单级与二级BAF工艺除碳硝化效能的对比研究

在总曝气量、HRT、水温、进水水质相同的条件下,对比研究了单级(BAF C/N)和二级曝气生物液池(BAF C+N)处理生活污水的除碳硝化效能。结果表明,将除碳和硝化分级有利于提高BAF工艺的处理效能。分级后,C柱较C/N柱具有更高的COD去除容积负荷,且出水COD浓度稳定低于50 mg/L;二级BAF工艺出水NH4+-N浓度由单级BAF的5～12 mg/L降至5 mg/L以下,且N柱在pH<6.3时依然能够进行硝化;N柱中下部具有较高的微生物活性,平均比耗氧速率为32 mg O2/(g VAS·h)。二级BAF中C柱的反冲洗周期和强度与单级BAF相同,而N柱的反冲洗周期则延长至5～7 d,能够降低反冲洗能耗和用水量。

Comparative study of COD removal and nitrification efficiencies in single and two-stage BAF processes

In order to investigate COD removal and nitrification efficiencies in single(C/N) and two-stage BAF(C+N) processes for treating domestic wastewater,two parallel operated BAF processes were carried out under the same aeration rate,HRT,temperature and influent wastewater quality.The results showed that the separation of COD removal and nitrification led to higher treatment performance than single-stage BAF process.BAF C had higher organic removal loading rate than BAF C/N,and the effluent COD concentration was stably lower than 50 mg/L.The effluent NH+4-N concentration of BAF C/N and BAF C+N processes were 5～12 mg/L and lower than 5 mg/L,respectively,and nitrification occurred in BAF N at pH<6.3.The lower part of BAF N had highly microbial activity,the average specific oxygen uptake rate(SOUR) was 32 mg O2/(g VAS·h).Backwash of BAF C was the same as BAF C/N,while the backwash intervals of BAF N was extended to 5～7 days,which may reduce the energy and water consumption.