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The combined pollution of heavy metal Pb2+ and bensulfuron-methyl (BSM), originating from chemical herbicides, in agro-ecological environments has become commonplace in south China.The adsorption of BSM on three paddy soils in the presence of Pb2+ with different levels was examined by the batch equilibration and high-performance liquid chromatograph (HPLC) techniques.Results indicated that adsorption of BSM could accurately be described by a Freundlich isotherm equation with correlation constant (R) > 0.98, irrespective of the presence of spiked Pb2+.Of the various factors influencing BSM sorption, soil pH appeared to be the most influential.The constant Kf of Freundlich isotherm equation tended to increase with increasing Pb2+ concentration in soil which indicated that the spiked of Pb2+ in paddy soils would promote the sorption of BSM.The ΔGθ of BSM in three paddy soils was less than 40 kJ/mol in all treatments, indicating adsorption of BSM is mainly physical in nature.The elution of soil dissolved organic matter (DOM) enhanced the adsorption of BSM in paddy soils.We suggested that the mechanisms involved in the promotion effects of the spiked Pb2+ on adsorption of BSM might be the modified surface characteristics of paddy soil solids due to the soil acidification and the increase of soil organic matter concentration because of DOM binding.