Evaluation of copper adsorption from industrial wastewater using sewage sludge ash

Abstract

A BSTRACT The objective of this research work is to highlight the importance of using waste material such as sewage sludge, as a starting material for adsorption of heavy metals. Sludge incineration can help to stabilize and reduce the volume of sewage sludge; and the resultant ash (SSA) has been considered as an adsorbent for the removal of heavy metals from industrial waste water. In batch process, the effect of environmental condition such as adsorbate concentration (12.5, 25, 50 and 100 mg/L) was studied to evaluate the removal efficiency of SSA. Also, the effects of weight ratio of SSA (0.1, 0.5, 1 and 3 mg/100 mL), agitation speed (60, 150, 200 and 250 rpm), mesh size of adsorbent (60, 65 and 90 µm), temperature (40, 50 and 60 °C) and contact time (10, 20, 30, 60, 110 and 180 min), on the removal of copper ions were investigated. The optimized experimental conditions were used for the removal of copper ions from wastewater obtained from El-Sewedy cables industry. Experimental investigations indicated that at low solute concentration of 25 mg/L and high agitation speed of 250 rpm, the removal efficiency of copper ions by SSA reached 98% with the SSA dosage equal or higher than 3 g/100 mL. Adsorption isotherm studies indicated that Langmuir model described the experimental data with R 2 values greater than 0.994. The study highlighted the ability of SSA for the removal of copper ions from industrial wastewater