Study on the treatment effect of combined artificial wetland water quality purification technology on slightly polluted rivers

To further strengthen the governance and restoration of the water ecological environment in the watershed and build a strong ecological barrier in the upper reaches of the Yangtze and Yellow Rivers, the combination treatment technology of “pre-treatment sedimentation+vertical subsurface flow artificial wetland+surface flow artificial wetland+oxidation pond” was used to purify the inferior Class V water body of a slightly polluted tributary of the Yangtze River system in Sichuan Province. Continuous monitoring was conducted for two years, and the results showed that: The entire treatment system has a good purification and treatment effect on pollutants, with the removal rates of ammonia nitrogen, total nitrogen, total phosphorus, and CODMn being 85.57%, 74.03%, 57.42%, and 40.47%, respectively. The treated water quality meets the Class V-II standard for surface water; There are differences in the treatment efficiency of several treatment units, with the vertical flow wetland treatment efficiency and contribution significantly higher than the other three, and the oxidation pond treatment effect is the worst; The removal rate is influenced by a combination of factors such as temperature, influent concentration, and influent volume.