Research On The Influence Of Heavy Metal Ions On The Activity Of Aerobic Activated Sludge

In the aerobic activated sludge wastewater treatment systems,the activity of microbe is the key factor to determine the efficiency of sewage treatment.In this paper, taking the sludge in the biochemical reaction pool of Fuxin Qing Yuan Wastewater Treatment Plant as inoculation sludge and adopting the intermittent drowning training method,the oxygen activated sludge which is stable and has a good biodegradability is obtained finally.The sequencing batch reactor experiment is used to study the effects of copper, zinc and nickel on the apparent yield, bio-adsorption degradation capacity,flocculation and settling performance,oxygen consumption rate and other aspects at different ion concentrations.And under the situation of two heavy metal ions co-existence and when the dosing concentrations are different, the interaction between the heavy metal ions is tested.The results of the experiment show that:When the concentrations of Cu2+,Zn2+ and Ni2+ are within 10mg/L,5mg/L and 10mg/L respectively and under the situation of two heavy metal ions co-existence,the total concentrations of Cu2+ and Zn2+,Cu2+ and Ni2+,Zn2+ and Ni2+ are within 5mg/L,5mg/L, 10mg/L respectively, it has a little influence on the apparent yield of sludge, the system can run stably.And the performance of nickel ions and zinc ions is relatively independent in the mixture.When the concentrations of Cu2+,Zn2+ and Ni2+ are within 5mg/L,10mg/L and 5mg/L respectively and under the situation of two heavy metal ions co-existence,the total concentrations of Cu2+ and Zn2+,Cu2+ and Ni2+,Zn2+ and Ni2 are within 5mg/L,3mg /L,3mg/L respectively, it has no effect on the removal rate of CODcr and MLSS can increase stably.If the concentrations are larger than these points,the system can not run normally. When the concentrations of Zn2+- Ni2+ are more than 1mg/L, it will have complete inhibition on respiration.When Cu2+ and Ni2+ are co-existence,there will be a synergistic inhibition on microbial respiration.If Zn2+ and Ni2+ are co-existence,the inhibition on the activity of microorganism is a little less than Ni2+ itself.