活性污泥对铜和无机氮单一及复合污染的吸附研究

Adsorption of Activated Sludge for Copper and Inorganic Nitrogen in Single and Compound Pollution

该研究对比分析了活性污泥在铜离子(Cu^(2+))、NH_(4)^(+)、NO_(3)^(-)单一及二元、三元复合污染情况下的吸附效果,并进一步研究了其对废水中Cu^(2+)、NH_(4)^(+)的吸附动力学和平衡等温线。结果表明本实验条件下:在单一污染情况下,活性污泥对NH_(4)^(+)和Cu^(2+)的吸附量分别达6.30 mg/g和1.38 mg/g,但对NO_(3)^(-)没有明显的吸附效果;二元复合污染情况下,当Cu^(2+)、NO_(3)^(-)分别和NH_(4)^(+)共存时均可促进活性污泥对NH_(4)^(+)的吸附,且NO_(3)^(-)表现出更显著的促进作用,而NH_(4)^(+)、NO_(3)^(-)的存在均会极显著地抑制活性污泥对Cu^(2+)的吸附(P<0.01);三元复合污染情况下,NO_(3)^(-)、Cu^(2+)的存在会促进活性污泥对NH_(4)^(+)的吸附,而NH_(4)^(+)、NO_(3)^(-)的存在会对活性污泥吸附Cu^(2+)产生极显著的抑制作用(P<0.01)。另,活性污泥吸附NH_(4)^(+)和Cu^(2+)的过程均符合Langmuir吸附等温模型,活性污泥对NH_(4)^(+)的最大吸附量为11.9204 mg/g,对Cu^(2+)的最大吸附量为23.4028 mg/g,活性污泥吸附NH_(4)^(+)和Cu^(2+)的吸附动力学过程与准一级动力学方程和准二级动力学方程拟合度均较高。研究结果可为活性污泥在重金属和营养盐复合污染废水处理中的应用提供参考。

In this study,the adsorption effect of Cu^(2+),NH_(4)^(+)and NO_(3)^(-)by activated sludge under single pollution and binary and triple compound pollution was analyzed,and the adsorption kinetics and equilibrium isotherms of Cu^(2+)and NH_(4)^(+)in wastewater were explored as well.The results showed that under the experimental conditions:in the case of single pollution,the adsorption amount of NH_(4)^(+)and Cu^(2+)by activated sludge reached 6.30 mg/g and 1.38 mg/g,respectively.No obvious adsorption ability was shown for NO_(3)^(-)under single pollution condition;In the case of dual compound pollution,the presence of Cu^(2+)and NO_(3)^(-)promoted the adsorption of NH_(4)^(+)by activated sludge,and stronger promotion was observed while coexisting with NO_(3)^(-),and the presence of NH_(4)^(+)and NO_(3)^(-)had extremely significant inhibitory effects on the adsorption of Cu^(2+)by activated sludge(P<0.01);In the case of triple compound pollution,the presence of NO_(3)^(-)and Cu^(2+)promoted the adsorption of NH_(4)^(+)by activated sludge,and the presence of NH_(4)^(+)and NO_(3)^(-)had extremely significant inhibitory effects on the adsorption of Cu^(2+)by activated sludge(P<0.01).It was concluded that the adsorption process of Cu^(2+)and NH_(4)^(+)by activated sludge conformed to the Langmuir adsorption isotherm model,the maximum adsorption amount of NH_(4)^(+)by activated sludge was 11.9204 mg/g,and the maximum adsorption amount for Cu^(2+)was 23.4028 mg/g.Both the pseudo-first-order kinetic equation and the pseudo-second-order kinetic equation provided high correlation to the data.The conclusions of this study can provide a reference for the application of activated sludge in the treatment of wastewater contaminated by heavy metals and nutrients.