The Study On Treating High Density Sulfate Organic Wastewater With Two-stage ABR+Flocculation+A/O Process

One of Jiangxi Pharmaceutical Company brings about high density sulfate organic wastewater during the production of Lincomycin and chongcao powder. The wastewater contains sulfate,NH4+-N and COD with high concentration and high pH,temperature and color, it is difficult to be treated for using the conventional biochemical and chemical methods. Using a two-phase anaerobic+chemical sedimentation+A/O Process to deal with the wastewater, and controlling the condition to make the acid—producing bacteria become the preponderant bacteria in the ABR1 (anaerobic reactor), the sulfate reducting bacteria in the ABR1deoxidize the S042-into sulfide, which is to reach the aim of removing the S042-. Afrer adding FeCl2, PAC, PAM it will produce FeCl2 precipitation which can be be removed in the sedimentation tank. As the COD concentration are still high and containing plenty of sulfur compounds after the above processes, we adopt two-phase anaerobic reactor to remove COD.This subject adopts two—phase anaerobic+ chemical sedimentation+A/0 process for the sulfateorganic wastewater of high concentration, through practical project debugging and stable operation, the results show that:(1)In the starting phase, domesticate sewage sludge through gradually increasing the concentration of the influent sulfate and COD concentration in the ABR1 reactor. The concentration of the influent water sulfate and COD in the ABR1 reactor goes from 600mg/L,4500mg/L to 1300mg/L,15000mg/L. As seed sludge from the old wastewater station and in summer, it can shorten the domestication time. It took only 90 days from the beginning.By making sludge acclimation. The removal rate of SO42-and COD goes up to 90%and30% respectively. The load rate of sulfate is 0.58kgS042-/(m3.d).(2) Sulfide removal results:insoluble ferrous Fe2+ salt precipitation is formed in that the sulphide of FeCl2 reacts withFe2+ salt.FeS is too small to precipitate, Through adding PAC (PAC) and PAM (Polyethylene acrylamide), sedimentation effect. is improved largelly. FeCl2, PAC, PAM concentrations were:2.5%,2%,0.1%, adding the ratio of 500L/h:100 L/h:30 L/h, sulfide removal efficiency of 85%. (3)The starting phase of ABR2:domesticate sewage sludge through gradually increasing the concentration of the COD concentration in the ABR2reactor. The concentration of the influent water COD in the ABR2 reactor goes from 6000mg/ L to 15000mg/L. Starting the water flow at the beginning of 8 m3/h. COD volume load:1.8 kg COD/m3.d. Because debugging is now summer and seed sludge from the old wastewater station, the temperature is more appropriate, greatly reduce the sludge acclimation time, it took 90days. The ABR2 reactor granular sludge were successfully cultured, As a result COD removal rate reached 67.7%.(4) During stablestage:water influent sulfate concentration is 1300 mg/L and COD concentration is 15000 mg/L. At the same time pH is 6.8, sulfate removal rate stabilized at 90% and COD removal rate keeped above 30%.(5)The organic load of ABR2 reactor is 1.8 kgCOD/(m3.d), HRT of ABR1 reactor is 3.25d,Average influent concentration of COD is 6300mg/L and pH value is 7.4, the alkalinity is 1300mg/L(by CaCO3). The COD removal rate reachs 70%.(6)In the stablestage, both ABR1and ABR2reactor are formed 0.15—0.22 mmgranular sludge. It has high removal rate of sulfate and COD in the high concentration sulfate organic wastewater by two-phase anaerobic progress, at the same time it have high efficiency(7) In the starting phase of A/O:domesticate sewage sludge through gradually increasing the concentration of the COD concentration and aeration in the A/O reactor.After five days, CODdrops form 2000mg/L to 400 mg/L through continuous aeration. After seven days again, CODdrops form400mg/L to 280 mg/L through continuous aeration.during the time SV30 is 25%,DO is 2.5 mg/L and MLLS is 4000 mg/L.The COD and NH4+-N removal rate reaches 90% and 89% respectively.