The Energy Consumption Survey Analysis And Experimental Study Enhanced Coagulation Precipition Of Typical Municipal Wasterwater Treatment

In recent years, water environment pollution problem has become one of the keyproblems of our social economy rapid development in our country. It is generally believedthat solve the problem of water pollution of the environment of the most effective measure isto build sewage treatment plants, as more and more the number of urban sewage treatmentplant, operating costs is more and more prominent. High cost on the one hand cause increaseof our country’s energy crisis, on the other hand caused many urban sewage treatment plant"can built up, can’t afford to use", the emissions reduction effect of urban sewage treatmentplant can not get to play.This article choose typical urban sewage treatment plant of Tuhaiand Majia river basin as the research object,through investigating the energy consumptionpresent situation of sewage treatment plant, and put forward feasible strategy of energyconservation. On this basis, through the optimization study of sewage treatment plantcoagulation sedimentation unit and improve the pollutant removal effect of sewage treatmentplant, solving the problem of sewage treatment plant effluent standards.The research results of Tuhai and Majia river basin show that：（1）The energyconsumption of water per ton of urban sewage treatment plants in Tuhai and Majia river basinis0.258~0.372kW h//m3, the energy consumption of water per ton of urban sewagetreatment plants in north China in accordance with the administrative geographic division is0.285kW h/m3, the energy consumption of water per ton of urban sewage treatment plants inTuhai and Majia river basin is lower than0.285kW h//m3of urban sewage treatment plantswas25%, higher than0.285kW h//m3of urban sewage treatment plants was75%.（2）Theenergy consumption of water per ton of the second sewage treatment plant in LingxianCounty is0.372kW h/m3，is the higher sewage treatment plant of urban sewage treatmentplants in Tuhai and Majia river basin.The energy consumption of the blowing machine in thesecond sewage treatment plant in Lingxian County accounted for48.95%of the wholeprocess, the energy consumption of the sludge dewatering centrifuge accounted for12.87%,the energy consumption of the biological pool stirrer accounted for10.60%, the energyconsumption of the water pump accounted for6.18%, saving energy and reducingconsumption is the energy saving of the whole process of the sewage treatment plant, theenergy saving of the blowing machine is the key to the energy saving of the sewage treatmentplant.Test in coagulation sedimentation experiment results indicate that:（1）By coagulation sedimentation experiments of raw water of different pollutants concentration, suitable for thesecond sewage treatment plant in Lingxian County, the second pond water nature is the bestcoagulant PFS, in the second pond, the water under the condition of lower concentration, theoptinal dosage of PFS is20mg/L, in the second pond, the water under the condition of higherconcentration, the optinal dosage of PFS is30mg/L.（2）Under the water nature conditions ofthe second pond in the second sewage treatment plant in Lingxian County，the best pH valueof osing coagulant PFS to the removal effect of phosphorus is6.5，the best pH value of osingcoagulant PFS to the removal effect of CODCrand SS is8.5，as a result of the optinal dosageof PFS to the removal effect of CODCrand SS is higher than the optinal dosage of PFS to theremoval effect of phosphorus，so the best pH value of osing coagulant PFS under thecondition of this kind of water is8.5.（3）Coagulant PFS particles has a better removal effectof the water, the soluble refractory CODCrremoval effect is poorer, however, containantioxidant PFS use NaClO3and Na2S2O8oxidation, oxidate the of solubility of refractoryCODCr, cut down the CODCrcontent in the water. When the dosage of PFS is30mg/L, theconcentration of SCODcr adding the PFS (containing NaClO3) is35mg/L，the removal rateof SCODCris37.5%，is14.3%higher than the removal rate of adding the PFS，is10.7%higher than the removal rate of adding the PFS (containing Na2S2O8)，the best coagulant onthe removal effect of SCODCris PFS (containing NaClO3).（4）The best dosage of coagulantPFS (containing NaClO3) and coagulant aid PAM is30mg/L+0.4mg/L，when the static sinkis5minutes，the concentration of the coagulation effluent CODCr, TP, and SS, respectively is32mg/L,0.25mg/L,9mg/L, the removal rate of CODCr, TP and SS respectively is64.0%,88.3%,92.9%, the coagulation effect is the best.The research results of optimization of the mechanical stirring clarification pooloperation indicate that:（1）After adding fly ash into the mechanical stirring clarificationpool,the water becomes clear,floating floc in supernatant content decreases, and can reducethe dosage of PFS and PAM.（2）The optimal floc concentration of the center tube in themechanical stirring clarification pool，the average concentration of the effluent CODCr,NH4+-N,TN,TP and SS respectively is45.40mg/L,0.68mg/L,42.68mg/L,0.43mg/L,12mg/L, the removal rate of the effluent CODCr, NH4+-N,TN,TP and SS respectively is49.0%,60.0%,39.7%,85.8%,90.1%.