Study on Adsorption of Pb~(2+) in Wastewater by Acid-Modified Bentonite

Calci-bentonite was modified with using sulfuric acid as the modifier.The effects of various parameters on modified bentonite removing Pb2+ in simulate water were investigated,such as modifier amount,dosage of acid-modified bentonite,the adsorption time and the value of pH.The results showed that the bentonite modified by 20% volume concentration sulphuric acid solution had the best adsorption ability.At normal temperature,the removal rate of Pb2+ can reach more than 99.5% under the following conditions: the dosage of acid-modified bentonite is 15g/L,the adsorption time is 30min,the pH value is 6～9.The rest concentration of lead is lower than 1mg/L and it can meet the national standard of contamination discharge.