MG-63 induced by As2O3 cell apoptosis may through the IEX-1 pathway.展开更多
Quorum sensing is one kind of cell-to-cell signalling system among microorganisms that works in response to their population density via autoinducers exemplified by AHL and oligopeptides. In this study, fourteen AHL d...Quorum sensing is one kind of cell-to-cell signalling system among microorganisms that works in response to their population density via autoinducers exemplified by AHL and oligopeptides. In this study, fourteen AHL derivatives were synthesised by a chemical synthesis method, and two types of AHL derivatives were measured and screened by crystal violet staining assay, which have more obvious inhibitory effects on A. ferrooxidans biofilms under arsenic environment. Their structures were verified through IR and NMR identification. The morphological changes of A. ferrooxidans under the influence of the AHL derivatives were compared. In addition, the effects of AHL derivatives(0.1 μg/mL and 1 μg/mL) on membrane formation of A. ferrooxidans under high concentration of arsenic resistance(1,600 mg/L) were explored. Solid experimental data firstly showed that a portion of logarithmic microorganisms were ruptured under the effect of high arsenic concentration. Secondly, the volume of the cell shrank and the number of extracellular polymeric substances decreased after the addition of the AHL derivatives at high concentrations. Therefore, we found here that two derivatives used at concentrations of 0.1 μg/mL and 1 μg/m L accompanied with high concentration of arsenic can both effectively restrict biofilms formation by A. ferrooxidans.展开更多
A field study was conducted to determine the behavior and distribution of arsenic during the pyrometallurgy process in a typical SKS(Shuikoushan) lead smelter in Hunan province, China. Environmental influences of arse...A field study was conducted to determine the behavior and distribution of arsenic during the pyrometallurgy process in a typical SKS(Shuikoushan) lead smelter in Hunan province, China. Environmental influences of arsenic in selected samples were evaluated. Arsenic contents in all input and output samples vary from 0.11% in raw lead to 6.66% in collected dust-2. More arsenic is volatilized in blast furnace and fuming furnace(73.02% of arsenic input) than bottom blowing furnace(10.29% of arsenic input).There are 78.97%, 13.69%, 7.31% of total arsenic distributed in intermediate materials, stockpiled materials and unorganized emissions, respectively. Matte slag-2, collected dust-1 and secondary zinc oxide are hazardous based on the arsenic concentrations of toxicity characteristic leaching procedure. According to risk assessment code(RAC) guideline, arsenic in collected dust-1 poses a very serious risk to the surrounding environment, arsenic in speiss, matte slag-2, water-quenched slag and secondary zinc oxide show low risk, while arsenic in matte slag-1, collected dust-2 and post dust has no risk to the environment.展开更多
A refractory gold concentrate with 19% arsenic was treated by a mixed moderately thermophiles in an airlift bioreactor through an adaptation protocol. The moderately thermophiles could respond well to 20%(w/v) pulp de...A refractory gold concentrate with 19% arsenic was treated by a mixed moderately thermophiles in an airlift bioreactor through an adaptation protocol. The moderately thermophiles could respond well to 20%(w/v) pulp density with less than 10% loss of productivity, and resist arsenic up to 15 g/L. There were a lot of jarosite, arsenolite and sulfur, but not scorodite and ferric arsenate in the bioleached residue. Jarosite passivation and lower sulfur-oxidizing activity of the cells due to the toxicity of the high concentrations of soluble arsenic and iron ions at low p H value should mainly response for the incomplete extraction at high pulp density. The initial bacterial community did not change in nature except for new found P aeruginosa ANSC, but sulfur-oxidizing microorganisms have been dominant microorganisms after a long time of adaptation. Pseudomonas aeruginosa originating from the gold concentrate should be closely relative to the metabolism of the organic matters contained in the refractory gold concentrate.展开更多
