Water pollution and its harm

Since the beginning of this century, with the rapid development of modern industry, a large number of discharge of all kinds of wastewater, the natural water system has been significantly polluted, the water quality has generally declined, and the fresh water available for safe use is increasingly insufficient。

As far as our country is concerned，According to the Announcement of China's Ecological and Environmental Statistics Annual Report 2020，More than 60 billion tons of wastewater were discharged nationwide，Chemical oxygen demand emissions of about 25 million tons，Ammonia nitrogen emissions are nearly 1 million tons，Total nitrogen emissions are more than 3 million tons，Oil emissions were more than 3,700 tons，The emission of volatile phenol is nearly 60 tons，The cyanide discharge is about 42 tons，Heavy metal emissions are about 73 tons。The water bodies in many areas of our country are polluted。Due to the pollution of natural water system, and in some areas increasingly serious, it together with air pollution, noise pollution and subsidence of strata and other public hazards, constitute one of the most serious social problems in the world today。

The following table lists the types and hazards of water pollution