Experimental study on adsorption of Cu2+ and Cd2+ by residual sludge

Abstract:

For effective utilization of residual sludge,biosorption experiments of Cu2+ and Cd2+ were carried out using waste activated sludge from municipal sewage treatment plant as adsorption material,and the effects of pH value,temperature,reaction time,sludge quantity and initial solution concentration on the adsorption efficiency were studied through static state experiment.Results indicate that temperature has no significant effect on the adsorption,while pH value is the most important factor in the adsorption process and the increase of sludge quantity will enhance the adsorption capacity greatly.Besides,the adsorption process of Cu2+ and Cd2+ is in accordance with Langmuir isotherm and Freundlich model,and the maximum adsorption amounts at room temperature(20±2℃) are 32.4 mg/g and 30.2 mg/g respectively.It is indicated that the residual sludge can be used as an effective biosorbent for the removal of heavy metals.