Study on water quality safety and microbial diversity of water source reservoirs in Daqing City

Abstract

Water source reservoirs play a vital role in ensuring the drinking water safety. To explore the safety of water quality as the source of water supply projects in Daqing City, the chemical indexes of water quality in Daqing reservoir, Dongcheng reservoir and Hongqi reservoir were analyzed. The microbial diversity, community structure characteristics and Nitrogen metabolism functional bacteria were analyzed by high-throughput sequencing technology. Monitor the disinfection effect of three water source reservoirs after using sodium hypochlor disinfection. The results showed that, in 2021, the reservoirs water body was in a moderately eutrophic state, the main exceeding standard index was total nitrogen (TN) (1.25–1.57 mg/L). The microbial communities in water body and sediments were composed of 1048 genera. The microbial diversity in sediment was higher than that in water. Potential pathogenic microorganisms were detected in water and sediment samples. Although no coliform bacteria were detected, as a water source disinfection was also necessary. Redundancy analysis (RDA) showed that, the main water quality factors affecting microbial community structure in water samples were pH, in sediment samples were water temperature (WT), dissolved oxygen (DO), TN and total phosphorus (TP). Sodium hypochlorite has a good disinfection effect and can ensure the safety of drinking water.