What is the Level A standard for wastewater discharge?
2 Answers
The Level A standard for wastewater discharge mainly includes the following four items: 1. Chemical Oxygen Demand (COD) 50 60 100 120. 2. Biochemical Oxygen Demand (BOD5) 10 20 30 60. 3. Suspended Solids (SS) 10 20 30 50. 4. Petroleum 1 3 5 15. The following removal rate indicators apply under specific conditions: When the influent COD is greater than 350mg/L, the removal rate should be greater than 60%; when the BOD is greater than 160mg/L, the removal rate should be greater than 50%.
I'm quite familiar with automotive exhaust, but the Class 1A emission standard you mentioned actually belongs to the wastewater treatment field. In the 'Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants', Class 1A represents the most stringent emission limits: COD must not exceed 50mg/L, ammonia nitrogen must be controlled below 5mg/L, and total phosphorus is limited to 0.5mg/L. This standard is nearly equivalent to the Surface Water Class III standard and is primarily applied in sensitive water areas like drinking water source protection zones. While it's not directly related to vehicles, car wash facilities could reference this standard for wastewater treatment, especially since environmental regulations are becoming stricter - some cities now require car wash water to meet at least Class 1B standards before discharge.
