Abstract

The hot-dip galvanizing consumes raw materials, supplies, and influence in the quantity/quality of wastewater, opening advantage for its segregation, reuse, and recycling. Therefore, the aim was to establish strategies for segregation, recycling, and preventives process of wastewater from a hot dip galvanizing enterprise (>10,000 t/year of galvanizing steel or gs). A mass balance (inputs-outputs by 1 t gs), Sindex considering organic and inorganic parameters for segregation/recycling, and Water Pinch (Zn, COD, TDS) for reuse opportunities were determined. Flows diagrams were based on three scenarios that combine segregation/reuse/recycling, comparing saving water, energy, costs, and carbon dioxide equivalent (CO2-eq) emissions. Results (mass balance) demonstrated that the water consumption in the rising phases (2,355.2 Lit gs) corresponding to 95% of the total water demand. The best scenario combined reuse/segregation/recycling, which decreased up to 36% of treated wastewater, up to 40% of chemicals consumption, about 41% of treatment cost, close to 38% of energy consumed, up to 17% of CO2-eq emissions by wastewater treatment. Therefore, taking preventive measures without the need of technological changes (treatment) can achieve on efficient water management within of the hot dip galvanizing production in developing countries.