Yudean Shajiao C Power Plant currently has an installed capacity of 3×660MW units, supporting an open-pit coal yard, with an area of approximately 16,000 square meters. The coal-containing wastewater mainly comes from coal-containing wastewater collected at various transfer stations, coal terminals, open-pit coal yards and other sites in the coal transportation system. It is located at the estuary of the Pearl River in Guangdong Province, with abundant rainfall and high environmental pressure. The original design was a multi-stage sedimentation + flotation tank system with a processing capacity of 280t/h. The system covers an area of more than 6,000 square meters and is shared with boiler wastewater. During the rainy season, the flow of coal-containing wastewater exceeds 300m³/h, which has exceeded the processing capacity of the original system, and the effluent from the original system cannot meet the first-level discharge standard in the "Integrated Wastewater Discharge Standard" (GB8978-1996). In response to the situation of coal-containing wastewater, it is urgent to seek fast, low-cost, automated, and up to standard treatment methods. The HDCY integrated multi-effect clarification system independently developed by Beijing Huade Ventures has completely solved the shortcomings of difficult treatment of coal-containing wastewater, fouling of the system, large floor space, and high cost. The system consists of modules such as a coagulation reaction tank, a flocculation reaction tank, a pre-sedimentation area, an inclined tube separation area and a medium recovery area, and covers an area of only 60 square meters. The HDCY integrated multi-effect clarification system highly integrates various technologies that are conducive to solid-liquid separation, such as chemical coagulation, mechanical stirring, loading sedimentation, and inclined tube separation. With the help of reasonable media action and sludge return measures, it maintains the loading efficiency. The sedimentation tank has the advantages of high speed, compactness, good effluent quality, strong impact resistance, and saving operating costs. It also increases the flexibility of operation. Suspended solids, heavy metals and other substances in the water settle in the form of flocs, thereby achieving qualified water discharge effect.
For the treatment of coal-containing wastewater in this plant, the HDCY integrated multi-effect clarification system is designed to treat 7500m3/d. Practice has shown that the suspended solids in the system effluent are less than 10ppm and the turbidity is less than 1NTU. All indicators are fully consistent with the reuse of coal-containing wastewater. standard, and the processing cost of the entire system is only 0.019usd/ton.