Expanded reading: sewage treatment (sewage treatment,wastewater treatment): in order to make the sewage to achieve the drainage of a certain body of water or re-use of the water quality requirements of its purification process. Wastewater treatment is widely used in construction, agriculture, transportation, energy, petrochemicals, environmental protection, cityscape, medical, food and beverage and other fields, but also more and more into the daily life of ordinary people.