The problem of arsenic(As)poisoning in the upper deltaic plains of the Ganges-Bhagirathi river system of West Bengal(WB),India,is terrifying. Elevated As(】50 ppb)in well water was observed within a depth range of 10-...The problem of arsenic(As)poisoning in the upper deltaic plains of the Ganges-Bhagirathi river system of West Bengal(WB),India,is terrifying. Elevated As(】50 ppb)in well water was observed within a depth range of 10-30 m in older grey terraces of abandoned fluvial channel deposits in the Murshidabad and Malda districts in WB.Both surface and cored(2-20 m)sediment samples from banks of the river Ganges and along a north-south transect of the main tributary Bhagirathi-Hooghly river展开更多
Agricultural liming materials are often applied to the adjustment of soil acidity and the improvement of plant growth and microbial functionality.Relatively low-grade agricultural lime was found to contain up to 125 m...Agricultural liming materials are often applied to the adjustment of soil acidity and the improvement of plant growth and microbial functionality.Relatively low-grade agricultural lime was found to contain up to 125 mg/kg arsenic(As),which is above any fertilizing materials’ toxicity threshold limit.Several techniques were employed to determine the speciation of the arsenic.Results from microprobe analyses suggest that minor minerals such as black and brown dendrites are the source of high arsenic concentrations in the samples.X-ray fluorescence spectroscopy provided further information that ferrihydrite and crystalline goethite are responsible for hosting the high concentration of arsenic with Fe/As molar ratio in around 100.A five-step sequential extraction demon-展开更多
Arsenic,a carcinogenic substance,occurs in surface and subsurface waters through natural and anthropogenic activities.It is estimated that nearly 100 million people inhabiting several countries are at a potential risk...Arsenic,a carcinogenic substance,occurs in surface and subsurface waters through natural and anthropogenic activities.It is estimated that nearly 100 million people inhabiting several countries are at a potential risk of arsenic exposure,and several thousands have already been affected by chronic arsenicosis.Therefore,there is a pressing need to develop a low cost and technically effective arsenic removal technology.While the展开更多
The kinetics of leaching arsenic from Ni-Mo ore roasting dust was investigated. The effects including leaching temperature, particle size of the smelter dust, stirring speed, the coefficient β（the molar ratio of sod...The kinetics of leaching arsenic from Ni-Mo ore roasting dust was investigated. The effects including leaching temperature, particle size of the smelter dust, stirring speed, the coefficient β（the molar ratio of sodium chlorate to arsenic in the smelter dust） and the initial H＋ concentration on leaching arsenic were studied. The results indicate that the leaching of arsenic increases sharply with the decrease of particle size. The orders of reaction with respect to H＋ concentration and particle size are determinted to be 1.136 and 1.806, respectively. The leaching of arsenic reaches 99% under experimental conditions, the apparent activation energy is determined to be 11.157 kJ/mol, which is consistent with the values of activation energy for diffusion model The kinetics equation of leaching arsenic from the roasting dust could be expressed by a semi-empirical equation as 1-2/3η （1 -η）^2/3 = k0（c[H＋]）^1.136ro^-1.806 exp[（-11157 /RT）t].展开更多
Arsenic in drinking water is a worldwide health problem that is associated with cardiovascular disease, but the cause is currently unknown. In order to examine whether arsenic affects vasomotor tone in blood vessels, ...Arsenic in drinking water is a worldwide health problem that is associated with cardiovascular disease, but the cause is currently unknown. In order to examine whether arsenic affects vasomotor tone in blood vessels, we investigated the effect of arsenic on agonist-induced vasorelaxation and vasoconstriction using the isolated rat aortic rings in in vitro organ bath system. Treatment with inorganic arsenite (AsⅢ) inhibited acetylcholine-induced relaxation of aortic rings by inhibiting production of nitric oxide in endothelium.展开更多
基金supported by the Science and Technology Innovation Program of Hunan Province,China(2020SK2073).
