Comparisons in concentrations of chlorine compounds in urban section of nanfeihe river before and after COVID-19 epidemic

ABSTRACT

The spread of COVID-19 epidemic in early 2020 has led to the widespread use of medical disinfectants, which will inevitably impact the ecological balance of natural water environment. Based on the data collection, field investigation and sampling and analysis, the main disinfectant types, toxicity and their distribution characteristics in Nanfeihe River, an urban river in Hefei City, Anhui Province were analyzed and studied, with the emphasis on the impact on water environment and aquatic ecosystem. The results showed that the most widely used disinfectant is chlorine containing disinfectant in the COVID-19 epidemic, and the total amount of the disinfectants and its by-products as calculated by total chlorine in the urban section of the River is 5.52-48.7g/L, which is significantly higher than the measured value during non COVID-19 epidemic period. It shows that the use of chlorine containing disinfectants during the epidemic has caused residues in urban water. In addition, the sampling points near the effluent of sewage treatment plant and rainwater discharge had significantly higher chlorine compounds, as compared with other points, indicating the ways of the disinfectant and its by-products entering water environment mainly including effluent discharge from sewage treatment plants and non-point source pollution caused by urban surface rainwater runoff. In order to reduce or eliminate the adverse effects of use of disinfectants on the urban water environment and aquatic ecological health, source control, process reduction, and terminal treatment, as well as supervision of the whole process of plant-network-river integration should be considered in future work.