Polysilicon Plant Waste Water
Wastewater is generated Polysilicon plant from the Process Vent Hydrolyzers, TCS plant Quench, and in the Etch plant. The wastewater comprises mostly of Silicates and Salts (calcium and/or sodium), silicon fines and metal oxides and must be treated to meet the local requirements for pH, TSS (total suspended solids) and TDS (total dissolved solids). In some cases the wastewater can also contain unreacted chlorinated silanes and silicon gels which make the treatment more challenging.
Verantis has the experience and know how to treat this wastewater. TSS removal is accomplished by chemical and physical conditioning of the wastewater and subsequently separating out the solids in a filter press. TDS removal is accomplished by separating out the salts as an aqueous salt solution or as solids in a multi-effect evaporator and/or crystallizer. The water from this plant may be recycled back as clean process water making this a “Zero-Discharge” system.