Cultivation Of Aerobic Granule And Its Application In Treatment Of Industrial Wastewater

Aerobic granulation for the treatment of variable and changeable industrial wastewater was investigated. The batch biosorption of Malachite green (MG) onto aerobic granule was conducted to evaluate the feasibility of aerobic granule as a biosobent. Aerobic granulation for 2,4-dichlorophenol (2,4-DCP) biodegradation with glocuse as a cosubstrate was examined to explore the 2,4-DCP biodegradation property and mechanism. Aerobic granulation with brewery wastewater was detemined to predict its full-scale application in industrial wastewater treatment.The result shows that aerobic granules cultivated with synthetic wastewater exhibit large capacity for the biosorption of MG from aqueous solutions, which is 82 mg/g SS at the initial concentration of 80 mg/L. pH value has great effect on biosorption process.The increasing organic loadings and decreasing of settling time resulted in the selective pressure to enhance the formation of granular sludge. The aerobic granules had a clearly defined shape and appearance, demonstrated high settling velocities resulting in good liquid separation, high biomass retention and ability to withstand COD_cr and 2, 4-DCP. The Mixed Liquid Suspended Solids (MLSS) and the Sludge Volumetric Index (SVI) were about 4.8 g/L and about 23 mL/g, respectively. The removal efficiency of COD_Cr and 2, 4-DCP both reached 90% .The key step of the biodegradation of 2,4-DCP was dechlorination. The biodegradation kinetics was also investigated. Results showed that the presence of 2,4-DCP at the concentration of 105 mg/L inhibited the biodegradation rate of 2,4-DCP and the inhibition increased with the increase of 2,4-DCP concentration.After 9-week operation, stable granules with sizes of 2-7 mm were obtained with brewery wastewater. With the granulation, the SVI value decreased from 87.5 to 32 mL/g. The granule had an excellent settling ability with the settling velocity over 91 m/h. Aerobic granule exhibited good performance in the organics and nitrogen removal from brewery wastewater. After granulation, high and stable removal efficiencies of 88.7% COD_t, 88.9% NH₄⁺-N were achieved at the volumetricexchange ratio of 50% and cycle duration of 6 h. The average COD_t and COD_s of theeffluent were 212 and 134 mg/L, respectively, and the average effluent ammoniumconcentration was less than 14.4 mg/L.