给水厂污泥颗粒制备及对铜离子的吸附行为

将给水厂污泥和粘土以质量比1：2制备了一种新型污泥颗粒，考察其对溶液中铜离子的吸附行为.结果发现，污泥颗粒对水中铜离子具有良好的吸附效果，对铜的吸附量随时间增加而增大，180min时可达最大吸附量的85%左右，吸附过程符合准二级吸附动力学方程；Langmuir等温吸附方程式可较好拟合不同温度时的吸附数据，且温度越高，平衡吸附量越大.多种重金属离子共存时，污泥颗粒仍优先吸附铜离子.pH值可显著影响污泥颗粒对铜离子的吸附，pH<5时，污泥颗粒对铜离子的吸附去除率随pH值升高而增大，pH=5时吸附去除效果最好.采用扫描电镜、红外光谱等对吸附铜离子前后的污泥颗粒进行表征，发现污泥颗粒表面粗糙、孔隙发达，含丰富表面基团，能够通过静电吸引、羟基取代和表面络合吸附铜离子.

Preparation of granular sludge from water supply plants and its adsorption behavior of copper ions

A new granular sludge synthesized with the sludge from water supply plants and clay mass at the ratio of 1:2 was developed, and its adsorption behavior towards copper (Ⅱ) was investigated. The granular sludge had favorable adsorption properties towards copper (Ⅱ), and the adsorption amounts increased with the increase of reaction time. At the reaction time of 180min, the adsorption capacity could reach 85% of the maximum adsorption capacity. The kinetic data could be described by the pseudo-second-order kinetics models. The Langmuir isotherm model performed better in fitting the adsorption data at different temperatures. The equilibrium adsorption amounts increased with the increase of the reaction temperature. The granular sludge preferred to adsorb copper (Ⅱ) in the solution mixed with other heavy metal ions. Additionally, pH (the acidity level) can significantly influence the adsorption of copper ions. The removal efficiency of copper ions increased with the increase of pH when pH lower than 5and reached the maximum value at pH 5. SEM and FTIR characterization showed that the granular sludge exhibited a rough surface and porous structure with abundant surface functional groups. Copper ions adsorption of granular sludge was achieved by electrostatic attraction, hydroxyl substituents and surface complexation.