Research On Cultivation And Performance Of Aerobic Granular Sludge With Carrier

The technology of aerobic granules is using in the biochemical treatment of waste water as a new technology. Microorganisms become bio-particles through self-aggregated under certain selection pressures, and they have compact structure, good settling ability also a excellent ability of biological treatment.In this study,aerobic granules with carrier were successfully cultivated through adding AC or AC/PPY grain together with inoculated sludge. They have compact structure, good settling ability and excellent removal effect of N. This study detailed investigated the process of floc sludge-small particles-ripe aerobic granules-storage-disintegration-recovery and the feasibility in low C/N wastewater treatment. The main experimental results are as follows:(1) Cultivation and performance of AC/aerobic Granular Sludge. Add AC with the size between830-1700μm and sludge in the SBAR (Rl).The concentration of COD is400mg/L and stepwise increased NH4+-N from50mg/L to100mg/L. On the15th day, there is activated sludge membrane on the surface of AC; on the thirtieth day, small particles appear but have a loose structure; on the sixtieth days, mature granules are cultivated. The respective COD, NH4+-N and TN removal efficiency reached80%-90%,99%,80%.(2) Cultivation and performance of AC/PPY aerobic Granular Sludge. Add AC-PPY prepared by chemical oxidation method with the size between830-1700μm and sludge in the SBAR(R2). On the15th day, there is activated sludge membrane on the surface of AC/PPY but thinner than the one on the surface of AC at the same time; on the thirtieth day, smaller particles then those in Rl appear but have a loose structure; on the sixtieth days, mature granules are cultivated. NH4+-N and TN removal efficiency reached99%and82%.At the beginning, PPY membrane covers the hole of AC, and the granulations is delayed. The influence gets smaller when the granules become mature.(3)The storage and evolution of AC aerobic Granular Sludge. Observe the morphology and properties of the granules after a long-term storage of12months in the condition of4degrees:the colour of the granules become gray black from pale brown and the microbial activity decreas. After4days’recovery, the colour turns back:7days later. COD removal efficiency reached90%;11days later, NH4+-N removal efficiency reached99%;14days later. TN removal efficiency reached75%.Compared with traditional active sludge. AC/aerobic granular sludge has a shorter recovery time. This means AC is benefit to enhance the granules" stability and strength and also the microbial activity.