Research On Pollutant Removal Efficiency Of New Type Wastewater Treatment System For High Speed Rail Train Toilet

With the rapid development of China's social economy,the high-speed railway construction has developed rapidly,and the development concept of"green high-speed rail"has been implemented throughout.The huge quantity of passengers makes the standard discharge of sewage treatment of the toilet become the environmental protection difficulty of railway station in China.This kind of"five high and one low"treatment with high NH₃-N,high COD_cr,high P,high SS,high biological toxicity,low C/N is difficult to deal with.If not properly handled,it will cause impact load and environmental ecological risks on the discharged water.This article mainly studied the pollutant removal law in the sewage pilot test system of railway passenger train toilets,finds the problems in the current sewage treatment system of railway stations and depots,and developed the"MAP removal Phosphorus+integrated biological denitrification+electric ozone catalysis"pilot system"based on the anaerobic ammonia oxidation process,focused on the"AAO+CANON+OAO"new coupled denitrification process of pollutant removal efficiency and stable microbial population structure during stable operation.The migration and transformation rules of typical antibiotics were analyzed with Pearson correlation analysis and PCA principal component analysis to explore the correlation and homology between sulfonamides,tetracycline antibiotics and conventional indicators,and conducted engineering economic analysis to obtain the following main conclusions:1.For this kind of characteristic sewage,under the conditions of influent COD of about 1600mg/L,ammonia nitrogen of about 1100mg/L,and total nitrogen of about1150mg/L.The average removal rates of COD,ammonia nitrogen,and total nitrogen during the stable operation of the coupled biological denitrification process are respectively reaching 80%,99%,98.5%.the effluent COD,ammonia nitrogen,and total nitrogen concentration are less than 100mg/L,5mg/L,15mg/L.Microbial analysis results show that the nitrification,denitrification and CANON denitrification operation of each system works well and it is stable and the distribution of dominant bacteria is good.The existence of Ignavibacteria in the CANON process section indicates that there may be some iron ammonia oxidation reaction assisting the denitrification;2.The Pearson correlation analysis of sulfonamides and tetracycline antibiotics detected at the inlet end of the pilot system with conventional water quality indicators indicates the feasibility of the biodegradation pathway of antibiotics.The removal method mainly relies on biodegradation,adsorption,and advanced oxidation.The average reduction rate is more than 77%,and the residue at the outlet end is lower than that of domestic and foreign sewage treatment plants.Environmental risk assessment was carried out through the risk entropy method.SPD,SDZ,OTC,etc.at the effluent end were at medium or low risk,but SMZ still had a high environmental risk.PCA principal component analysis shows that elements in the same principal component may come from the same artificial source or mixed source;3.According to the pilot experiment results and the actual needs of the railway stations and sections,the economic benefit analysis of the scale-up project based on the"MAP method+CANON+OAO"combined process is carried out.Compared with the traditional denitrification and dephosphorization process,it is roughly estimated that the costs of water operation and maintenance per ton is about 6 yuan,and it can save electricity cost by 60%,manual operation and maintenance cost by 75%,reduce the cost of water operation and maintenance per ton by more than 5 yuan,and obtain energy recovery income of about 1.3 million yuan per year?1000m³/d treatment capacity?.New ideas are provided for the upgrading of the sewage treatment system of China's railway system.