Sewage treatment? (sewage treatment, wastewater treatment): the process of purifying sewage to meet the water quality requirements for discharge into a certain water body or reuse. Sewage treatment is widely used in construction, agriculture, transportation, energy, petrochemical, environmental protection, urban landscape, medical treatment, catering and other fields, and it has also entered the daily life of ordinary people more and more.

The topic of water pollution is constantly being raised, especially groundwater pollution. In Hangzhou, Zhejiang, Wenzhou and other places, farmers or entrepreneurs invited environmental protection directors to swim in the river to arouse people's attention to the seriousness of water pollution. Although all environmental protection directors have chosen silence or refusal, people's awareness of environmental protection has awakened and their concern for water pollution has reached an unprecedented level.

Surface water pollution is obvious, and groundwater pollution is shocking. 70% of China's 654.38+03 billion people drink groundwater, and more than 400 cities in more than 660 cities use groundwater as their drinking water source. However, it is reported that 90% of urban groundwater in China has been polluted.