Volume reduction of acid waste water from Al-Mg alloy processing(anode oxidation)

A large amount of waste water containing HCl, H ₃PO ₄and HNO ₃is produced from Al-Mg alloy processing plant. The treatment cost is gradually increased each year, mainly due to the high neutralization cost. The original treatment process cannot meet discharge criteria of environmental protection. The Client finally adopted CSRE MD to reduce total volume of waste water to 1/80, and the MD brine is treated by Hazard waste treatment center, thereby saving treatment cost.   Project capacity is 86m³/d; feed TDS is 0.4~0.6%; MD brine TDS is 38~42%; concentration factor is 80 and only 1 ton of brine is treated by hazard waste treatment center. Simultaneously, 85 ton of water is recycled each day for freshwater saving. The MD system uses 85℃ circulating cooling water in the foundry workshop as heat source to provide heat source for CSRE membrane distillation equipment; electricity consumption is only 2.5kWh/m³.