Study On The Anaerobic Sludge Granulation On Treating Piggery Wastewater In IC Reactor

The modern culture techniques boosted the development oflivestock cultivation on a large scale to high quality and benefit, and make ithighly specialized. On the other hand, a mass of wastewater was emitted fromlivestock farms without treatment and polluted environment badly. So, theurgent affairs are to settle the problem of wastewater treatment. Livestockwastewater treatment is a quite complicated process. In the process, ananaerobic bio-treatment technique is arranged as pretreatment cell. Thetechnique has several merits, such as reclaiming biogas and degradation of mostof organic contamination, which has been used generally by the livestockfarms. Anaerobic bio-treatment technique has a centuries-old history, but it isdeveloped slowly before the high-benefit anaerobic reactors were prepared,such as UASB reactor,IC reactor. Such reactors have a common characteristic,that is anaerobic granular sludge can be formed in them, which increase thequantity of microorganism and sludge retention time by a long way, so theorganic load rate (OLR) of them is improved enormously. Comparing withUASB reactor, IC reactor has a higher OLR, but it was only used to treatseveral kind of industrial wastewater because PAQUES Company, thedeveloper of IC reactor, kept it secretly. So, say nothing of livestockwastewater. 121河南农业大学博士学位论文 For exploring IC reactor to treat livestock wastewater, the paper studiedthe cultivation of granular sludge in IC reactor using piggery wastewater assubstrate. (1) Studied on the earlier technological conditions of treating piggerywastewater in the IC reactor. By the study on the air replacement device andvalidating on the IC reactor, the results indicated that sludge was cultured fast,methane content of biogas is high when the COD concentration of inflow,alkalinity and influence of inoculum of sludge is 2000mg/L, 1200mg/L and15mgVSS/L respectively, which is profit for the start-up of IC reactor. (2) The experiment of start-up of IC reactor was done by the two means offeeding material intermittently and continuously, which make clear that it isdifficult to form granular sludge by feeding material intermittently, but granularsludge can be formed at the two reactors by feeding material continuously. Atthe same time, it is found that the degree of formation of granular sludge ishigher in the IC reactor than UASB reactor. (3) It's showed in the experiments that the formation of granular sludgecan be divided into three stages: sludge taming, the growth of granular sludgeand the maturity of granular sludge. (4) The experiments under working conditions show that the IC reactorcan work at speed with low and high concentration, that the water-entering flowcan be enhanced properly with low concentration, but it need to be decreasedwith high concentration, that the reactor can function normally with thealkalinity from 1200 to 2500mg/L, but the raise of alkalinity can lower themethanogenic activity of sludge, and the alkalinity should be controlled under2000mg/L, and that the suspended substance concentration under 700mg/Ldoesn't have an effect on the function of reactor. (5) Through the observation of scanning electron microscope and 122河南农业大学博士学位论文transmission electron microscope of granular sludge, it's found thatMethanobacterium and Methanococcus are preponderant bacteria, and differentbacteria grow in different regions respectively with the character ofregionalization of growth. Filamentous bacteria can also be found on thesurface, which shows that there's relationship between the formation ofgranular sludge and the network function. Filamentous bacteria are not foundinside granular sludge, and Methanobacterium and Methanococcus arepreponderant bacteria, either symbiotically or in different regions. (6) In the paper we use the concept of the spec...