A Study On The Characteristics Of Saliniferous Organic Wastewater Treated By Aerobic Granular Sludge

Aerobic granular sludge is a kind of microbial polymer formed by self-aggregate under aerobic conditions. Aerobic granular sludge has good performance on settling, high biomass concentration, good hydraulic intensity and compact microbial structure. Besides, the micro-biocommunity in granular sludge is diversified, which can generate more stable ecosystem. Under the high organic loading, it has the biological activity which can degrade the high-concentrated organic wastewater, and its capacity of resisting disturbance and self-recovery adjustment is excellent. The promising technology of aerobic granules has found many applications in domestic, phenol, and brewery wastewater treatment. However, there is little research about its application in dealing with saline wastewater. The objective of this work is to evaluate the decontaminating efficacy of aerobic granular sludge in different salinity wastewater and analyze the factors that impact its decontaminating efficacy.Aerobic granular sludge was applied to dispose the high salinity organic wastewater in this experiment by SBR. Seed sludge obtained from Xi'an dengjiacun sewage plant was domesticated under aerobic conditions in the reactor, and finally we get the aerobic granular sludge. The experiment lasted a total of 120 days. The water sample was collected timely and the water quality parameters was measured which include: ammonia nitrogen, nitric nitrogen, effluent SS, pH, the total organic acid, the granule size distributes and density. By the analysis of parameters to study the characteristics of disposing the high salinity organic wastewater in SBR, we try to find various factors which affect the decontaminating efficacy of the high salinity organic wastewaterResult shows that: (1) Under the 5% salinity condition, ammonia nitrogen elimination is not satisfactory. Under the 1% and 2.5% salinity conditions, the biological community in sludge and the structure of particles are conducive to elimination of ammonia nitrogen, and more than 90% of ammonia nitrogen can be eliminated. (2) Under the 1% salinity condition, the effluent SS is the lowest. Under the 5% and 2.5% salinity conditions, the effluent SS is higher. That is because the high salinity causes the disintegration or expansion of particle, which eventually lead to the hollow of the granular internal structure. (3) Due to the feature of salt-tolerant bacteria growing and the changes of particles' structure, 5% salinity leads to the alkaline of water. Because of organic acids and the balance of carbon dioxide in water, the water presents weak acidity under the 1% and 2.5% salinity condition. (4) With the increase of salinity, the rate of oxygen consumption becomes slower and slower and the effectiveness of ammonia nitrogen elimination becomes worse and worse. The rising of ph results in the water's weak alkaline and the effluent SS is growing continuously and the effluent water quality gets worse.