Heavy metals removal using the activated sludge

摘要

A novel complex technological process of the activated sludge was developed in order to removal copper from the wastewater containing Cu 2+ ions. Results of the single-factor experiments show that the optimum adsorption condition was pH 5.0, room temperature, adsorbent concentration 10.0 g .L -1 and equilibrium time 10 min. The adsorption equilibrium data of Cu (II) ions in optimum conditions fit well to both the Langmuir and Freundlich models with high correlation coefficient of nearly 1.00 and 0.94. And the second-order kinetic model is very suitable for the experimental kinetic data with a high correlation coefficient of 1.00 at optimum conditions. The maximum adsorption capacity of the sludge is determined as 24.3 mg g -1 (wet-weight basis), and the rate constant 63.4 g mg -1 min -1 . The concentration of Cu 2+ was around 0.04 mg .L -1 after adding new sludge, far below the request of Integrated Wastewater Discharge Standard.