Die-casting wastewater treatment

The die-casting industry generates highly contaminated wastewater with COD levels exceeding 20,000 mg/L – characterized by polysiloxanes, release agents, oils, and VOCs. In our case study, the authorities refused permission for discharge; external disposal would have cost €180/m³. An evaporator was ruled out due to VOC penetration and its large footprint. The solution was a compact forward osmosis (VO) system built on just three Euro pallets: quick to integrate, robust oil/VOC separation, and low emissions – all without the need for additional buildings. The result: clear, odorless effluent with COD levels below 50 mg/L and over 95% water reuse; only approximately 5% residual concentrate requires disposal. Economically, this means a jump from €180/m³ external to ~€52/m³ total costs (including residual disposal) – a saving of €128/m³ while simultaneously ensuring compliance.