Manifestations of harm from coking wastewater

　　The following is an introduction to the manifestations of the hazards of coking wastewater:

　　1. Reduce the ornamental value of water bodies

　　If coking wastewater is discharged into water bodies with ornamental value, the ornamental value of the water body will be greatly reduced. Usually, 4.6 mg of dissolved oxygen is consumed to oxidize 1 mg of ammonia nitrogen into nitrate nitrogen. The more ammonia nitrogen there is in the water body, the more dissolved oxygen is consumed, and the more serious the black and smelly phenomenon of the water body becomes, which affects the survival of aquatic organisms such as fish in the water body, making them prone to death due to lack of oxygen. Eutrophic water quality is not only black and smelly, but also has poor transparency (only 0.2m), which often affects the ornamental and tourism value of rivers, lakes and lakes. With the improvement of people's living standards, tourism has become an increasingly widespread demand. Rivers, lakes and parks with good water quality are important parts of urban landscapes, and are also the best places for people to live, entertain, swim, watch and relax. However, if the lake is eutrophic, the lake water is black and smelly, people cannot swim or tour in it, and they can't watch the fish playing in it, which greatly reduces the entertainment and ornamental value of these lakes. It affects the lives of local people and seriously affects the development of local tourism, causing great economic losses.

　　2. Harm to agriculture

　　Using untreated coking wastewater to irrigate farmland directly will reduce crop yields and cause crop death, especially during the sowing period and seedling development period. The seedlings are weak in resistance and the phenol-containing wastewater poisons them. If the wastewater that does not meet the discharge standards is used for irrigation, the harvested grains and fruits and vegetables will have a peculiar smell; the oil substances in the coking wastewater can block the pores of the soil, and the high salt content can cause the soil to become salinized; if the TN content in the agricultural irrigation water exceeds 1mg/L, the crops will absorb excess nitrogen and cause lodging.