Sewage treatment (wastewater treatment): The process of purifying sewage to meet the water quality requirements for discharging into a certain water body or for reuse. Sewage treatment is widely applied in various fields such as construction, agriculture, transportation, energy, petrochemicals, environmental protection, urban landscaping, healthcare, and catering, and it is increasingly becoming a part of ordinary people’s daily lives.

The topic of water pollution, especially groundwater pollution, has been constantly raised. In places like Hangzhou and Wenzhou in Zhejiang, farmers or entrepreneurs have offered to pay for the environmental protection bureau directors to swim in the river, in order to draw attention to the severity of water pollution. Although all environmental protection bureau directors chose to remain silent or refused the offer, the awakening of public awareness of environmental protection and the concern for water pollution have reached an unprecedented level.

Surface water pollution is evident, yet groundwater pollution is even more shocking. Out of China’s 1.3 billion population, 70% rely on groundwater for drinking, and over 400 out of more than 660 cities use groundwater as their drinking water source. However, according to reports, 90% of urban groundwater across the country has been contaminated.

Another set of data also indicates that groundwater is facing severe challenges. In 2011, among the 857 monitoring wells evaluated in nine provinces and cities including Beijing and Shanghai, 2% were classified as Class I and Class II, while as many as 76.8% were classified as Class IV and Class V.

Among the nine provinces and cities, Hainan Province boasts the best water quality, predominantly Class II; Shanghai and Beijing come next, with mostly Class III; Heilongjiang and Jiangsu have the highest proportion of Class IV water, while Jilin, Liaoning, Guangdong, and Ningxia generally only reach the Class V level.

The situation of water pollution has been continuously worsening, drawing unprecedented attention to the wastewater treatment and regeneration industry. In the past two years, the gross profit margin in various regions has remained at around 70%, and even exceeded 100% in some areas, indicating great potential for the industry’s development.