How to recycle wastewater treatment?

Industrial wastewater has the characteristics of complex types, strong pollution, difficult treatment, and great harm, and has always been a headache for the environmental protection department, which mainly comes from the paper industry, coal mining, iron and steel industry and petrochemical industry. In 2019, the total discharge of industrial wastewater in China is about 25.2 billion tons, and its reuse rate is not too high. Industrial wastewater has the characteristics of complex types, strong pollution, difficult treatment, and great harm, which has always been a headache for the environmental protection department, and this wastewater mainly comes from the paper industry, coal mining, steel industry and petrochemical industry. In 2019, the total discharge of industrial wastewater in China was about 25.2 billion tons, and its reuse rate was not too high, basically meeting the standard discharge. Basically, they all meet the standard emissions.

On January 11, 2021, ten ministries and commissions including the National Development and Reform Commission, the Ministry of Ecology and Environment, the Ministry of Science and Technology, and the Ministry of Industry and Information Technology jointly issued the Guiding Opinions on Promoting the Utilization of Sewage Resources (referred to as the "Opinions"), which proposed to encourage conditional industrial parks to coordinate the comprehensive treatment and resource utilization of wastewater, and establish point-to-point water use systems between enterprises. To realize the recycling and graded reuse of industrial wastewater, focusing on high-water consumption industries such as thermal power, petrochemical, iron and steel, nonferrous metals, paper making, printing and dyeing, organize the utilization of wastewater within enterprises, create a number of industrial wastewater recycling demonstration enterprises and parks, and promote the improvement of water efficiency of enterprises through typical demonstrations.

Basic principles of sewage resource utilization

Sewage resource utilization includes renewable water utilization, resource recycling and energy conversion and utilization, which needs overall research, overall planning and coordinated promotion. The utilization of recycled water should adhere to the basic principles of "water saving priority, overall promotion" and "according to local conditions, classified policies".

Sewage outlet

The effluent can be discharged into water bodies and reused after treatment.

Discharging sewage into a body of water is a traditional way out, it is natural to take water from a river and then discharge it back into the river, but before doing so, it is necessary to ensure that this action does not destroy the original function of the water body. Because the sewage needs to go through the purification process of gradual dilution and degradation, the sewage discharge is usually set downstream of the intake, so as not to adversely affect the water quality of the intake.

The shortage of water resources is a global problem, with the progress of science and technology, the continuous increase of water purification technology, the reuse of urban sewage is also increasing, so it is necessary to actively use urban sewage as fresh water resources, but need to be extra careful to avoid pollution.

Sewage reuse should meet the following requirements:

Should not have adverse effects on human health; Should not have adverse effects on environmental quality and ecosystems; It should not adversely affect product quality; It should meet the water quality requirements or standards of the application object; Should be acceptable to users and the public; There should be a guarantee of safe use; The reuse system is technically feasible and easy to operate.