China releases national standard for water reuse 
On December 31, 2021, the State Administration for Market Regulation and the Standardization Administration of the P.R.C (SAC) jointly released the “Water reuse guidelines-water quality management for water reclamation plants” (GB/T 41018-2021). The standard stipulates the reclaimed water grade classification for the urban recycling water, and is applicable for urban sewage distribution plan, safety management, performance evaluation, reclaimed water analysis and grading, and will come into force on July 1, 2022. Reclaimed water is classified into 3 grades A, B and C, and is further classified into 10 grades based on basic requirements for reclaimed water quality.
Indexes of grade classification
The indexes for reclaimed water grade classification are stipulated as follows.
|
Grade |
Basic requirements for water quality |
Typical application |
Treatment process |
|
| C | C2 | GB 5084 (Dryland crops, wet-seeded crops) | Farmland irrigation (dryland crops) and etc. | Secondary treatment and disinfection. The common secondary treatment including activated sludge process, biofilm process and etc. |
| C1 | GB 20922 (Fiber crops, dryland crops, oil-bearing crops, wet-seeded crops) | Farmland irrigation (wet-seeded crops) and etc. | ||
| B | B5 | GB 5084 (Vegetables) GB 20922 (Field vegetables) |
Farmland irrigation (vegetables) and etc. | Based on secondary treatment, third treatment and disinfection are adopted. According to the demand, third treatment can adopt one or multiple techniques from the following: coagulation, filter, biofilter, artificial wetland, microfiltration, ultrafiltration, ozone and etc. |
| B4 | GB/T 25499 | Green land irrigation and etc. | ||
| B3 | GB/T 19923 | Industrial usage (cooling water) and etc. | ||
| B2 | GB/T 18921 | Landscape usage | ||
| B1 | GB/T 18920 | Urban miscellaneous usage | ||
| A | A3 | GB/T 1576 | Industrial usage (boiler make-up water) | Based on third treatment, adopting advanced treatment and disinfection. Advanced treatment and third treatment can be jointly adopted. According to the demand, advanced treatment can adopt one or multiple techniques from the following: nanofiltration, reverse osmosis, advanced oxidation, biological activated carbon, ion exchange and etc. |
| A2 | GB/T 19772 (recharge by surface water) | Groundwater recharge (recharge by surface water) and etc. | ||
| A1 | GB/T 19772 (recharge by well water) | Groundwater recharge (recharge by well water) and etc. | ||
| GB/T 11446.1 | Industrial usage (electronic grade water) | |||
| GB/T 12145 | Industrial usage (thermal power plant boiler make-up water) | |||
For the outline of the above standard, please refer to the following URL (in simplified Chinese).
http://std.samr.gov.cn/gb/search/gbDetailed?id=D4BEFFF4EAD8B241E05397BE0A0AF581
