Removal processes for arsenic in constructed wetlands
| Autor: | Katherine Lizama A., Tim D. Fletcher, Guangzhi Sun |
|---|---|
| Rok vydání: | 2011 |
| Předmět: |
inorganic chemicals
Environmental Engineering Iron Health Toxicology and Mutagenesis media_common.quotation_subject Alkalinity chemistry.chemical_element Wetland Arsenic Phosphates Environmental Chemistry media_common Pollutant geography geography.geographical_feature_category Bacteria integumentary system Aquatic ecosystem Temperature Public Health Environmental and Occupational Health Environmental engineering food and beverages General Medicine General Chemistry Hydrogen-Ion Concentration Plants Biodegradation Pollution Speciation Biodegradation Environmental chemistry Wetlands Environmental chemistry Environmental science Sewage treatment Sulfur Water Pollutants Chemical |
| Zdroj: | Chemosphere. 84:1032-1043 |
| ISSN: | 0045-6535 |
| DOI: | 10.1016/j.chemosphere.2011.04.022 |
| Popis: | Arsenic pollution in aquatic environments is a worldwide concern due to its toxicity and chronic effects on human health. This concern has generated increasing interest in the use of different treatment technologies to remove arsenic from contaminated water. Constructed wetlands are a cost-effective natural system successfully used for removing various pollutants, and they have shown capability for removing arsenic. This paper reviews current understanding of the removal processes for arsenic, discusses implications for treatment wetlands, and identifies critical knowledge gaps and areas worthy of future research. The reactivity of arsenic means that different arsenic species may be found in wetlands, influenced by vegetation, supporting medium and microorganisms. Despite the fact that sorption, precipitation and coprecipitation are the principal processes responsible for the removal of arsenic, bacteria can mediate these processes and can play a significant role under favourable environmental conditions. The most important factors affecting the speciation of arsenic are pH, alkalinity, temperature, dissolved oxygen, the presence of other chemical species--iron, sulphur, phosphate--,a source of carbon, and the wetland substrate. Studies of the microbial communities and the speciation of arsenic in the solid phase using advanced techniques could provide further insights on the removal of arsenic. Limited data and understanding of the interaction of the different processes involved in the removal of arsenic explain the rudimentary guidelines available for the design of wetlands systems. |
| Databáze: | OpenAIRE |
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