A process of coordination polymerization precipitation was proposed as a new alternative to the conventional treatment method for removing heavy metals wastewater. A chelating reagent with two chelating groups, NN-bis-(dithiocarboxy)piperazine, was employed as the first coordination polymerization precipitant to remove copper(II) from wastewaters containing free and complex copper(II). It was observed that BDP could effectively reduce 50.00 mg/L free and complex Cu2+ in wastewater to much lower than 0.5 mg/L by bridging Cu2+ to yield highly insoluble linear chelating polymer and the polymer precipitates were easier to settle and less susceptible to leaching than copper diethyldithiocarbamate. (c) 2006 Elsevier B.V. All rights reserved.