On the basis of the properties of the flue gas desulfurization(FGD)wastewater

the principle and process flow of wastewater treatment with the environment-friendly reagent TMT were investigated.The Cd/Pb/Ni/Cu/Zn-TMT were synthetized and characterized by elemental analysis and IR.The sludge made of the metal-TMT precipitates was prepared by the FGD wastewater from a coal-fired power plant.The leaching toxicity and thermal stability of the metal-TMT precipitates were studied by ICP-AES

TG and XRD.The results show that

the TMT is a very advantageous chelating agent in precipitating metal ions.The metal-TMT precipitates can enter the landfill as the first kind of general industrial solid wastes because of the low leachability in H_2SO_4-HNO_3 agent and pure water.The metal-TMT precipitates have high thermal stability

they start decomposition at temperatures from 250 ℃ to 300 ℃ and ends at 730 ℃ to740 ℃.The breakdown products are the corresponding sulfides.The results are significant for the post disposal of FGD wastewater sludge.