Research on Improving Urban River Micro-Ecological Environment by Combining CaO2 with Microorganisms

Improving the micro-ecological environment in urban rivers is crucial for preventing river black and odorous phenomena. This study examined the effectiveness of using CaO2 and microorganisms in treating urban rivers with black and odorous phenomena. The results indicated that this method had a high removal rate for ammonia nitrogen and COD in the overlying water, reaching 95.1% and 72.1%, respectively, and the dissolved oxygen concentration increased to 6.5 mg/L. The overall water quality met Class III water standards, and the sediment’s removal rates of AVS and organic matter were 87.4% and 33.3%, respectively, reducing the potential risk of black and odorous phenomena in the water. Amplicon sequencing analysis showed that the combination of CaO2 and microorganisms improved the micro-ecological environment of the sediment by increasing dissolved oxygen concentration, regulating redox potential, promoting oxidation of organic matter, ammonia nitrogen, and sulfides, and inhibiting microorganisms that cause black and odorous phenomena.