The management of industrial wastewater discharge has achieved remarkable results

The overall volume of industrial water is still large

Industrial wastewater refers to the waste water, sewage and waste liquid produced in the industrial production process, which contains industrial production materials, intermediates and products lost with water and pollutants produced in the production process. The waste water produced by industrial water will cause irreversible harm to the surrounding environment and ecology if discharged at will.

In recent years, in order to reduce the discharge of industrial wastewater, China first reduces industrial water consumption from the source, 2015-2020, China's industrial water consumption and the proportion of total water consumption are decreasing year by year. In 2020, China's industrial water consumption will be about 119.1 billion cubic meters, accounting for 18.2%. In general, China's industrial water management effect is remarkable, but the overall volume of China's industrial water consumption is still large, and the industry is still facing a large demand for industrial wastewater treatment.

Wastewater treatment capacity has been strengthened

At present, China's industrial wastewater basically enters the urban sewage pipe after discharge, and is treated in the urban sewage treatment plant. From the statistics of the Ministry of Housing and Urban-Rural Development, from 2010 to 2019, the number of urban and county sewage treatment plants and the sewage treatment capacity formed by them have increased year by year. By the end of 2019, 2,471 and 1,669 sewage treatment plants had been built in cities and counties across the country, an increase of 150 and 71 year-on-year. According to preliminary estimates, there will be about 2,679 and 1,809 pollution treatment facilities in China's cities and counties in 2020.

With the continuous increase of the number of sewage treatment plants, the wastewater treatment capacity of China's sewage treatment plants is also constantly improving. From 2012 to 2020, the treatment capacity of China's urban and county sewage treatment plants is increasing year by year, and the treatment capacity of urban sewage treatment plants is strong. In 2019, the treatment capacity of China's urban sewage treatment plants was 179 million cubic meters/day, and the treatment capacity of county sewage treatment plants was 35.87 million cubic meters/day, with a total of 214.87 million cubic meters/day. In 2020, the total treatment capacity of urban and county sewage plants in China will reach about 23.4 million cubic meters/day. Overall, China's wastewater treatment capacity has been strengthened continuously.

The level of recycling and utilization of industrial wastewater has also been continuously improved

The recycling of waste water is a part of the development of emerging water resources at this stage, and the recycling of industrial wastewater is also one of the important ways to reduce the discharge of industrial wastewater in China. The typical process of industrial wastewater recycling is to take the discharge water of the regional industrial wastewater treatment facility as the water source, after treatment, the recycled water distribution system is supplied to the users in the area for use or for other purposes, industrial wastewater recycling is mainly used for industrial water use, or domestic secondary water use in the industrial area, such as flushing, floor cleaning, car washing and other non-human contact purposes.

With economic development and social progress, the state attaches great importance to water-saving work, and the recycling amount of industrial wastewater is also constantly increasing. From 2015 to 2019, the amount of industrial wastewater reuse in China's cities and counties increased year by year, and the amount of urban industrial wastewater reuse in 2019 was 2347.11 million cubic meters, and the county was 204.15 million cubic meters, a total of 255,125 cubic meters. According to preliminary estimates, the total amount of industrial wastewater reuse in China's cities and counties in 2020 will be about 2,756,682 million cubic meters.

The management of industrial wastewater discharge has achieved remarkable results

Under the continuous decline in China's industrial water consumption, the continuous increase in the number of industrial wastewater treatment capacity and enterprises, and the continuous improvement of the level of industrial wastewater recycling, from 2010 to 2020, China's treatment of industrial pollution has made great progress, and the discharge of industrial wastewater has generally shown a downward trend. In 2020, industrial wastewater discharge will further decrease to 17.72 billion cubic meters.

From the point of view of pollutant emissions, there has also been a significant improvement, according to the "2016-2019 National Ecological Environment Statistical Bulletin" issued by the Ministry of Ecology and Environment of China, from 2016 to 2019, the main pollutants in China's industrial wastewater are COD(chemical oxygen demand), ammonia nitrogen, total nitrogen, and the overall emissions show a downward trend. It shows that the capacity of industrial wastewater treatment in China has been strengthened, and the quality of industrial wastewater treatment has also been improved. Specifically, COD has always been the largest pollutant category of industrial source wastewater discharge, which was 772,000 tons in 2019. Chemical oxygen demand represents the oxygen required by potassium dichrodate to oxidize organic matter in a liter of sewage under strongly acidic conditions, which can roughly represent the amount of organic matter in sewage. This was followed by total nitrogen, with 134,000 tonnes emitted in 2019. It can be seen that China's industrial wastewater discharge management has achieved remarkable results.