盐度降低间歇曝气动态膜生物反应器净化水产养殖废水的效果

采用间歇曝气动态膜生物反应器(DMBR)处理不同盐度下的水产养殖废水,研究盐度对有机物降解和反硝化过程的影响。结果表明:当盐度在0～35g/L范围内,随着盐度的提高,由于盐度对微生物的抑制作用,在含盐条件下有机物降解和反硝化效率下降,间歇曝气动态膜生物反应器对水产养殖废水化学需氧量CODMn的去除率从89.5%下降到75.5%;出水总氮TN去除率从89.9%下降到74.4%。通过对有机物降解速率常数和反硝化速率常数的动力性模拟,CODMn降解速率常数和硝态氮NO3--N的降解速率常数随盐度的提高呈线性下降的趋势,其线性回归模型的决定系数分别为0.9838、0.9665。盐度对水产养殖废水反硝化过程的抑制作用要大于有机物降解过程。

Effects of salinity on treatment of aquaculture wastewater by dynamic membrane bioreactor with intermittent aeration

Salts are detrimental to biological treatment systems by causing plasmolysis and/or loss of cell activities, thereby the biological treatment of mariculture wastewater which with high sanity is difficult. A dynamic membrane bioreactor(DMBR) with intermittent aeration was used to treat aquaculture wastewater under different salinity. The effects of salinity on organic matter degradation and denitrification process were studied. The results show that when salinity increased from 0 to 35 g/L, the CODMn removal rate and TN removal rate by intermittent aeration dynamic membrane bioreactor for treating aquaculture wastewater reduced from 89.5% to 75.5% and from 89.9% to 74.4%, respectively. Because of the inhibition effect of salt on microorganism, the organic matter degradation and denitrification efficiency decreased in saliferous condition. Moreover, in the salt concentration of 0-35 g/L, the constants of CODMn and NO3--N reduction rate in the reactor decreased linearly with the improvement of salinity by kinetic analysis, and the coefficients of determination(r2) of linear regression models were 0.9838 and 0.9665, respectively. Salt has stronger inhibit effect on denitrification process than organic matter degradation process of aquaculture wastewater.