采用自行设计的新型结构A/O生物流化床处理食品加工废水,处理规模为800m^3/d。当进水COD、NH3-N、SS和油浓度分别为957.6~6841.4、11.5~42.3、50.3~982.5和6.2~22.7mg/L时,处理出水水质能达到GB8978-1996中的一级排放标准。A段新型射流曝气内循环厌氧流化床通过生物气和废水共同循环,实现了废水与污泥充分混合,在回流比为1.2、HRT为24h、容积负荷为2.06~3.96kg/(m^3·d)的条件下,可去除约80%的COD,最高产气量达到180.5m^3/d。0段新型卧流式好氧三相流化床在高长和高宽比为0.47和0.64时,较好地实现了流态化。此外,流化床内高效三相分离区的成功设计,维持了反应器内污泥的高浓度,为高效率、低能耗的稳定运行提供了保障。
The self-designed new A/O biological fluidized bed was used to treat food processing wastewater. The designed capacity is 800 m^3/d. When the influent concentrations of COD, NH3 - N, SS and oil are 957.6 mg/L to 6 841.4 mg/L, 11.5 mg/L to 42.3 mg/L, 50.3 mg/L to 982.5 mg/L and 6.2 mg/L to 22.7 mg/L respectively, the obtained effluent quality can meet the class I criteria of Integrated Wastewater Discharge Standard (GB 8978 -1996). Biogas and wastewater are co-recycled in the new jet aeration internal-loop anaerobic fluidized bed, the wastewater and anaerobic sludge are mixed enough in it. When the recycle ratio, HRT and average volume loading are 1.2, 24 h and 2.06 kg/( m^3· d)to 3.96 kg/( m^3· d)respectively, the COD removal rate and the largest biogas production can reach about 80% and 180.5 m^3/d respectively. In the new horizontal aerobic three-phase fluidized bed, the ratio of height to length and width is only designed at 0.47 and 0.64, but there is good fluidization effect in this reactor. Otherwise, the three-phase separator is designed successfully so that the high biomass concentration is kept in the two new reactors, which ensures high efficiency and low energy consumption of industrial organic wastewater treatment.