Experimental Study On The Treatment Of Municipal Wastewater Reuse For Thermal Power Plant Circulating Cooling Water System By Combined Process Of BAF And Efficient Coagulation-sedimentation

With today's rapid economic and social development, the production of human life will face a huge water crisis, so we have to treat municipal sewage as a stable freshwater resource. The shortage and pollution of water resources is very serious in China, and thermal power plant water consumption is the largest in urban industrial water. In order to provide a large number of water for the thermal power plant circulating cooling water systems, using the secondary effluent reuse for thermal power plant circulating cooling water systems is an economic and effective solution.The experiments were conducted in the beaker tests and modeling tests in this research work. Xingtai's secondary effluent was treated by the combination of BAF and efficient coagulation-sedimentation. The impact of factors, the best operating conditions and the effect of removing pollutants were analyzed.In the beaker tests, PAC is the best optimized for coagulant. When the optimum dosage was 40mg/L, pH:6⁷, turbidity and COD_Cr could be removed best.DO should be above 2mg/L in the pilot study, when the biofilm of BAF was mature, and the PAC dosage was 30mg/L, the removal efficiency of COD_Cr remained to be 63.4⁶9.2%, the concentration of COD_Cr:14.7¹6.7mg/L;the removal efficiency of turbidity remained to be 91.8⁹5.4%, the turbidity 14.7¹6.7 mg/L; the removal efficiency of NH₃-N remained to be 90.5⁹5.9%, the concentration of NH₃-N:0.4¹.2mg/L.However in the BAF process, the turbidity was still 7.8²2.1NTU, after efficient coagulation-sedimentation process, the turbidity could be removed less than 3 NTU. According to the experimental study, using the combination of BAF and efficient coagulation-sedimentation to deal with secondary effluent for the thermal power plant circulating cooling water system is technically feasible.According to the practical application, the actual proof is that the removal efficiency of COD_Cr remained to be 63.1⁷0.4%, the concentration of COD_Cr:10.7¹5.4mg/L; the removal efficiency of turbidity remained to be 90.8⁹6.2%, the turbidity less than 1 NTU; the removal efficiency of NH3-N remained to be 91.0⁹5.3%, the concentration of NH₃-N:0.2⁰.4mg/L.Therefore, the combined process for dealing with secondary effluent reuse for thermal power plant circulating cooling water system is economically viable and technically feasible. This practical application has good water quality, low running costs, significant economic, social and environmental benefits.