To contextualize coking plant wastewater, it is first necessary to clarify the core function of coking plants. These facilities utilize coal of varying grades as raw materials, which are proportionally blended, uniformly crushed, compacted, and subjected to high-temperature dry distillation in carbonization chambers. This process yields coke with high abrasion resistance and shatter strength, primarily for blast furnace ironmaking.
Wastewater is inevitably generated during these production operations—how should such wastewater be managed, and can it be discharged directly?
Direct discharge is strictly prohibited. The wastewater must first undergo disinfection treatment, followed by comprehensive testing of water quality indicators using water quality analyzers. Compliance with regulatory standards is verified based on test data, and only after confirmation of meeting requirements can discharge proceed. Specific monitoring indicators are analyzed at distinct monitoring points, as outlined below:
1.Total Wastewater Discharge Outlet: Mandatory installation of online water quality monitoring equipment is required, with different instruments employed for testing distinct parameters. Key monitored parameters include total phosphorus (TP), total nitrogen (TN), ammonia nitrogen (NH₃-N), petroleum hydrocarbons, volatile phenols, chemical oxygen demand (COD), suspended solids (SS), and cyanide.
2.Wastewater from Individual Workshops or Production Facilities: The monitored parameters differ slightly here, focusing on flow rate and polycyclic aromatic hydrocarbons (PAHs).
3.Recovery Pools and Water Replenishment Outlets: Water quality monitoring is also required for pools used for coking coal washing, blast furnace flushing, and their associated water replenishment outlets. Core indicators include volatile phenols, pH, NH₃-N, and COD.
4.Rainwater Discharge Outlet: This must be isolated from other discharge outlets. Testing is conducted 15 minutes post-rainfall, with key parameters including COD, NH₃-N, and petroleum hydrocarbons.
5.Domestic Sewage Discharged Directly into the External Environment: Corresponding water quality monitoring is mandated, covering indicators such as NH₃-N, TP, TN, and animal/vegetable oils.
In summary, comprehensive monitoring at all wastewater discharge points is essential to ensure that water quality indicators meet standards prior to discharge or recycling.
