Treatment Of High Concentration Organic Wastewater Using Anaerobic-aerobic Process Based On Mobilized Microorganism

The paper studies on the feasibility of treatment of simulate high concentration organic wastewater and hogwash using anaerobic-aerobic process by immobilized microorganism. Organic matter which is difficult degradable could be converted easily degradable one in anaerobic degradation process, and produces bio-energy. Further treatment of wastewater is done in aerobic process. Combination of anaerobic and aerobic degradation process is availability of good economic and environmental benefits.The start-up, second start-up, acidification recovery process and the effluence factor of the high-efficiency anaerobic-aerobic biological filter are studied. COD removal rate, pH and gas production rate are monitored to evaluate effect of the reactor. The main results from these studies are summarized as following:1. The treatment of simulate high concentration organic wastewater is studied. The study shows that at the Temperature of 35℃, the start-up,second start-up and acidification recovery process of the reactor could be finished in 20,18,14 days, respectively, and the volumetric loading rate of the three processes are 5.6,6.0,5.76 kg COD/m3·d, respectively. With further treatment of three aerobic processes, COD of the wastewater is below 80 mg/L, and the value of pH is between 8 and 9.2. The influential factors of reaction such as flow amount, pH and temperature are investigated. Increasing the flow amount of anaerobic reactor, HRT drops from 17.65 h to 10.43 h, and volumetric loading rate increases from 6.53 kg COD/m3·d to 11.14 kg COD/m3·d, and the reactor is still on normal operation. At the condition of 35℃, HRT 15 h, COD 4800mg/L, pH 4.7, COD removal rate of anaerobic reactor is about 78%, and pH is between 6.8 and 7.2, and the gas production rate is 1.02-1.29 L/L·d. At the condition of 25℃, HRT 15 h, COD 2000mg/L, the highest COD removal rate of anaerobic reactor is 55%, and pH is between 6.7 and 7.2, and the gas production rate is 0.79-1.03 L/L·d.3. The treatment of hogwash by anaerobic-aerobic biological filter is studied. The study shows that at the condition of 35℃, HRT 15 h, the highest volumetric loading rate of the anaerobic reactor is 25.6kg COD/m3·d, the highest gas production rate is 4.28 L/L·d, and influential pH reaches a stable level of 6.7-7.2. With further treatment of three aerobic processes, the total COD removal rate is above 98%.4. SEM photos reveal that these are rich species of microorganisms. The main anaerobic microorganisms are methanogenic sarcina and methanogenic filamentous bacteria. The main aerobic microorganisms are filamentous bacteria and spherical bacteria, and there is a large number of protozoa.