Silicon Removal in Photovoltaic Wastewater Reuse System

According to the process flow of the photovoltaic industry, the sources of photovoltaic wastewater are: 1. Polycrystalline silicon wastewater 2. Organic silicon wastewater 3. Silicon wafer cleaning wastewater 4. Grinding and polishing wastewater 5. Mortar recycling wastewater; The main pollutants in photovoltaic wastewater are polyethylene glycol organic matter COD, silicates, ultrafine silicon powder silicon carbide suspension, fluoride ions, ammonia nitrogen, high concentration acid wastewater, etc.

With the trend of reducing and reusing industrial wastewater, many photovoltaic companies adopt membrane method for wastewater reuse based on the different composition and content of workshop discharge water. For pre cleaning wastewater, workpiece cleaning wastewater, corrosion workshop cleaning pure water, and wastewater treatment station discharge water, RO reverse osmosis technology is also widely used due to its advantages of low energy consumption and easy operation.

However, during the operation of the RO system, due to concentration polarization, silicates, ultrafine silicon powder, and suspended silicon carbide in photovoltaic wastewater accumulate significantly on the membrane surface, usually reaching saturation and depositing on the membrane surface, forming silicon scale.

Compared to other types of inorganic scale, the control measures for silicon scale in RO systems are more complex because silicon scale has strong adhesion to the membrane surface. Some commonly used membrane cleaning agents often cause irreversible degradation of membrane materials, leading to a significant reduction in the service life of RO membranes. Therefore, when treating this type of wastewater, it is recommended to consider using desilication resin for pre-treatment of the incoming water.

HP4800, a highly selective silicon removal resin from Haipu, is a porous polymer that utilizes the Donna membrane effect to pre enrich silicon ions on the surface groups of the polymer material, and then selectively remove silicon through special silicon removal groups inside the polymer. Therefore, HP4800 has high adsorption selectivity and high adsorption accuracy.