Adsorptive Removal of Chemical Oxygen Demand and Color on Sewage Sludge Based Activated Carbon from Biologically Pretreated Coking Wastewater

The preparatin of activated carbon AC-Z from sewage sludge by zinc chloride activation and its adsorption performances toward the organic compounds responsible for the chemical oxygen demand (COD) and color form biologically pretreated coking wastewater were studied. The adsorption process was performed under different pH, adsorbent dosage, contact time and temperature conditions. The Langmuir isotherm model was employed to describe the equilibrium isotherm and the data fit it very well. Langere pseudo-first order and pseudo-second order models were used to find out the kinetic parameters and the latter provied a perfect correlation for kinetic adsorption data. According to the experimental results, sewage sludge based activated carbon AC-Z may be an effective and low-cost adsorbent for the advanced treatment of coking wastewater.