Experiment And Application Studies On Upgrading And Retrofitting Of Wastewater Treatment Plant Based On MBBR Technics

Jining wastewater treatment plant was studied in this paper.For the problem of the low removal efficiency of nitrogen and phosphorus,the experiment of MBBR?Moving Bed Biofilm Reactor?and advanced treatment was conducted,then the best optimum design of operation parameters could be determined.The productive application experiment was conducted according to the results of the MBBR and lab-scale experiment for improving the effluent quality of the wastewater plant.The experiment analyzed the problems existing in the original process and the removal characteristics of main pollutant COD,BOD,TN,NH₄⁺-N,TP and SS.It was necessary to reach the standard level of A ascension through new technology.The MBBR experiment showed that the effluent quality declined with the increase of influent water organic load.When the organic load was 0.198?gCOD/gMLSS.d?,the effluent index?COD,TN,NH₄⁺-N,TP and SS?concentration of the MBBR system was 58 mg/L,12.3 mg/L,2.2 mg/L,2.3 mg/L,18.8 mg/L.The denitrification ability of the system improved significantly.The MBBR improved the nitrification capacity of the system and the adjustment of aeration status in the end of aerobic zone reduced the amount of dissolved oxygen in the reflux.Through the experiment of coagulation and disinfection,the type and quantity of coagulant and disinfectant chemical were determined.The results showed that the optimal method was using FeCl₃?50ppm?and NaClO?10ppm?.The effluent concentration of COD and TP could reduce to 42 mg/L and 0.18 mg/L.The average concentration of SS reduced to 6.01 mg/L after cloth filter,and the water quality stabilizes to the grade A standard.The results of the productive application of MBBR showed that th effluent concentration of every index?COD,TN,NH₄⁺-N,TP and SS?was 51.5 mg/L,11.2mg/L,1.7 mg/L,2.03 mg/L,17.1 mg/L and the removal efficiency improved by8.3%,13.3%,13.9%,9.5%and 13.9%respectively compared with the original process.The quantity of coagulant and disinfectant chemical were 50ppmFeCl₃,2ppmPAM and 10ppmNaClO.After the depth processing unit,the average concentration of every index?COD,TN,NH₄⁺-N,TP and SS?decreased to 32.6mg/L,11.2 mg/L,1.7 mg/L,0.23 mg/L and 2.33 mg/L.The performance of the sewage treatment plant was improved.The annual operating cost of this project is 34.24 million yuan per year,the total annual cost is 43.19 million yuan per year,the cost of water production is 0.59yuan per ton,and the operating cost is 0.47 yuan per ton.