前置反硝化生物滤池改进工艺处理水产养殖废水研究

Study on Improved Treatment of Aquaculture Wastewater by Pre-denitrification Biofilter

选用以竹丝为填料的缺氧生物滤池,并结合气升式内循环曝气生物滤池组成前置反硝化生物滤池改进工艺,研究其对低C/N比水产养殖废水中COD_(Mn)、NH_(4)^(+)-N、TN、抗生素等典型污染物的去除效率。结果表明:该改进工艺在水力负荷q=18 m^(3)/(m^(2)·d),A/O体积比为1.8,硝化液回流比为100%,气水比为6:1时,出水水质较好。上述工艺COD_(Mn)平均进水为8.00 mg/L、NH_(4)^(+)-N、TN的平均进水质量浓度分别为2.33、4.50 mg/L,平均去除率分别达到了43.11%、88.86%、84.67%,COD_(Mn)平均出水为4.55 mg/L,NH_(4)^(+)-N、TN平均出水质量浓度分别为0.26、0.69 mg/L,满足《地表水环境质量标准》(GB 3838-2002)III类标准。采用固相萃取—高效液相色谱法对抗生素去除效果进行研究发现,本改进工艺在不同季节对水产养殖废水中的磺胺甲噁唑(SMX)都有很高的去除效果。夏季系统对SMX的总去除率为99.39%,秋季系统对SMX的总去除率为93.85%。

An anoxic biofilter with bamboo silk as a filler was selected,and an improved process of pre-denitrification biofilter was combined with an airlift internal circulation aerated biological filter to study the removal efficiency of typical pollutants in low C/N ratio aquaculture wastewater,such as COD_(Mn),NH_(4)^(+)-N,TN and antibiotics.The results show that the improved process has a hydraulic load of q=18 m^(3)/(m^(2)·d),an A/O volume ratio of 1.8,a nitrifying liquid reflux ratio of 100%,and a gas-water ratio of 6:1.The average influent concentrations of COD_(Mn),NH_(4)^(+)-N,and TN in the above processes were 8.00 mg/L,2.33 mg/L,and 4.50 mg/L,and the average effluent concentrations were 4.55 mg/L,0.26 mg/L and 0.69 mg/L,the average removal rates reached 43.11%,88.86%and 84.67%.The effluent quality had met the Class III standard of Surface Water Environmental Quality Standard(GB 3838-2002).The solid phase extraction-high performance liquid chromatography(HPLC)method was used to study the antibiotic removal effect.It was found that the improved process had high removal effect on sulfamethoxazole(SMX)in aquaculture wastewater in different seasons.The total removal rate of SMX in the summer system was 99.39%,and the total removal rate of SMX in the autumn system was 93.85%.