Experimental Studies On Coagulation+Ozone+Composite Filter For Advanced Treatment Of Reclaimed Water

The raw-water used in this experiment was the outwater in the wasterwater treatment plant of Jinan.O3/bio-composite filter was combined with coagulation and used for advanced treatment, the whole process fit coagulation, ozone oxidation, the active carbon-ceramics composite adsorption and biological effect together, it give full play to the strengths and synergies among all parties separately, which provides a new process for advanced treatment of renovated water.The comparative tests used FeCl3,Al(SO4)3 and PAFC, the results indicate, the best dosage of FeCl3,Al2(SO4)3 and PAFC are 50mg/L,50mg/L and 30mg/L respectively, the removal rate of turbidity,CODMn,UV254 and TP are respectively 65.3%,56.2%,34.5%,74.2%,75%,39.5%,19.8%,70.5%,69.4%,54%,29.1%,59.1%. The removal rate on CODMn and UV254 of PAFC and FeCl3 are higher than A12(SO4)3, so the best coagulant is PAFC.The dosage PAFC+PAM experiment compared with the single dosage of PAFC, adding PAM can make the flocculation effect obviously improved, the removal rate of turbidity, CODMn,UV254 and TP are respectively 75.7%,59.9%,37.9%,62.8%, the removal rate have been respectively increased by 6.3%,5.9%,8.8%,3.7%.The combined process of continuous operation experiment, when the average temperature,turbidity,CODMn and NH3-N of the renovated water are respectively 20℃,2.46NTU,6.35 mg/L and 2.03 mg/L,20-30min of empty bed contact time (EBCT), after 22 days, the removal rate of CODMn and NH3-N arrives at respectively 30% and 60%. EBCT has a great effect of the bio-composite filter. When extend the EBCT from 5min to 15min, turbidity removal rate from 45% to 61.5%,,CODMn removal rate from 39% to 47.9%, UV254 removal rate from 43.4% to 53.5%, NH3-N removal rate from 47.7% to 85%, NO2-N removal rate from 42.6% to 65%, then increase EBCT to 24.8min, the removal efficiency of pollutant remains basically unchanged, so 15min of EBCT is the optimal condition. Under the optimal condition of ozone dose of 5mg/L,15min of EBCT, the removal rate of turbidity,CODMn,UV254,NH3-N and NO2-N are respectively 75.1%,48%,54.6%,83.1% and 76.6%. The effluent of 50cm filter layer, the removal rate of turbidity,CODMn,UV254,NH3-N,NO2-N are respectively 49.1%,39.7%,48.5%,51.6% and 53.2%, the result shows that mainly concentrated above 50cm to complete, the microbiology decreases gradually with the flow direction.The research shows that, CODMn,NH3-N and TP are respectively 14.5mg/L,2.15mg/L and 0.38mg/L, after coagulation-03-bio-composite treatment process, the value of effluent CODMn,NH3-N and TP are respectively 3.1mg/L,0.37mg/L and 0.14mg/L, which can achieve surface water environment quality class III standards.