Although RH300 has the smallest Qmax value, its exchangeable Pb amount is the largest (2.61 versus 0.223e0.377 mg/g), suggesting RH300 may be suitable for water treatment due to the easy separation of immobilized Pb and better recycling usage. The Pb immobilized on RH500 and RH700 was mainly acidic soluble and generally stable. Hydrocerussite is one important form within the acidic soluble fraction.