Water mass balance to assess the demand for water and wastewater generated by trading groups in industrial zones

The development of Industrial Zones in Vietnam will put pressure on water resources at local as well as national scale, due to the large amounts of water consumed and discharged to environment. This study, via water mass balance, provides analyses and assessments on water demand and wastewater generated in each trading groups (industrial sectors) of the Long Thanh Industrial Zone and the Nhon Trach III Industrial Zone phase 2, Dong Nai – the province with the most industrial zones in Vietnam. According to the water mass balance calculation results, the water demand of industrial sectors depends on their manufacturing characteristics. Of which, Textile and Garment are the sectors with the highest demand, as well as highest water loss rate and highest amount of wateswater dischared. Meanwhile, Electronic and Construction Materials cosume the least amount of water. Machinery sector has the lowest amount of water loss. The wastewater/supply water ratio of the Long Thanh Industrial Zone is always 1,1 (for Textile) to 1,5 (for Machinery) times higher than the Nhon Trach III Industrial Zone phase 2, while the wastewater/supply water ratio of the Nhon Trach III Industrial Zone phase 2 is always less than 80%.