| 内容提要: |
Ca(NO3)2 and CaO2 as ideal electron acceptors are widely used in black odorous waterbodies treatment. However, for the heavy contaminated black odorous waterbody, it is easy to cause black odorous rebound at low Ca(NO3)2 and CaO2 dosage, it is easy to cause secondary pollution at high Ca(NO3)2 and CaO2 dosage. Hence, the metabolic mechanism of black odorous sediment microorganisms on nitrogen and sulfur compounds was analyzed by adding Ca(NO3)2 first and then adding CaO2, and the dosage of Ca(NO3)2 and CaO2 according to the acidified volatile sulfides of the sediment. The result showed that, RN-O group ( which adding Ca(NO3)2 at 0th day and adding CaO2 at 12th day, and the Ca(NO3)2 receives electrons quantity equal to CaO2) was the best. The NO2-N of the overlying water did not accumulate significantly, NO3-N of the overlying water recovered to pre-repair levels on day 73 and degraded continuously at a rate of 0.15 mg·L-1·d-1, the NH4+-N of the overlying water was below the detection limit at 12th day and did not rebound after 117 days of remediation, the removal rate of the acid volatile sulfide (AVS) of the sediment was 95.12% at 52th day, and the microbial activity of the sediment growth rate was 189.62%, and the overlying water SO42- increased 46.90 mg·L-1 compared with the control group (Rc) on day 117. The main reason may be that the activity of sulfate-reducing bacteria was inhibited and the activity of sulfur oxidizing bacteria was increased after remediation. Amplicon sequencing analysis showed that the abundance of Bradyrhizobium、Bosea、Rhodobacter and Pseudomonas which were sulfur-oxidizing bacteria were higher than that of Rc. The abundance of syntrophus which was sulfate-reducing bacteria decreased by 0.97% compared with Rc. The result of principal component analysis further verified that the improvement of microbial activity in the sediment after remediation was related to the increased abundance of the eliminating black odorous microorganisms. |