The effect of carbon properties and water characteristics on the adsorption of m-LR by activated carbon was evaluated using kinetic and isotherm tests. The results showed that both physical and chemical effects simultaneously affect the adsorption process. The activated carbon with a high ratio of mesopore and macropore volume showed an increased m-LR adsorption capacity. The micropores in carbon offer only a nominal internal surface for adsorption. The adsorption capabilities of different activated carbon generally followed their pH(zpc) values. Activated carbons with higher pH(zpc) values exhibit a neutral or positive charge under typical pH conditions, promoting m-LR adsorption on the carbon surface. The competitive effects of natural organic matter (NOM) on activated carbon were evaluated and showed that caused a reduction in the capacity of carbon for m-LR. Furthermore, when pre-chlorination was preceded by adsorption, then the residual chlorine would react with activated carbon caused a decrease in sorption capacity of m-LR, while that chlorine at normal treatment plant dosages is not effective for degrading m-LR. (c) 2006 Elsevier B.V. All rights reserved.