Study On The Purication Of Reservior Water From Yellow River With The Combined Rocess Of Traditional Technology And Ultrafiltration

The paper mainly studied the purification of the reservior water from YellowRiver with the combined process of traditional treatment process and ultrafiltration.As the raw water from southern-suburb reservior in Dongying city had two typicalwater quality characteristics of low temperature and low turbidity in winter andhigh algae in summer, the research on the integrated process ofcoagulation-sedimentation+ultrafiltration and coagulation-sedimentation+PAC-UF and were respectively carried out.During the study of coagulation-sedimentation+UF process treating thewater with characteristics of high algae water in summer, the experiments such asraw water coagulation、 the influence of coagulant types and dosage toultrafiltration treating high algae water were carried out. The best quantity ofcoagulant was determined by the raw water coagulation test. The best quantity ofpolymeric aluminum chloride（as Al2O3）、Al2(SO4)3and FeCl3is3mg/L、6mg/Land12mg/L respectively. The results of the experiment of the influence ofcoagulant types to ultrafiltration treating high algae water showed that coagulanttypes have no effect on the removal efficiency of turbidity、chroma and algae, andthe turbidity、chroma and algae of ultrafiltration output water is under0.08NTU、5degrees and12500per liter respectively. The result of removal efficiency oforganics showed that polymeric aluminum chloride is the best, the next is FeCl3,Al2(SO4)3is the worst. CODMnand UV254total removal rate for the integratedprocess is45.8and41.7percentage respectively with polymeric aluminumchloride dosage of3mg/L. The result of membrane fouling control showed that theTMP growth rate of polymeric aluminum chloride is the slowest. After24h, theTMP increased by6.4kPa with polymeric aluminum chloride dosage of3mg/L.The results of the experiment of the influence of coagulant dosages toultrafiltration treating high algae water showed that coagulant dosages have noeffect on the removal efficiency of turbidity and algae, and the turbidity and algaeof ultrafiltration output water is under0.08NTU and12500per liter respectively. The result of removal efficiency of organics showed that the high dosage (6mg/L)is the best, and CODMnand UV254total removal rate is45.8and41.7percentagerespectively. The dosage of residual aluminum in ultrafiltration output water didnot come up to the China’s drinking water standard with the high dosage, and thelow dosage and the best dosage are good for controlling the dosage of residualaluminum in output water. The result of membrane fouling control showed that theTMP growth rate of high dosage is the slowest. After24h, the TMP increased by3.7kPa with polymeric aluminum chloride dosage of6mg/L.During the study of coagulation-sedimentation+PAC-UF process treating thewater with chacarteristic of low temprature and low turbidity in winter, theexperiments such as PAC absorption effectiveness test、coagulation test andcoagulation-sedimentation+PAC-UF test were carried out. The results of PACabsorption effectiveness test and coagulation test showed that the best runningparameters of coagulation-sedimentation+PAC-UF process were PAC dosage of15~20mg/L、coagulant dosage of4mg/L and PAC contact time of10min whentreating low temperature and low turbidity water in winter. The results of theexperiment of coagulation-sedimentation+PAC-UF process showed that theintegrated process could limite the turbidity of effluent under0.08NTU with theremoval rate more than98%, that the integrated process could arise the averageCODMnand UV254removal rate by22and8.5percentage respectively with PACdosage of20mg/L. After96h, the TMP of PAC-UF process increased by40.2kPa,8kPa less than the TMP of UF process.It is customary to think of four general causes of membrane fouling:concentration polarization、cake layer、film hole narrows and internal fouling ofmembrane. The influence of pollutants accumulated in membrane pool tomembrane fouling showed that extending the emptying cycle could strengthen theeffects of pollutants removal, but it increased membrane fouling and energyconsumption under the hydraulic backwash condition. Extending the emptyingcycle weaken the effects of pollutants removal and had no obviously effect onmembrane fouling under the air-water backwash condition. The influence of different membrane flux to membrane fouling concluded that membrane flux had ahuge effect on the growth rate of trans-membrane pressure. After144h, thetrans-membrane pressures of10L/m2h、20L/m2h and30L/m2h were4、21.8and25.5kPa respectively.