Study On Enhanced General Treatment Process And Emergency Treatment Experiment For Souce Water In Wan Jiazhai Reservoir

The raw water of Huyan Water Plant comes from Wanjiazhai Reservoir in theupper course of the Yellow River, water quality changes a lot thoughout the year.Organic pollution is a potential threat in summer and low temperature and turbidity is aproblem in winter. Currently, the process is unable to resist water quality changes, thedistribution of water is not uniform, the effect of coagulation and filter is notsatisfactory, backwash can’t work well, which make the product water quality unstableand the process be unless to low temperature and turbidity water. Without emergencymeasure and advanced treatment technology, Huyan Water Plant has less ability toresits unexpected organic pollution. In the paper Huyan Water Plant is studied as theresearch object, through checking the process parameters, analyzing raw water quality,carrying out laboratory test and pilot test. Against questions of coagulation and filterprocess, enhanced coagulation and filer is studied. Emergency control measures areresearched for potential unexpected organic pollution.Through laboratory test, the optimal kinetic parameter is decided. Rapid mixingprocess is350r/min and0.5min, Level1of flocculation process is120r/min and5min,Level2of flocculation process is80r/min and10min. The best coagulant is PAS anddose is20mg/L, the best coagulant aid is anionic PAM. The combination which makesthe effect of coagulation best is15mg/L of PAS and0.5mg/L of anionic PAM.Through pilot test, PAS is the best coagulant and the better dose of PAS is17.5mg/L-22.5mg/L. Adding coagulant aid is effective when coagulation begins2-6min, which makes the turbidity of sedimentation tank effluent low than1NTU.When coagulant is2#PAC and PAS, the optimal dose of PAM is0.9mg/L and0.5mg/L,the optimal time of PAM is4min and2min after coagulant is added. In the resistance towater load experiment, when flow rate is1.3m3/h, turbidity is more than1NTU addingPAC, turbidity is more than0.9NTU adding PAS or PAC and PAM, turbidity is0.851NTU adding PAS and PAM.Through enhanced filter test, when filtration rate is8m/h, the product water of3#filtration column is the best. When filtration rate is10m/h and12m/h, the periodicquantity of water produce of2#and3#filtration column is maximum. Throughbackwash test, the optimal way of backwash is decided, air washing process is 15L/s m2and2min, air water washing process is4L/s m2and4min, water washingprocess is8L/s m2and6min.Through the survey of natural and social environment in the Fenhe Reservoirsurrounding, Phenol, Atrazine and Chlorothalonil are potentially major organicpollution. The Freundlich adsorption isotherm of phenol, Atrazine and Chlorothalonilare qe=0.0121×Ce0.3752, qe=0.0227×Ce0.4555, qe=0.1032×Ce0.6801. The rate and capacityof adsorption are Chlorothalonil> Atrazine> Phenol. About9%of phenol,16%ofAtrazine and80%of Chlorothalonil can be removed by enhanced coagulation. Butenhanced coagulation cannot make treated water up to standard.Through the emergency control test, PAC adsorption and enhanced coagulation incombination is effective on the removal of Phenol, Atrazine and Chlorothalonil. Forthe initial concentration of0.1mg/L of Phenol, Atrazine and Chlorothalonil, dosage of80mg/L,60mg/L and20mg/L of PAC and20mg/L coagulant can reach more than98%,98%and95%removal efficiency, and make treated water up to standard.The paper proposed the dynamics control method and the optimal combinatiaonof coagulants and coagulant aids for Huyan Water Plant and provided scientific basisand technical reference for improving efficiency of coagulation-sedimentation process.The study on the ratio of the filter layer and the way of backwash provided theoreticalfoundation for improving product water quality of filter, enhancing filtration processstability, improving the effect of backwash. With emergancy control measuresproposed, Huyan Water Plant can take action for unexpected low concentration organicpollution, reduce threats for the water supply security and decrease the cost foremergency measures. Research results can be replicated in north-central China andprovide technical support for the surface water treatment plants which treat reservoirwater diverted from the Yellow River.