文摘Objective:Previous studies have demonstrated that the metals cadmium and arsenic exhibit estrogen-like effects and may influence the occurrence and development of gynecological tumors.This study aims to explore the association between urinary cadmium and arsenic levels and the prevalence of gynecologic cancers using data from the National Health and Nutrition Examination Survey(NHANES).Methods:Data from female participants in NHANES 2003—2018 were analyzed.Using R software,datasets(DEMO,BMX,etc.)were merged,and complete cases were retained by intersecting row names,yielding a total of 2999 participants.After applying strict exclusion criteria,2802 participants were included:83 with gynecologic cancer(cancer group)and 2719 without(control group).Demographic,reproductive health,and urinary cadmium and arsenic data were collected.Binary Logistic regression models were employed to assess associations between urinary cadmium and arsenic levels and gynecologic cancer risk.Results:High urinary cadmium and arsenic levels were risk factors for gynecologic cancers,with odds ratios(ORs)of 1.623(95%CI 1.217 to 2.166)and 1.003(95%CI 1.001 to 1.005),respectively.After propensity score matching(PSM),the trend remained;cadmium was still a statistically significant risk factor with an OR of 2.182(95%CI 1.343 to 3.545),while arsenic’s association,though not statistically significant,still trended toward risk(OR=1.004,95%CI 0.999 to 1.009).Subgroup analyses showed that both cadmium and arsenic were risk factors for ovarian cancer(OR=1.745,95%CI 1.178 to 2.586 and OR=1.005,95%CI 1.002 to 1.008,respectively);these associations persisted after PSM.Additionally,cadmium increased the risk of endometrial cancer(OR=1.617,95%CI 1.109 to 2.356).Conclusion:Exposure to cadmium and arsenic is associated with an increased risk of ovarian and endometrial cancers.These findings suggest that reducing environmental exposure to heavy metals such as cadmium and arsenic may help prevent certain gynecologic cancers.
基金Project(52174385)supported by the National Natural Science Foundation of ChinaProjects(2023YFC3904003,2023YFC3904004,2023YFC390400501)supported by the National Key R&D Program of China。
文摘Copper is a strategic metal that plays an important role in many industries.In copper metallurgy,electrolytic refining is essential to obtain high-purity copper.However,during the electrolytic refining process,impurities such as arsenic are introduced into the electrolyte,which significantly affect the subsequent production and quality of copper products.This paper first discusses the sources,forms,and transformation pathways of arsenic in copper electrolyte during the electrolytic process,then reviews various arsenic removal technologies in detail,including electrowinning,adsorption,solvent extraction,ion exchange,membrane filtration,and precipitation.Particular emphasis is placed on electrowinning,which is the most widely used and mature among these arsenic removal techniques.The paper evaluates these methods based on arsenic removal efficiency,cost effectiveness,technical maturity,environmental friendliness,and operation simplicity.In addition,the paper explores future trends in copper electrolyte purification,focusing on waste reduction at source,resource utilization,intelligent digitalization,and innovations in materials and processes.This review aims to provide researchers and practitioners with a comprehensive and in-depth reference on arsenic removal methods in copper electrolytes.
基金Project(52174384)supported by the National Natural Science Foundation of ChinaProject(LZB2021003)supported by Fundamental Research Funds for the Central Universities,China。
文摘Massive amounts of low-grade tin middlings have been produced from tin tailings,in which arsenic and tin are worthy to be recycled.Owing to high sulfur content in these tin middlings,a novel self-sulfurization roasting was proposed to transform,separate and recover arsenic and tin in this research.There was no extra curing agent to be added,which decreased the formation of pollutant S-containing gas.The self-sulfurization process involved a two-stage roasting of reduction followed by sulfurization.First in reduction roasting,FeAsS decomposed to FeS and As and the As then transformed to As_(4)(g)and As_(4)S_(4)(g),via which the arsenic was separated and recovered.The arsenic content in the first residue could be decreased to 0.72 wt.%.Accompanied with it,the FeS was firstly oxidized to Fe_(1−x)S and then to SO_(2)(g)by the coexisted Fe_(2)O_(3),and finally reduced and combined with the independent Fe_(2)O_(3)to form Fe_(1−x)S.In the followed sulfurization roasting,the Fe_(1−x)S sulfurized SnO_(2)to SnS(g),due to which tin could be recovered and its content in the second residue decreased to 0.01 wt.%.This study provided an efficient method to separate and recover arsenic and tin from low-grade tin middlings.
