http://netedu.xauat.edu.cn/jpkc/netedu/jpkc2009/szylyybh/content/wlzy/1/Review%20of%20Arsenic%20in%20natural%20water%20-%20Smedly.pdf

A review of the source, behaviour and distribution of arsenic in natural waters

We are just beginning to understand the metabolism of heavy metals and to use their metabolic functions in biotechnology, although heavy metals comprise the major part of the elements in the periodic table. Because they can form complex compounds, some heavy metal ions are essential trace elements, but, essential or not, most heavy metals are toxic at higher concentrations. This review describes the workings of known metal-resistance systems in microorganisms. After an account of the basic principles of homoeostasis for all heavy-metal ions, the transport of the 17 most important (heavy metal) elements is compared.

Microbial heavy-metal resistance

Remediation of heavy metal(loid)s contaminated soils - To mobilize or to immobilize?

In the deltaic plain of the Ganges-Meghna-Brahmaputra Rivers, arsenic concentrations in groundwater commonly exceed regulatory limits (.50 m gL 21 ) because FeOOH is microbially reduced and releases its sorbed load of arsenic to groundwater. Neither pyrite oxidation nor competitive exchange with fertilizer phosphate contribute to arsenic pollution. The most intense reduction and so severest pollution is driven by microbial degradation of buried deposits of peat. Concentrations of ammonium up to 23 mg L 21 come from microbial fermentation of buried peat and organic waste in latrines. Concentrations of phosphorus of up to 5 mg L 21 come from the release of sorbed phosphorus when FeOOH is reductively dissolved and from degradation of peat and organic waste from latrines. Calcium and barium in groundwater come from dissolution of detrital (and possibly pedogenic) carbonate, while magnesium is supplied by both carbonate dissolution and weathering of mica. The 87 Sr/ 86 Sr values of dissolved strontium define a two-component mixing trend between monsoonal rainfall (0.711 6 0.001) and detrital carbonate (,0.735).

https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2000WR900270

Arsenic in groundwater: Testing pollution mechanisms for sedimentary aquifers in Bangladesh

If you really want to be smarter, reading can be one of the lots ways to evoke and realize. Many people who like reading will have more knowledge and experiences. Reading can be a way to gain information from economics, politics, science, fiction, literature, religion, and many others. As one of the part of book categories, statistical methods for environmental pollution monitoring always becomes the most wanted book. Many people are absolutely searching for this book. It means that many love to read this kind of book.

Statistical Methods For Environmental Pollution Monitoring

Interaction of groundwater with As-bearing rocks has been proposed as one of three main sources of arsenic at Zimapan valley, Mexico. The complexity of the geology and hydrogeology of the valley make it difficult to identify the natural causes of arsenic poisoning. Samples from the different rock outcrops and water from wells tapping various rock formations were analyzed. The rocks from mineralized areas contained higher concentrations of arsenic with respect to the same formations in non-mineralized areas. The arsenic minerals arsenopyrite, scorodite, and tennantite were identified in some rock samples. Higher temperature and lower Eh values were found for those wells containing more arsenic. The physicochemical characteristics of these naturally polluted well waters could be produced by arsenopyrite oxidation. The geochemical model PHREEQCI was used to perform the inverse modeling of two wells located along the same fault. Arsenopyrite oxidation and scorodite dissolution appear to be the geochemical processes producing the natural pollution according to the model. The release and transport of arsenic mainly occur through fractures within the cretaceous limestones where the most productive wells are drilled. The presence of arsenic should be expected also in other formations near mineralized zones in the Zimapan Valley. Field determinations of Eh and T could be used to detect potentially polluted wells.

The role of arsenic-bearing rocks in groundwater pollution at Zimapán Valley, México

Arsenic contamination of groundwater has been detected in the Zimapan Valley, Mexico. Concentrations as much as 1.097 mg/L were observed in water pumped from one of the most productive wells. Three sources of arsenic are known. The natural source is produced by the oxidation of arsenic-bearing minerals; polluted water pumped from the deepest wells is derived from this source and has the highest concentrations. Two anthropogenic sources pollute the shallow wells. These result from the leaching of mine tailings and from the percolation of smelter fumes containing arsenic and which settled on the soil until the 1940's. The identification and evaluation of multiple sources of pollutants in aquifers are needed to establish reliable aquifer-remediation programs, especially in many arid regions, where groundwater in commonly the main or only source of drinking water.

Arsenic Contamination of Groundwater at Zimapán, Mexiko

A GIS-based DRASTIC vulnerability and net recharge reassessment in an aquifer of a semi-arid region (Metline-Ras Jebel-Raf Raf aquifer, Northern Tunisia).

Zimapán is a town of nearly 9000 inhabitants located in the central part of México. It is a semi-arid zone with an average annual precipitation of 409 mm. Most of the rain occurs in heavy storms during the summer (INEGI, 1994). In 1992, high concentrations of arsenic were determined in water from several wells, and also in the tap water. Arsenic in groundwater comes from three different sources. The highest concentrations (as much as 1.09 mg/L) result from water-rock interaction, mostly from oxidation and dissolution of arsenic-bearing minerals, in deep wells drilled in the limestone aquifer. Lower arsenic contents come from the leaching of mine tailings (as much as 0.437mg/L) and from arsenic rich fumes infiltrating through the soil (up to 0.10 mg/L) (Armienta et al., 1997). In this valley there are no superficial water bodies, therefore all of the Zimapán dwellers get their drinking water from the aquifer. Until 1996, tap water was supplied after mixing groundwater containing different arsenic concentrations, resulting in an arsenic content of around 0.3 mg/L. People living in different areas of the Zimapan valley have been exposed to various arsenic concentrations in drinking water, from trace (less than 0.014 mg/L) to 1.09 mg/L.

Ramiro Rodríguez

Papers

The role of arsenic-bearing rocks in groundwater pollution at Zimapán Valley, México

Arsenic Contamination of Groundwater at Zimapán, Mexiko

A GIS-based DRASTIC vulnerability and net recharge reassessment in an aquifer of a semi-arid region (Metline-Ras Jebel-Raf Raf aquifer, Northern Tunisia).

Arsenic content in hair of people exposed to natural arsenic polluted groundwater at Zimapán, México.

Distribution, origin and fate of chromium in soils in Guanajuato, Mexico