Accelerating Aerobic Granulation By Adding Waste Powders

Sludge powders grinded of waste sludge produced by municipal wastewater treatment plant and crystal powders made of solid waste sludge from crystal production process were added in SBR respectively to accelerate the forming and stability of aerobic granules.The granulation process in P-SBR had waste sludge powders(the size of powders is about20～250μm) addition in start-up was obviously faster than the conventional SBR15days, moreover, the settleability of granules in P-SBR (with SVI of51mL/g) was better than the conventional SBR(with SVI of73mL/g). When SBRs were inoculated with the activated sludge with filamentous, a mount of granules sludge were founded in P-SBRs had sludge powders addition in start-up after7days operation, the granules with mean size of400μm and SVI of35.5mL/g and41.5mL/g respectively were formed at30th day. However, filamentous were still dominated in the conventional SBR after30days, and SVI achieved highly to247mL/g. The elements of granule sludge were analysed by XRF and the results demonstrated that Al and Si elements were all deposited in granules, it could be presumed that the waste sludge powders were acted as the role of the nuclei to enhance biomass accumulated and attached on the surface of nuclei, and then seed up the forming of granule sludge. Adding Sludge powders to the up-continuous flow reactor, the granules with compact structure and better settleability were founded after5days operation, the SVI of sludge decreased from131mL/g to38.5mL/g.Sludge powders and crystal powders were added to SBRs to accelerate granulation, through compared experiments it was founded that the granulation process in P-SBRs were both faster than the conventional SBR, the granules were mainly in P-SBRs after9days operation, and SVI decreased to38.3mL/g and39.4mL/g respectively, the granules were stable after stopping adding powders.Through the compared experiments in SBRs and continuous flow, it showed that adding sludge powders and crystal powders was a simple and effective method to accelerate aerobic granulation.