Removal of lead from wastewater by adsorption using acid-activated clay.

The suitability of acid-activated clay for adsorbing lead from wastewater streams was tested by conducting experimental studies in the laboratory. The effect of initial concentration of the adsorbate on lead removal was analysed using solutions with lead concentrations ranging from 20-120 mg/l. Also, the effect of pH on removal of lead was studied in the pH range of 2-10 and the effect of adsorbent dosage was studied by varying the adsorbent dosage from 10-20 g/l. The tests were conducted at three different temperatures, 25 degrees C, 30 degrees C and 35 degrees C. The efficiency of lead removal was observed to be about 92.4% at an initial concentration of 100 mg/l of lead, at pH 6 and at a temperature of 30 degrees C. The adsorption isotherms were plotted. The Langmuir isotherm fitted the experimental data reasonably well. The adsorption process followed the pseudo second-order model.