REMOVAL OF Zn FROM AQUEOUS SOLUTIONS BY LOW-RANK COAL

摘要

The ability of an immature coal (leonardite) to remove zinc from aqueous solutions was studied as a function of pH, contact time and concentration of metal solutions. Effective removal of Zn~(2+) was demonstrated at pH values of 5-6. Kinetic study showed that the adsorption of Zn~(2+) occurs in two phases: a rapid phase followed by a quasi-equilibrium state attained within the first two hours. The adsorption isotherm was measured at 25℃, using adsorptive solutions at the optimum pH value to determine the adsorption capacity.