Electric Field Method In Water Arsenic Removal Mechanisms And The Different Materials Studied Arsenic Removal Efficiency,

At about AD 317, the arsenic was found by Chinese people. Arsenic widely exists in nature, more than 300 kinds of minerals are known to contain arsenic. Arsenic mainly filters into water by the weathering of arsenic minerals, or by the production of human activities. It was reported that there are 110,000 tons of arsenic enter into the cycle water each year.Element arsenic is Non-toxic, but the arsenides can harm people and cause carcinogenic,teratogenic and mutagenic. Long-term consumption water with high concentration of arsenic will damage skin, liver, kidney, nervous system and reproductive system. The toxicity of arsenic compounds is relevant to its shape, and the toxicity of inorganic arsenic is greater than organic arsenic. Arsenic pollution becomes imperatively a global environmental problem at present. The control and decrease of arsenic pollution of Yangzonghai is a serious challenge.Currently, the main target is the control of arsenic pollution from industrial wastewater, and the main control methods include such techniques as precipitation, ion exchange, oxidation, adsorption, membrane separation, and biological methods, etc. Using the electric field method on the removal of arsenic in water for agricultural irrigation,aquaculture,drinking water, can be a new perspective and method to study the arsenic pollution. The arsenic in the water mainly exists as trivalent arsenic As (Ⅲ) and pentavalent arsenic As (Ⅴ). As (Ⅲ) can be transformed from the oxidation of As (Ⅴ), As (Ⅴ) in weak acid, neutral and alkaline water are electric, more than 80%, and is the primary form of arsenic.The background of this thesis is arsenic contamination in Yangzonghai, Yunnan province, for large-scale arsenic contamination by weak alkaline (pH= 8.5-9.0) of water bodies (such as lakes, reservoirs, etc.) in addition to the mechanism and experimental exploration of arsenic. The results show that removing the arsenic in water by the electric field method include three effects and the two processes: Plate metal atom ionization effect, arsenate accumulation in the anode, water electrolysis, oxidation of arsenate. Reaction of metal ions and arsenate induces the formation of insoluble arsenate, metal hydroxide and arsenate, sub-arsenite complexation reaction ( As ? O?) form of coprecipitation adsorption. These productions of reaction favor the achievement of low-carbon, efficient, pollution-free removal of arsenic in water. Electrodes with different metal materials (copper, aluminum, iron) have been used in the arsenic removal experiment. Then, we analyze and summarize the law and efficiency of removal of arsenic. On this basis, the intermittent electric field method, which can be fully realized the view of low-carbon, high efficiency, is proposed to be used in the practical application. In this thesis, the arsenic removal device has been designed, and the intermittent electric field method has been conducted, and the results of removing arsenic are better than our prevenient expected. There three orders of magnitude of arsenic concentration can be decreased by selecting the appropriate role of parameters. The remove the arsenic in water by the electric field method are well summarization in the thesis, and the features and innovations of this method are also proposed.