Project Overview
- A photovoltaic enterprise in Jianhu County, Jiangsu, established in 2023 in the Jianhu High-Tech Zone, specializes in the slicing, cleaning, and sorting of photovoltaic silicon wafers. With a total investment of approximately RMB 1 billion, the facility is equipped with over 250 units of machinery including slicers and degumming cleaning lines, and is designed to achieve an annual production capacity of 5 GW of high-efficiency monocrystalline silicon wafers upon full operation.
- The project is designed with a wastewater treatment capacity of 2,000 m³/d, with equipment installation and commissioning now completed.
- The wastewater primarily originates from large-cycle filter press effluent, cleaning agents, workshop replacement fluid and insert sheet operations, cleaning water, as well as RO brine, cooling tower drainage, and scrubber discharge. The main pollutants in the wastewater are pH, COD, and SS.
Key Technical Challenges
The slicing wastewater, degumming wastewater, insert sheet wastewater, and cleaning overflow wastewater all contain high levels of COD and SS. For these wastewater streams, priority must be given to SS removal to subsequently achieve COD compliance.
Process Flow
- Slicing wastewater: Slicing wastewater → 1# Coagulation & Sedimentation Tank → Hydrolysis Acidification Feed Tank
- Degumming wastewater, insert sheet wastewater, and cleaning wastewater: Three wastewater streams → 2# Coagulation & Sedimentation Tank → DAF System → Hydrolysis Acidification Feed Tank
- Other low-concentration wastewater: Domestic sewage → Hydrolysis Acidification Feed Tank
- Combined wastewater: Hydrolysis Acidification Feed Tank → Hydrolysis Acidification Tank → Facultative Tank → Aerobic Tank → Secondary Sedimentation Tank → DAF System → pH Reclamation Tank → Standardized Discharge Outlet → Industrial Park WWTP
