多级生物膜反应器分段进水方式对脱氮效能影响研究

提出多级生物膜反应器,考察了分段进水方式对反应器处理城镇污水生物脱氮效能的影响.结果表明,分段进水点的数量、流量分配及容积分配对反应器脱氮效能的影响显著,分段进水方式有效地提高了碳源利用率以及反应器脱氮效能.在水温为25℃左右,溶解氧为5mg·L~(-1),挂膜密度为30%,COD负荷为1.2 kg·m~(-3)·d~(-1),总氮负荷为0.22 kg·m~(-3)·d~(-1)的条件下,反应器分段进水方式采用第1级、第3级、第6级分段进水,容积分配比为2:3:4,流量分配比为2:2:1时,可使出水COD为38 mg·L~(-1),出水NH_4~+-N和TN的质量浓度分别为1.5 mg·L~(-1)和11.1 mg·L~(-1),去除率分别为80.8%,95.3%和69.2%,与单点进水方式相比TN去除率提高了8.4%.

INFLUENCE OF STEP-FEED STYLE ON DENITRIFICATION EFFICIENCY IN MULTISTAGE BIOFILM REACTOR

Influence of step-feed style on the efficiency of biological nitrogen removal was studied with multistage biofilm reactor in treating municipal wastewater.Results show that the number of step-feed points,flow distribution and volume distribution has significant effect on denitrification,and step-feed style can effectively improve the utilization ratio of carbon source,and then enhance the denitrification efficiency.Under temperature of 25 ℃,DO of 5 mg·L~(-1),biofilm density of 30%,COD loading of 1.2 kg·m~(-3)·d~(-1) and nitrogen loading of 0.22 kg·m~(-3)·d~ (-1),with wastewater fed in the 1st,3rd and 6th stages,flow distribution ratio of 2:2:1,and volume distribution is 2:3:4,the concentrations of COD,NH_4~+-N and TN in effluent are 38 mg·L~(-1),1.5 mg·L~(-1) and 11.1 mg·L~(-1) respectively,with removal effieiencies of 80.8%,95.3% and 69.2% respectively,and the removal efficiency of TN increasod by 8.4% compared with single point feed style.