Wastewater reuse requirements and water quality standards for various industries

The Water Quality of Industrial Water for Urban Wastewater Recycling (GB T19923-2005) was merged with four other national standards for urban sewage recycling to form the "National Standards for Urban Sewage Recycling", which was awarded the second prize of the first China Standard Innovation Contribution Award by the Standardization Administration of China. The implementation of this standard makes the quality of urban sewage, reclaimed water and industrial water quality in China have standards to follow.

According to reports, the amount of urban sewage reclaimed water used in industry accounts for about 40% of the total number of urban sewage reclaimed water. The standard of "Industrial Water Quality for Urban Sewage Recycling" is mainly applicable to cooling water, washing water, boiler water, process water, product water, etc. For the first time in the country, this standard clarifies 20 important control project indicators for the utilization of urban sewage reclaimed water as industrial water.

There is also a design code for sewage recycling engineering (GB 50335-2002), I don't know if it is still useful.

The current situation is that reclaimed water is only used more in some industries, and if the country has standards, it means that these industries use reclaimed water, or encourage these industries to use it, but not all industries have relevant standards.

Water reuse standards Industrial water quality.

There are Chinese sewage treatment projects on the Internet, you can find them.

Legal analysis: According to the pollutant discharge standards of urban sewage treatment plants: standard A of the first-class standard and standard B of the first-class standard, its applicable conditions and environmental requirements are as follows:

1. The A standard of the first-level standard is the basic requirement for the effluent of the urban sewage treatment plant to be used as reuse water. When the effluent of the sewage treatment plant is introduced into rivers and lakes with small dilution capacity for urban landscape water and general reuse water, the A standard of the first-class standard shall be implemented, and the effluent of the urban sewage treatment plant shall be discharged into the GB3838 surface water functional waters (except for the specified drinking water source protection areas and swimming areas) GB3097 seawater second-class functional waters and closed or semi-enclosed waters such as lakes and reservoirs, and the B standard of the first-class standard shall be implemented.

Legal basis: Law of the People's Republic of China on the Prevention and Control of Water Pollution

Article 4: The people at or above the county level shall include water environmental protection efforts in the national economic and social development plans. Local people at all levels are responsible for the quality of the water environment in their respective administrative areas, and shall take timely measures to prevent and control water pollution.

Article 5: Provinces, cities, counties, and townships are to establish a system of river chiefs, and organize and lead efforts such as the protection of water resources, the management of water shorelines, the prevention and control of water pollution, and the governance of the water environment in rivers and lakes within their respective administrative regions.

Article 6: The State implements a responsibility system and an evaluation and evaluation system for water environmental protection goals, and makes the completion of water environmental protection goals the content of the evaluation and evaluation of local people** and their responsible persons.

Legal analysis: Reclaimed water refers to non-potable water that can be reused within a certain range after all kinds of wastewater are treated to meet the specified water quality standards. Reclaimed water sources are divided into high-quality miscellaneous drainage and domestic sewage in accordance with the Code for Design of Reclaimed Water in Buildings (GB50336-2018) and the Code for Design of Urban Sewage Recycling Engineering (GB50335-2016).

1) Drainage of toilets, bathtubs and showers in public baths, etc.

2) Washing and drainage;

3) Drainage of air conditioning circulating cooling water system;

4) condensate;

5) Swimming pool sewage;

6) Laundry drainage;

7) kitchen drainage;

8) Flush and drain the toilet.

Reclaimed water sources are generally not a single water source, and most of them have three combinations:

1) Toilet drainage, shower drainage, and circulating cooling water are called high-quality miscellaneous drainage, which should be preferred;

2) Domestic drainage other than toilet flushing drainage is called miscellaneous drainage;

3) Domestic sewage, that is, the general term for all domestic drainage, this water quality is the worst.

The water quality of reclaimed water used for toilet flushing, road cleaning, fire protection, urban greening, vehicle washing, building construction and other miscellaneous uses shall be implemented in accordance with the urban miscellaneous water standards in the "Urban Sewage Recycling and Urban Miscellaneous Water Quality" (GB T18920-2002).

Reclaimed water is used for landscape environmental water, and its water quality should comply with the provisions of the national standard "Urban Sewage Recycling and Landscape Environmental Water Quality" (GB T18921-2002).

Legal basis: Article 2 of the Standardization Law of the People's Republic of China The standards (including standard samples) mentioned in this law refer to the technical requirements that need to be unified in the fields of agriculture, industry, service industry and social undertakings.

Standards include national standards, industry standards, local standards, group standards, and enterprise standards. National standards are divided into mandatory standards and recommended standards, and industry standards and local standards are recommended standards.

Mandatory standards must be enforced. The State encourages the adoption of recommended standards.

Due to the wide range of industrial production, the requirements for water quality vary greatly among different industrial categories. When considering the water quality labeling of industrial reuse water, we should proceed from the actual situation and determine the corresponding water quality standards for industrial reuse based on the water quality requirements of various types of industrial water

1. In the process of heat exchange, the beam is skillful, and no scaling is generated.

2. It does not corrode the cooling system.

3. Nassamine does not produce much foam.

4. There is no excess nutrients that help the growth of microorganisms.

Summary: For other types of industrial water, such as raw material water, process water, and boiler water, there is no corresponding water quality standard for reuse water. If the reclaimed water is to be used for various types of industrial branches, the water quality must meet the water quality standards for the relevant industry applications.

The water quality standard of urban miscellaneous water for urban sewage recycling is: the concentration of ammonia nitrogen in raw water is 75 115 mg l, and the concentration of ammonia nitrogen in effluent is less than 5 mg l. The quality of urban miscellaneous water is suitable for toilet flushing, vehicle washing, urban greening, road cleaning, fire protection, building construction and other miscellaneous reclaimed water.

Article 9 of the Regulations on Urban Drainage and Sewage Treatment.

The competent department of urban drainage shall organize the implementation of the urban drainage and sewage treatment plan prepared by the people at the same level for approval, and report to the competent department of urban drainage at the next higher level for the record. Once the urban drainage and sewage treatment plan is approved and published, it shall be strictly implemented; Where it is truly necessary to revise due to economic and social development, it shall be submitted for examination and approval in accordance with the original approval procedures.

Article 10. Local people at or above the county level shall, in accordance with the requirements of urban drainage and sewage treatment planning, increase investment in the construction and maintenance of urban drainage and sewage treatment facilities.

Article 11. The land for the construction of urban drainage and sewage treatment facilities determined by urban and rural planning and urban drainage and sewage treatment planning shall not be changed without authorization.