活性污泥对重金属离子吸附特性的研究

Research on characteristics of activated sludge adsorbing heavy metal ions

利用活性污泥作为吸附剂,吸附废水溶液中重金属离子。研究了pH值、重金属离子初始浓度对活性污泥吸附效果的影响,以及吸附重金属离子前后废水pH值的变化情况,同时探讨了pH值、 Cu^(2+)和Cd^(2+)初始浓度对活性污泥中可溶性有机物产生量的影响。结果表明,活性污泥对重金属离子具有良好的吸附效果,活性污泥对Pb^(2+)、 Cd^(2+)、 Cu^(2+)、 Zn^(2+)、 Ni^(2+)的最佳吸附pH值在7～9之间。随着初始浓度的增大,活性污泥对Zn^(2+)、 Ni^(2+)的吸附率降低,对Cd^(2+)的吸附率升高,对Cu^(2+)的吸附率先升高后降低,对Pb^(2+)的吸附率无显著影响。活性污泥吸附重金属离子后溶液的pH值均向中性区域变化。溶解性有机物的产生量随着pH值的增大呈先降低后缓慢升高的趋势。在相同的pH值下溶解性有机物的产生量随着重金属离子浓度的增大而增大。

Activated sludge was used as adsorbent to adsorb heavy metal ions in wastewater.The effects of different pH values,initial concentrations of heavy metal ions on the adsorption performance of activated sludge as well as the pH variation of the wastewater before and after heavy metal ions adsorption were studied,meanwhile,the influence of pH value,initial concentrations of Cu^2+and Cd^2+on the production of soluble organic matters in activated sludge were discussed.The results showed that,activated sludge has good adsorption performance on heavy metal ions,the optimal pH value for activated sludge adsorbing Pb^2+,Cd^2+,Cu^2+,Zn2+,Ni^2+was7-9.With the increasing initial concentration,the adsorption rates of Zn2+and Ni^2+decreased;the adsorption rate of Cd^2+increased,and the adsorption rate of Cu^2+decreased after the first increase.However,initial concentration had no siginificant effect on the adsorpition rate of Pb^2+.The pH value of the solution after the activated sludge adsorbing heavy metal ions changed to the neutral region.The amount of soluble organic matters first decreased and then increased slowly with the increasing pH value.At the same pH condition,the amount of soluble organic matters increased as the heavy metal ions concentration increase.