基金Project(51234009)supported by the National Natural Science Foundation of ChinaProject(2014DFA90520)supported by International Cooperation Program of Ministry of Science of ChinaProject(2013A100003)supported by the Production,Teaching and Research Program of Guangdong Province,China
文摘A process was proposed to convert and separate selenium and arsenic in copper anode slime(CAS) by low-temperature alkali fusion process.Central composite design was employed to optimize the effective parameters,in which Na OH/CAS mass ratio,fusion temperature and fusion time were selected as variables,and the conversion ratio of selenium and arsenic as responses.Second-order polynomial models of high significance and 3D response surface plots were constructed to show the relationship between the responses and the variables.Optimum area of >90% selenium conversion ratio and >90% arsenic conversion ratio was obtained by the overlaid contours at Na OH/CAS mass ratio of 0.65-0.75,fusion temperature of 803-823 K and fusion time of 20-30 min.The models are validated by experiments in the optimum area,and the results demonstrate that these models are reliable and accurate in predicting the fusion process.
基金Project(2019YFC1803601)supported by the National Key Research and Development Program of ChinaProject(41771512)supported by the National Natural Science Foundation of ChinaProject(2018RS3004)supported by Hunan Science&Technology Innovation Program,China。
文摘Iron-modified biochar(FeOS)is known to be effective at immobilization of arsenic(As)in soils.A pot experiment was conducted to investigate the effects of FeOS on As availability and ttransportation in the soil-rice system at different growth stages of rice with different pollution levels.The results showed that Fe concentration decreased and As concentration increased in paddy soils with the FeOS addition,especially in 120 mg/kg As treatment,the As concentration decreased by 16.46%and 30.56%at the maturity stage with 0.5%and 1%FeOS additions,respectively.Compared with the control,the application of FeOS reduced the arsenic content in rice tissues and increased the biomass,with the root biomass increased by 12.68%and the shoot biomass was increased by 8.94%with the addition of 1%FeOS.This may be related to the promotion of iron plaque formation and the transformation of microbial community structure in FeOS treatments,in accordance with the result of gene abundance and Fe/As contents of iron plaque in the study.This study is expected to provide further support and theoretical basis for the application of FeOS in the remediation of As contaminated paddy soil.
基金Project(51874356)supported by the National Natural Science Foundation of China
文摘Water leaching of As2O3 from metallurgical dust containing various metals was investigated,serving the purpose of dearsenization and simultaneous metal enrichment especially for indium.Effects of leaching temperature,liquid/solid ratio(LSR)and leaching time were studied.It was found that the initial dissolution was very fast but was then so inhibited by the increasingly dissolved As2O3,which makes it difficult to saturate enough arsenic in the leaching solution or in leaching out all the soluble arsenic with excess dosage of water within acceptable time(120 min).Only about 73%of As2O3 was extracted under the optimal conditions investigated.Two-step leaching showed similar trends and was thus unnecessary for improving As2O3 extraction.These observations could reasonably be accounted for the reversibility of the dissolution reaction.Kinetically,the leaching was described satisfactorily by the semi-empirical Avrami model with the apparent activation energy of 36.08 kJ/mol.The purity of the obtained product As2O3 could reach 98.7%,while the indium could be enriched in the leaching residue without loss.
基金Project(41771512)supported by the National Natural Science Foundation of ChinaProject(2018RS3004)supported by Hunan Science&Technology Innovation Program,China
文摘Bibliometrics is an important branch in the field of information science,and it is widely used in many disciplines in modern research.A current active research subject can be analyzed and summarized from many aspects,such as the core institutions,core authors,highly cited papers,and keywords by using bibliometrics.This paper describes a bibliometric analysis regarding soil arsenic content by using the database from Web of Science to compare relevant research from work done domestically and abroad from 2005 to 2016.The results show that the relevant publications in China and overseas both dramatically increased from 2009,which indicates that research activity is expanding.The USA produced 27.3%of all relevant articles followed by China with 26.9%and India with 9.5%.Key issues mainly focused on agriculture and environmental science.Major journals studied include the following:Science of the Total Environment,Environmental and Experimental Botany,Environmental Pollution,Chemosphere,Journal of Hazardous Materials,Journal of Environmental Chemical Engineering,Journal of Geochemical Exploration,Ecotoxicology and Environmental Safety,Environmental Research,Talanta,and Applied Geochemistry.These are the most important journals in this field.In light of cooperation between countries,it is clear that China and the United States occupy the leading position.
