The Environmental Impact And Emergency Countermeasures Of A Sudden Surface Water Pollution Accident

With the rapid industrial and agricultural development in our country, kinds of sudden water pollution accidents occur frequently, so the resulting environmental problems cannot be ignored. Sudden water pollution is the water pollution phenomenon that the river water quality deterioration rate accelerates in a short time due to the human’s behavior, it owns the characteristics of large water quality change and restoration rate, easy to form a water pollution accident and hard to take defensive measures in time. In this paper, we research the ammonia nitrogen pollution accidents of a river through data collection, actuality monitoring, data analysis and the application of water quality prediction model, explore the varying patterns of pollutants in river after taking artificial compulsory measures, propose the suitable emergency countermeasures for sudden water pollution accidents. It has great reference significance and practical value for future treatment and controlling of sudden water pollution accidents.The final results shows that, the pollutants can be well controlled by the artificial mandatory emergency measures such as artificial rainfall, introducing the water from other rivers after the ammonia nitrogen accident, and the water quality can be restored to original level 10 days later. As the main pollutants, the decreasing concentration of ammonia nitrogen in a sudden accident can be attributed to the combination of dilution of river water and oxidation by dissolved oxygen, and the oxidation is more apparent than former. With the excessive consumption of dissolved oxygen, the ammonia nitrogen will be oxidated to nitrite nitrogen and nitrate nitrogen; the concentration of dissolved oxygen picks up after the concentration of ammonia nitrogen decreasing significantly. Velocity is the most important factor which influences the diffusion of pollutants in river. Pollutants diffusion velocity and decay rate are both positive correlation with the river velocity. We can control the diffusion of pollutants by means of controlling the river velocity.This research simulating and calculating the river water quality using time series model, and the calculation results coincide well with the actual monitoring results. The concentration of ammonia nitrogen decreased to under 10 mg/L after 14 days and under 1 mg/L after 22 days. It can be seen that the measures of introducing water is economical and can achieve the good performance for controlling the pollutants.