Tire Industry Wastewater: Key Parameters to Monitor

Tire manufacturing generates wastewater from multiple stages, including compounding, extrusion, molding, and vulcanization, each contributing distinct pollutants. Consequently, discharge monitoring must cover both comprehensive indicators and process-specific parameters. 

China's current regulatory basis is the Emission Standard of Pollutants for Rubber Products Industry (GB 27632–2011), which sets limits for key pollutants from tire enterprises.

Routine testing at the discharge outlet typically includes pH, chemical oxygen demand (COD), five-day biochemical oxygen demand (BOD₅), suspended solids (SS), ammonia nitrogen, total nitrogen, total phosphorus, petroleum, and animal/vegetable oils. 

Among these, petroleum is a signature parameter for the tire industry, originating from lubricating oil leakage and oil-containing wastewater. Suspended solids consist mainly of carbon black particles, and their concentration directly reflects the loss of carbon black dust during production. COD and BOD₅ indicate the overall organic load, while nitrogen and phosphorus parameters track nutrient pollution.

Beyond these conventional indicators, some tire enterprises must also monitor sulfide, fluoride, and heavy metals. Sulfide derives from unreacted sulfur-containing additives in the vulcanization process, and its presence affects both process control and the stability of downstream biological treatment. Fluoride may be introduced through certain tire formulations. Heavy metals such as lead, cadmium, total mercury, and total arsenic are required under discharge permit management, even though tire production is not a major source—rubber additives and pigments can introduce trace amounts that still warrant monitoring.

In practice, key pollutant discharge units must conduct automatic monitoring of flow, pH, COD, and ammonia nitrogen at the main outlet, while other parameters are covered through periodic manual sampling. The logic behind this parameter framework follows a pollution chain: organic load, suspended particles, characteristic additives, and heavy metals. Only by understanding each parameter in the context of its production source can monitoring data effectively support process improvement and pollution control.