文摘Objective To observe the apoptosis of osteosarcoma MG-63 cells induced by As2O3 and to explore its possible mechanisms. Methods The flowcytometric analysis and transmission electronmicroscope were performed to investigate the inducing apoptosis and inhibitative of As2O3 on osteosarcoma MG-63 cells. In order to study mechanism of apoptosis in MG-63 cells treated with As2 O3, microarray was performed. The down-regulated gene was confirmed by RT-PCR, Northern-blotting. Results After treated with As2O3, hypodiploid peak before G0/G1 phase was observed in MG-63 cells through FCM analysis. Loss of microvilli, condensation and fragmentation of nuclear chromatin, condensation of cytoplasmic organelles, dilatation of the endoplasmic reticulum shrinkage of cells and alterations in cell membranes and apoptosis bodies which were observed in MG-63 cells treated with As2O3 by transmission electronmicroscope. The results of microarray show that As2 O3 induced MG-63 cell apoptosis involves down-regulation of IEX-1 and the down-regulated gene is confirmed by RT-PCR and Northern-blotting.Conclusion The results show that As2 O3 selectively inhibits growth of the solid tumor MG-63 cells by triggering apoptosis and indicates MG-63 induced by As2O3 cell apoptosis may through the IEX-1 pathway.
基金Project(31660026)supported by the National Natural Science Foundation of ChinaProject(lzujbky-2016-152)supported by the National Basic Research Program of China
文摘Quorum sensing is one kind of cell-to-cell signalling system among microorganisms that works in response to their population density via autoinducers exemplified by AHL and oligopeptides. In this study, fourteen AHL derivatives were synthesised by a chemical synthesis method, and two types of AHL derivatives were measured and screened by crystal violet staining assay, which have more obvious inhibitory effects on A. ferrooxidans biofilms under arsenic environment. Their structures were verified through IR and NMR identification. The morphological changes of A. ferrooxidans under the influence of the AHL derivatives were compared. In addition, the effects of AHL derivatives(0.1 μg/mL and 1 μg/mL) on membrane formation of A. ferrooxidans under high concentration of arsenic resistance(1,600 mg/L) were explored. Solid experimental data firstly showed that a portion of logarithmic microorganisms were ruptured under the effect of high arsenic concentration. Secondly, the volume of the cell shrank and the number of extracellular polymeric substances decreased after the addition of the AHL derivatives at high concentrations. Therefore, we found here that two derivatives used at concentrations of 0.1 μg/mL and 1 μg/m L accompanied with high concentration of arsenic can both effectively restrict biofilms formation by A. ferrooxidans.
基金Project(2011AA061001)supported by the National High Technology Research and Development Program of ChinaProject(51304251)supported by the National Natural Science Foundation of China+1 种基金Project(2013M542141)supported by China Postdoctoral FoundationProject(K1201010-61)supported by Planned Program of Science and Technology of Changsha,China
文摘A field study was conducted to determine the behavior and distribution of arsenic during the pyrometallurgy process in a typical SKS(Shuikoushan) lead smelter in Hunan province, China. Environmental influences of arsenic in selected samples were evaluated. Arsenic contents in all input and output samples vary from 0.11% in raw lead to 6.66% in collected dust-2. More arsenic is volatilized in blast furnace and fuming furnace(73.02% of arsenic input) than bottom blowing furnace(10.29% of arsenic input).There are 78.97%, 13.69%, 7.31% of total arsenic distributed in intermediate materials, stockpiled materials and unorganized emissions, respectively. Matte slag-2, collected dust-1 and secondary zinc oxide are hazardous based on the arsenic concentrations of toxicity characteristic leaching procedure. According to risk assessment code(RAC) guideline, arsenic in collected dust-1 poses a very serious risk to the surrounding environment, arsenic in speiss, matte slag-2, water-quenched slag and secondary zinc oxide show low risk, while arsenic in matte slag-1, collected dust-2 and post dust has no risk to the environment.
