Study On The Removal Of Arsenic From The Groundwater

Arsenic and iron,manganese in the groundwater usually concomitant existence, therefore we can consider while filtering both to filter iron and manganese with the biofilter at the same time in addition to arsenic.The arsenic is existed with As(Ⅲ) in the underground, As(Ⅲ) is hard to be adsorbed, therefore usually we need oxidize As(Ⅲ) into As(Ⅴ). This experiment mainly aims at these questions and simulated in the laboratory by arsenic contamination of groundwater, I have researched in three areas:⑴With the lately-studied new filter material to, then in addition to the manganese germ into the filter material, last make these to filter. Enter include As(Ⅲ) water to the biofilter, investigation filter capability of oxadation As(Ⅲ); Transform various condition factor, the investigation environment condition influence on filters⑵Use mature biofilter removing manganese to directly filter arsenic water, and study of arsenic removal with biological activity filter.⑶As (Ⅲ) and As(Ⅴ) were adsorbed by nascent MnO2 and commodity MnO2, then study the adsorption capacity and influencing factors.The new biofilter can remove 0.2mg/L As(Ⅲ) and have no influence on the removement to manganese. When the inlet As(Ⅲ) concentration is 0.1~0.2mg/L, 1 mg/L Fe2+ can improve the removal capacity of total arsenic and As(Ⅲ), but the filter cycle will be shorten. Raise Mn2+ concentrations can improve the removal capacity of total arsenic and As(Ⅲ) ; filtering rate should be less than 5m/h. Along with the increase of the filter bed depth, As(Ⅲ) oxadation rate increase, the As(Ⅴ) removal quantity and also raises gradually.When inlet total As concentration is 0.1mg/L in mature biofilter, the outlet total As concentration is less than 0.01 mg/L. The capacity of manganese is still less than 0.1mg/L. Sutable backwashing can revive the capacity of the removal arsenic. Contrast mature biofilter to new filter material filter , two biofilters'capacity of removal arsenic are same, both can removel 0.2mg/L As(Ⅲ) and less than 0.1mg/L total As. Which are suitable circulate under low filter rate.The adsorption ability of As(Ⅲ) and As(Ⅴ) with nascent MnO2 are stronger than MnO2. When 8mg/L nascent MnO2 and MnO2 adsorbed 0.15mg/L of As(Ⅲ) and As(Ⅴ), reaction time to reach equilibrium in less than 3h. Absorption capacity under acidic conditions are better; it under neutral and poor alkaline conditions are commonly, it under strong alkaline conditions are the strongest. With the concentration of nascent MnO2 and MnO2 increasing, the removal rate of arsenic will increase. But when MnO2 concentration is 15mg/L, the nascent MnO2 concentration is 18mg/L, the adsorption increased slowly. With the increasing of Mn2+, the As(Ⅲ) and As(Ⅴ) removal rate on manganese dioxide were increased. But at this time manganese value is greater than the national drinking water standards. without considering the concentration of manganese effluent Under the premise of whether the target can increase the concentration of raw water to enhance Mn2+ As(Ⅴ) removal.