Donggang Sewage Treatment Plant Treatment Plan Research And Analysis Of Operational Effects

Direct discharge of municipal wastewater in Donggang seriously polluted city rivers and ocean environment,port offshore monitoring indicators of individual monitoring has been more than second class of water quality standards,and indicators of groundwater more than drinking water standard so that it can not be for drinkwater.Therefore,the government intends to construct Donggang sewage treatment plant to solve the urban sewage of serious pollution,land and sea to ensure sustained,stable and rapid development of national economy,to protect the ecological environment and tourism resources.Pollutant emission standards formulated means it must build more reasonable and efficient urban sewage treatment facilities.In order to meet the requirements of treatment effect and emissions,scheme comparison and design calculation of sewage treatment plants is particularly important.This topic take Donggang sewage treatment plant project as the research object.The treatment process and design parameters of Donggang wastewater treatment plant were studied.The research contents include the analysis of the water quality and quantity of the sewage treatment plant,the selection and analysis of the process scheme,the selection and design calculation of the structure,and the analysis and discussion of the effect of the operation.Using three kinds of methods per capita comprehensive water consumption index,unit construction land index method and the different nature of land for water consumption index method to forecast the water demand in the region,according to the prediction of water demand calculation to determine the 87%Donggang city sewage treatment plant design capacity of 30000m3/d.In accordance with the construction of water quality monitoring results,reference to domestic similar scale plant feed water quality,determine the feed water quality for the sewage treatment plant design,the engineering design of water blended with an integrated sewage,industrial wastewater and garbage leachate treatment after 'wastewater is given priority to:CODcr = 450 mg/L,BOD5 = 200 mg/L,pH =6?9,SS = 200 mg/L,NH3-N = 32 mg/L,TN ?40 mg/L,TP = 3.5 mg/L.A part of the effluent is used as industrial circulating cooling water discharged into the river as a part of the landscape water,water quality should reach the city sewage treatment plant pollutant discharge standard(GB18918-2002)level of A discharge standard:COD?50 mg/L,BOD?10 mg/L,SS?10 mg/L,NH3-N<5 mg/L,TN<15 mg/L,TP?0.5 mg/L.In combination with the practical situation of Donggang certain urban sewage treatment plant and the design requirements,the selection of pretreatment + primary treatment,secondary processing,deep processing and process flow of sludge treatment.Among them,according to the characteristic of the quality of water,increase the filter cloth filter after secondary treatment in order to improve the removal efficiency of total phosphorus;Secondary treatment to choose two to compare technical economy of more mature technology at home and abroad,finally adopted CASS process based on activated sludge process.CASS technology has 4 pools?Operation cycle is 6 hours:aeration stage 2.5 hours,precipitation stage 1.5 hours,decanter stage 1 hour,idle stage 1 hour.The results of 3 month trial operation showed that the effluent indexes of Donggang wastewatertreatmentplant:COD=32.04mg/L,TN=12.56mg/L,TP=0.43mg/L,NH3-N=1.54mg/L SS=7mg/L.This have meet the requirements of water quality.The cyclic activated sludge system(CASS process)+ cloth filter + chlorine dioxide disinfection process for sewage treatment plant in Donggang City,to ensure the effluent reached the "urban sewage treatment plant pollutant discharge standard"(GB18918-2002)-A standard.The use of sewage treatment plant in Donggang is of great significance to protect the surrounding water environment.