基金Project(2010CB630903)supported by the National Basic Research Program of ChinaProject(31200382)supported by the Chinese Science Foundation for Distinguished Group,China
文摘A refractory gold concentrate with 19% arsenic was treated by a mixed moderately thermophiles in an airlift bioreactor through an adaptation protocol. The moderately thermophiles could respond well to 20%(w/v) pulp density with less than 10% loss of productivity, and resist arsenic up to 15 g/L. There were a lot of jarosite, arsenolite and sulfur, but not scorodite and ferric arsenate in the bioleached residue. Jarosite passivation and lower sulfur-oxidizing activity of the cells due to the toxicity of the high concentrations of soluble arsenic and iron ions at low p H value should mainly response for the incomplete extraction at high pulp density. The initial bacterial community did not change in nature except for new found P aeruginosa ANSC, but sulfur-oxidizing microorganisms have been dominant microorganisms after a long time of adaptation. Pseudomonas aeruginosa originating from the gold concentrate should be closely relative to the metabolism of the organic matters contained in the refractory gold concentrate.
文摘The problem of arsenic(As)poisoning in the upper deltaic plains of the Ganges-Bhagirathi river system of West Bengal(WB),India,is terrifying. Elevated As(】50 ppb)in well water was observed within a depth range of 10-30 m in older grey terraces of abandoned fluvial channel deposits in the Murshidabad and Malda districts in WB.Both surface and cored(2-20 m)sediment samples from banks of the river Ganges and along a north-south transect of the main tributary Bhagirathi-Hooghly river
文摘Agricultural liming materials are often applied to the adjustment of soil acidity and the improvement of plant growth and microbial functionality.Relatively low-grade agricultural lime was found to contain up to 125 mg/kg arsenic(As),which is above any fertilizing materials’ toxicity threshold limit.Several techniques were employed to determine the speciation of the arsenic.Results from microprobe analyses suggest that minor minerals such as black and brown dendrites are the source of high arsenic concentrations in the samples.X-ray fluorescence spectroscopy provided further information that ferrihydrite and crystalline goethite are responsible for hosting the high concentration of arsenic with Fe/As molar ratio in around 100.A five-step sequential extraction demon-
文摘Arsenic,a carcinogenic substance,occurs in surface and subsurface waters through natural and anthropogenic activities.It is estimated that nearly 100 million people inhabiting several countries are at a potential risk of arsenic exposure,and several thousands have already been affected by chronic arsenicosis.Therefore,there is a pressing need to develop a low cost and technically effective arsenic removal technology.While the
基金Project(DY125-11-T-02)supported by the International Waters Resources Investigation and Development of"12.5",ChinaProject(A2012-102)supported by the Foundation of Changsha Institute of Mining and Metallurgy,China
文摘The kinetics of leaching arsenic from Ni-Mo ore roasting dust was investigated. The effects including leaching temperature, particle size of the smelter dust, stirring speed, the coefficient β（the molar ratio of sodium chlorate to arsenic in the smelter dust） and the initial H＋ concentration on leaching arsenic were studied. The results indicate that the leaching of arsenic increases sharply with the decrease of particle size. The orders of reaction with respect to H＋ concentration and particle size are determinted to be 1.136 and 1.806, respectively. The leaching of arsenic reaches 99% under experimental conditions, the apparent activation energy is determined to be 11.157 kJ/mol, which is consistent with the values of activation energy for diffusion model The kinetics equation of leaching arsenic from the roasting dust could be expressed by a semi-empirical equation as 1-2/3η （1 -η）^2/3 = k0（c[H＋]）^1.136ro^-1.806 exp[（-11157 /RT）t].
文摘Arsenic in drinking water is a worldwide health problem that is associated with cardiovascular disease, but the cause is currently unknown. In order to examine whether arsenic affects vasomotor tone in blood vessels, we investigated the effect of arsenic on agonist-induced vasorelaxation and vasoconstriction using the isolated rat aortic rings in in vitro organ bath system. Treatment with inorganic arsenite (AsⅢ) inhibited acetylcholine-induced relaxation of aortic rings by inhibiting production of nitric oxide in endothelium.
