用抑制常数法探讨七种离子对活性污泥的毒性

INQUISITION OF TOXICITY OF IONS IN ACTIVATED SLUDGE WITH INHIBITION COEFFICIENT

本实验用溶解氧电极测定七种抑制剂对污泥溶解氧(DO)的影响,用Pascal程序计算抑制常数Ki,判断其对污泥的毒性。实验结果,CN^-、Cu^(2+)、Ni^(2+)、Cr^(6+)、Zn^(2+),Cd^(2+)、Pb^(2+)的Ki值分别为0.06、5.86、22.79、75.11、81.02、163.05、207.35(mg/L)。证明Ki值不受污泥浓度影响,基质浓度在200～400mg/L范围内也不影响Ki值。

In this work, a method of measurement of inhibition cceffioient, Ki, of metals within activated sludge has been propesed. It can be used in laboratcry and water treatment plant for the purpose of determination of heavy metal toxicity on biological water treatment efficiency.In this method, the respiration rate of activatel sludge in present of heavy metal was gotten with dissolved oxygen values. The values of Ki for Copper Cu^(2+), Nickel Ni^(2+), Cadmium Cd^(++), Lead Pb^(2+), Chromium Cr^(6+), Cyanide CN^-, and Znic Zn^(2+) were determined, respetively.The toxci order of these ions were CN^->Cu^(2+)>Ni^(2+)>Cr^(6+)>Zn^(2+)>Cd^(2+)<Pb^(2+) The effects of substrate concentration and MLSS on Ki were investigated. As substrate concentration was beyond 200 mgL^(-1), the change of it would not affect the value of Ki, and nor do the change of MLSS.