Study On The System Of Post-project Evaluation Using In The Municipal Wastewater Treatment Plant

Take the first phase of No.3 Wastewater Treatment Plant of Xi'an City as study object, this paper does systematic and objective analysis of construction goals, construction process,operating results, economic benefits, environmental and social effects, the aim is to summarize building experiences and lessons learned,at the same time proposes effective measures.By the study on the construction features and problems at this stage of Municipal Wastewater Treatment Plant(MWTP),this paper proposes post-project evaluation contents and gives a post-project evaluation index system of MWTP.The study results show that:The first phase of No.3 Wastewater Treatment Plant of Xi'an City conforms to national and local development objectives,makes correct and timely decisions,corresponds the construction procedure,controls construction costs within the total investment;This project defined reasonable deal scale but lower wastewater quality,the actual average wastewater quality is 1.7～2.1 times than the original design value;This project uses Orbal oxidation ditch process and has stable and substandard treatment effects, the average removal rates of COD, BOD5, NH3-N,TN, TP, SS is 93.6%,95.5%,84.9%,71.6%,94.4%,96.5%;Sludge produced by the project consistent with the standards of urban sewage sludge B mud,obtained compost for the best disposal of sludge;Operating costs of the project is 0.456 yuan per ton(excluding depreciation),with the ability to repay loans;The project didn't create adversely impact for environment,pollutant concentrations of Chan River decreased about 31%～40%.At the same time,by the running of this project,67 job was offered, improves the local living environment and encourages economic development;This project overall evaluation score is 2.742 points,the excellent post-evaluation results shows that this project was successfully implemented.