Quantitative Separation of As(III) and As(V) from a Synthetic Water Solution Using Ion Exchange Columns in the Presence of Fe and Mn Ions     

Prasenjit Mondal  Chandrajit Balomajumder  Bikash Mohanty 《洁净——土壤、空气、水》2007,35(3):255-260

The quantitative separation of As(III) from a water sample containing As(III) and As(V) in the presence of Fe and Mn in an ion exchange resin (AG1 X8) column for the speciation of arsenic is described. Individual and combined effects of Fe and Mn on the separation of As(III) from the solution have been studied separately. In absence of Fe and Mn, the ratio between the As(T) concentration in the eluent and the As(III) concentration in the original sample has been found to be 0.9717 under optimum process conditions. The presence of Fe(II) in the water sample increased the As(T) concentration in the eluent whereas Mn(II) decreased it. Combined effects of Fe and Mn on the percentage increment in the eluent arsenic concentration have been expressed by additive and interactive models. The interactive model has been developed by a statistical software with a 95 % confidence level. In most of the cases the error on the determination of the As(III) concentration had a minimum when using the interactive model.  相似文献   

Hydrogeochemical contrast between two study areas of Bengal delta,India: A comparative insight to understand arsenic mobilization process in shallow aquifers     

《Chemie der Erde / Geochemistry》2021,81(1):125680

A comparative hydrogeochemical study evaluated arsenic release mechanism and differences in contamination levels in the shallow groundwater of two areas within the deltaic environment of West Bengal (i.e. Karimpur and Tehatta blocks of Nadia district) in India. Groundwaters from both the areas are Ca-Na(K)-Cl-HCO₃ type with highly reducing character (−110.16 ± 16.85 to −60.77 ± 16.93 mV). Low correlations among As, Fe, and Mn and the higher association between As and DOC are indicative of microbial decomposition of organic matter enhancing the weathering of shallow aquifer materials. Arsenic contamination in groundwater is higher in Karimpur (95 ± 81.17 μg/L) than that in Tehatta (43.05 ± 41.06 μg/L). The release mechanism of arsenic into groundwater is very complex. Low Fe (0.27–4.78 mg/L and 0.81–4.13 mg/L), Mn (0.08–0.2 mg/L and 0.03–0.22 mg/L), and SO₄²⁻ (3.82 ± 0.31 and 2.78 ± 0.40 mg/L) suggest that the mechanism of arsenic release is not a single mechanistic pathway. Clustering of redox-active parameters in the principal component planes indicate that the reductive dissolution, and/or weathering/co-precipitation of Fe/Mn-bearing minerals in the shallow aquifer sediments control the dominant mechanistic pathway of arsenic release.  相似文献   

Solid-solution partitioning of arsenic （As） in the paddy soil profiles in Chengdu Plain, Southwest China     

Xiaoyan Yang  Qingye Hou  Zhongfang Yang  Xin Zhang  Yijun Hou 《地学前缘(英文版)》2012,3(6):901-909

To predict the long-term behavior of arsenic(As) in soil profiles,the solid-solution partitioning of As was studied in four paddy soil profiles obtained from agricultural areas in Chengdu Plain,Southwest China.Paddy soil profile samples were collected and soil solution samples were extracted.Total As contents in soil solution and soil solid were analyzed,along with the soil solid phase properties.The As in soil solution was significantly higher in the upper layer(0—20 cm) and had a definite tendency to decrease towards 40 cm regardless of the sampling locations.When the concentration of arsenic in soil solution decreased,its content in solid phase increased.Field-based partition coefficient(K_d) for As was determined by calculating the ratio of the amount of As in the soil solid phase to the As concentration in the soil solution.K_d values varied widely in vertical samples and correlated well with soil pH,total organic carbon(TOC) and total As. The results of this study would be useful for evaluating the accumulation trends of arsenic in soil profiles and in improving the management of the agricultural soils.  相似文献   

Selenium and heavy metals content in some Mediterranean soils   总被引：1，自引：0，他引：1  

L. Roca-Perez  C. Gil  M.L. Cervera  A. Gonzálvez  J. Ramos-Miras  V. Pons  J. Bech  R. Boluda 《Journal of Geochemical Exploration》2010

The study of metal contents in industrial, agricultural or/and polluted soils compared with natural or unpolluted soils is currently necessary to obtain reference values and to assess soil contamination. Nonetheless, very few works published appear in international journals on elements like Se, Li and Sr in Spanish soils. This study determines the total levels of Se, Li, Sr, As, Cd, Co, Cr, Cu, Ni, Pb, V, Zn, Fe, Mn and Ba in 14 natural (unpolluted) soils (Gypsisols, Leptosols, Arenosols and Acrisols), 14 agricultural soils (Anthrosols, Fluvisols and Luvisols), and 4 industrial–urban affected-surface soil horizons (Anthrosols and Fluvisols) of Eastern Spain. The geochemical baseline concentrations (GBC) and reference values (RV) have been established, and the relationships among elements and also between soil properties and elemental concentrations have been analysed. The RV obtained in this study were (mg kg⁻¹): Se 2.68, Li 115, Sr 298, Cd 0.97, Co 35, Cr 217, Cu 46, Ni 50, Pb 137, V 120, Zn 246, Fe 124,472, Mn 2691, and Ba 743. The RV for Se and Li were used as a preliminary approach to assess soil contamination in Spanish soils. The results confirm human impact on Sr, As, Cd, Cr, Cu, Ni, Pb and Zn soil concentrations, but evidence no deviation from natural Se, Li, Co, V, Fe, Mn and Ba concentrations. The results obtained from the statistical analysis reveal significant correlations between some elements and clay and soil organic matter (SOM) contents, indicating that metal concentrations are controlled by soil composition. One particularly interesting finding is the high correlation coefficients obtained between SOM and Se, Cd, Cr, V, Fe, and Mn, and between clay and Cd, Zn, V, Fe and Mn. Once again, these facts confirm the role of SOM and clay minerals in soil functions and that soil is an ecosystem element responsible for maintaining environmental quality.  相似文献   

