| The pollutions of waste water, waste gas and waste residue generated by thermalpower plant affect people’s lives. The increasingly serious of haze of nowadays issomewhat relevant to thermal power. The wastewater sample of “Shaanxi Datang PowerGeneration Co., Ltd. Baqiao Thermoelectric Power Plant” was analyzed. Thedesulfurization wastewater was treated by plant fly ash and the lime method was chosento purify the circulating cooling water for advanced treatment. All of this water can bereused. So recycling of water resources can be realized, as well as waste control bywaste.The desulfurization wastewater was treated by residual fly ash generated by powergeneration combustion of this plant and the circulating cooling water was treated bylime coagulation combined with quartz sand, manganese sand filtration after the qualityof them had been analyzed. The treatment effect of the suspensions of desulfurizationwastewater, the desulfurization wastewater COD, fluoride, chromium, cadmium, zinc,lead and copper affected by the factors of fly ash dosage, temperature and time wasdiscussed. Lime and flocculent was added to improve effect of treatment in the light ofthe pH of waste water. The single factor experimentation showed a good treatmenteffect could be achieved after30~40min by adding15g fly ash and0.2g lime into50mldesulfurization wastewater and keeping the pH value in the range of8~9and theconcentration of conpolyaluminum chloride and polyacrylamide10mg/L and1mL/L,respectively. The orthogonal experiments further optimized the treatment effects of thewastewater desulfurization and the result showed the removal rate of COD reached74.59%, and suspended solids removal rate got to55.58%, and fluoride removal rate increased to98.34%, and the removal rates of heavy metals Cu2+, Pb2+, Zn2+, Cr3+,Cd2+were99.69%,97.88%,98.29%,99.76%and97.29%respectively after adding5.0gfly ash and0.2g lime and keeping the pH value at9and the concentration ofconpolyaluminum chloride and polyacrylamide10mg/L and1mL/L respectively for40~50min, which was a satisfactory result.The circulating cooling water of power plant was filtered by lime coagulationcombined with quartz sand, manganese sand mixture filter and the result showed it handa better treatment effect when the concentration of lime, polyaluminum chlorideand polyacrylamide was600mg/L,30mg/L,0.5mg/L, respectively. In this condition,the pH value of the effluent could be controlled in8.5~8.9, and the removal rate ofalkalinity reached86.09%, and the total hardness removal rate got to53.58%, andsuspended solids removal rate increased to82.18%, and the removal rate of CODCrwas32.35%. Meanwhile, the results demonstrated that polyacrylamide significantlyaccelerate the speed of settling velocity. The experiment of quartz sand/manganesesand filter layer iron removal showed there was no big difference for the adsorptioneffect of iron between quartz sand/manganese sand ratio of3:7filter with100%manganese sand filter, both of which could make the removal rate of iron get tomore than90%. The best effect of removal of iron could be got by adjusting the pHvalue of raw water in the range of6.5to7.5and then adding quartz sand/manganesesand mixture(with the ratio of3:7) as filter layer. |
