Aerobic Sludge Granulation For The Treatment Of Tannery Wastewater And The Control Of Granule Diameter

Tannery wastewater is one of the industrial wastewater of heavy pollution.It has not been reported that aerobic granular sludge was used for the treatment of tannery wastewater.In addition,oversized particle diameter of aerobic granular sludge is an important factor affecting its stability.The research aims to obtain aerobic granular sludge in the tannery wastewater and control the diameter of aerobic granular sludge.Aerobic granular sludge was successfully achieved for the treatment of tannery wastewater by orbital shaker as the preliminary test.The effluent COD and NH4+-N have reached the indirect discharge standards of tannery wastewater.The diameter of aerobic granular sludge was effectively controled by the sting.After 41 days' operation,the average diameter of aerobic granular sludge in the reactor without sting was 1100 ?m,and the average diameter of aerobic granular sludge in reactor with sting was 220?m.Aerobic granular sludge treating tannery wastewater was obtained in the SBR(The normal aeration device was used in R1 and the spiny aerationdevice was used in R2).Raw wastewater characteristics and SBR operation mode played an important role in aerobic sludge granulation.On day 65,the average diameter of granular sludge in R1 was 295 ?m,and the average diameter of granular sludge in R2 was 195 ?m.The MLSS of R1 and R2 were 2400mg/L and 2450mg/L;The SVI were 45mL/g and 50mL/g,respectively.COD and NH4+-N removal rate of the two reactors were about79% and 55%,the effluent has reached the indirect discharge standards of tannery wastewater.The spiny aeration device provided the aeration and constantly cut granular sludge to effectively control the particle diameter.It almost has no influence on the pollutant removal effect,but the granulation time was delayed.Inoculated sludge,aerobic granular sludge in R1 and R2 were analyzed by high-throughput metagenomics.It indicated that bacterial species of aerobic granular sludge and inoculated sludge were quite different,but the method control the diameter of granules with the spiny aeration device nearly had no effect on the bacterial species composition.Compared with inoculated sludge,the community richness of aerobic granular sludge became low and Proteobacteria has greatly increased.