我国马尾藻中砷的化学形态及其季节变化   总被引：6，自引：1，他引：5  

孙飚  范晓  韩丽君  娄清香 《海洋与湖沼》1998,29(3):287-292

于１９９６年３－８月在广东、广西及青岛沿海采集了部分代表性马尾藻,采用银盐分光光度法对新鲜样品中砷的化学形态,季节变化进行了研究。结果表明,广东,广西沿海马尾藻的总砷和无机砷含量较高,其中羊栖菜的无机砷含量占其总砷的５６．７３％,说明马尾藻富集无机砷的能力较强。青岛沿海鼠尾藻和海黍子的总砷含量在生长初期最低,成熟增至最高,无机砷占总砷的比例也表现出类似的季节变化,说明藻体砷含量与其生长周期有密切联  相似文献   

Abschätzung und Beeinflussbarkeit der Arsenmobilität in kontaminierten Böden     

Franka Dankwarth  Joachim Gerth 《洁净——土壤、空气、水》2002,30(1):41-48

Assessment and Modification of Arsenic Mobility in Contaminated Soil Arsenic concentration in the seepage of contaminated soils of an old tannery site is assessed using batch and column experiments. The effect of reducing conditions, pH, and ionic strength is also investigated. The iron oxide rich subsoil (C‐horizon) is the main source of groundwater pollution with arsenic. In this horizon, mobilization can increase as a result of reducing conditions upon periodical water saturation. Therefore, the potentially mobile arsenic is determined by a reductive dissolution of the poorly crystalline iron oxide fraction using 0.1 M ascorbic acid. Arsenic concentration can be reduced from 100 μg/L to below 20 μg/L by an increase of ionic strength (e.g. by a 0.01 M CaCl₂ solution). Arsenic contaminated soils should be limed regularly in order to maintain the highest possible calcium concentration in the soil solution.  相似文献   

Zielvorgaben für Pflanzenschutzmittelwirkstoffe und andere Schadstoffe in Oberflächengewässern     

Jutta Jahnel  Christian Zwiener  Thomas J. Gremm  Gudrun Abbt‐Braun  Fritz H. Frimmel  Carola Kussatz  Dieter Schudoma  Werner Rocker 《洁净——土壤、空气、水》2001,29(4):246-253

Quality Targets for Pesticides and Other Pollutants in Surface Waters Surface waters are not only adversely affected by industrial and municipal wastewaters but also by diffuse sources. For the control of the ecological water quality, so‐called quality targets are set. The quality targets are threshold concentrations for hazardous substances related to the protected goods like water ecosystems, drinking water supply, sediments, or fishing. In this paper, quality targets for the protection of aquatic life in surface waters were derived on the basis of a concept developed by the International Commission for the Protection of the Rhine (Internationale Kommission zum Schutze des Rheins – IKSR). The quality targets for the selected hazardous substances, which mainly belong to the chemical class of pesticides, were calculated using ecotoxicological results for species of bacteria, algae, fish, and small crustaceans, as the four trophic standards of the water ecosystem. In cooperation with the Federal Environmental Agency (Umweltbundesamt – UBA) the effect data were taken from ecotoxicological data bases. According to the concept of the IKSR, the lowest test result for the most sensitive species was multiplied by an assessment factor. This proceeding concerns the difficulty in describing the complex interactions in water ecosystems with toxicity data of single laboratory experiments for a few organisms. For seven pesticides quality targets below 0.1 μg/L were proposed. These results show that the ecotoxicologically based quality targets might be even lower than the limit values for pesticides in drinking water of 0.1 μg/L. But for most of the substances the determined values are significantly higher. The great concentration range of quality targets demonstrates distinctly that one standard concentration for all pesticides could not be given with regard to the different effects on aquatic organisms.  相似文献   

Spatial analysis of groundwater quality for drinking purpose in Sirjan Plain,Iran by fuzzy logic in GIS          下载免费PDF全文

Negar Fathi  Mohammad Bagher Rahnama  Mohammad Zounemat Kermani 《地下水科学与工程》2020,8(1):67-78

At present,due to shortage of water resources,especially in arid and semiarid areas of the world such as Iran,exploitation of groundwater resources with suitable quality for drinking is of high importance.In this regard,contamination of groundwater resources to heavy metals,especially arsenic,is one of the most important hazards that threaten human health.The present study aims to develop an approach for presenting the groundwater quality of Sirjan city in Kerman Province,based on modern tools of spatial zoning in the GIS environment and a fuzzy approach of evaluating drinking water in accordance with the standards of world health organization(WHO).For this purpose,qualitative data related to 22 exploitation wells recorded during 2002 to 2017 were used.In addition,fuzzy aggregate maps were prepared in two scenarios by neglecting and considering arsenic presence in groundwater resources.The results showed a decrease in groundwater quality over time.More specifically,neglecting the presence of arsenic,in 2002,all drinking wells in the area were located in an excellent zone,while in 2017 a number of operation wells were located in the good and medium zone.Also,the final map,considering the presence of arsenic as a limiting factor of drinking water,indicated that parts of the southern regions of the plain would be the best place to dig wells for drinking water.Therefore,the use of new methods can contribute significantly to the usage of groundwater aquifers and provide a good view of the aquifer water quality.  相似文献