Removal of Cu2+ in aqueous solutions using sludge incineration slag as an adsorbent

Sewage sludge incineration slag, the waste generated in sewage sludge incineration, was obtained from a sewage treatment plant in Guangzhou and used as a low-cost sorbent for removing Cu(II) from wastewaters. The adsorption effectiveness and their factors of Cu2+ in aqueous solutions were simulated detailed using the adsorbents of the sludge incineration slag. The simulation contents and the factors included the adsorption time, the pH of solution and the dosage of adsorbents and so on. The results showed that at 30 degrees C, the adsorption equilibrium of Cu2+ can be achieved in 6h and the best pH value of the solution was about 4.5-5.5. The removal rates of Cu2+ were increased with the adsorbent concentration increasing and the optimal concentration of adsorbent was 20-30g/L with the initial concentration of Cu2+ less than 25mg/L. At the best adsorption conditions, the removal rate of Cu2+ reached more than 80% and the adsorption capacity was 0.83-1.25mg/g.