地下水中常见离子对催化还原去除硝酸盐的影响

采用间歇式完全混合反应器对催化还原硝酸盐进行试验性研究,考察了水中共存离子对硝酸盐还原特性的影响。结果表明,Cl-、SO42-对硝酸盐的去除效率没有产生影响,而HCO-3的存在,则会导致硝酸盐的去除效率降低,最终形成的副产物NH 4浓度增加;水中的阳离子对硝酸盐的去除效率则以下列次序增加:K

Effect of Normal Ions on Catalytic Nitrate Reduction in Groundwater

Groundwater polluted by nitrate is becoming a critical issue in China and worldwide.Catalytic denetrification of nitrate over Pd-Cu bimetallic catalyst shows a potential technique for the removal of nitrate from groundwater.In this study,the reduction experiments of nitrate over catalysts was carried out in a batch reactor,and the effect of the normal ions in groundwater on both the nitrate consumption rate and reaction selectivity to N2 was quantitatively discussed.It was found that chlorides and sulfates in the reaction medium had no effect on either the extent of nitrate reduction or reaction selectivity,while the temporary hardness of drinking water decreased the removal efficiency of nitrate and increased the formation of ammonia.On the other hand,the initial nitrate activity was found to increase slightly in the following order of reactants:KNO3 < NaNO3 < Ca(NO3)2 < Mg(NO3)2,while the final ammonia yields were slightly decreased as the same order as above.However,the reaction selectivity slightly improved in the presence of Fe3 and Mn2 .