An approach to industrial water conservation – A case study involving two large manufacturing companies based in Australia

This study presents the application of an integrated water management strategy at two large Australian manufacturing companies that are contrasting in terms of their respective products. The integrated strategy, consisting of water audit, pinch analysis and membrane process application, was deployed in series to systematically identify water conservation opportunities. Initially, a water audit was deployed to completely characterize all water streams found at each production site. This led to the development of a water balance diagram which, together with water test results, served as a basis for subsequent enquiry. After the water audit, commercially available water pinch software was utilized to identify possible water reuse opportunities, some of which were subsequently implemented on site. Finally, utilizing a laboratory-scale test rig, membrane processes such as UF, NF and RO were evaluated for their suitability to treat the various wastewater streams. The membranes tested generally showed good contaminant rejection rates, slow flux decline rates, low energy usage and were well suited for treatment of specific wastewater streams. The synergy between the various components of this strategy has the potential to reduce substantial amounts of Citywater consumption and wastewater discharge across a diverse range of large manufacturing companies.

► The integrated water management strategy deployed in series can significantly reduce freshwater consumption.
► Water auditing and water pinch analysis are effective in identifying direct water reuse.
► The bulk of water savings will come from water treatment of the highly contaminated streams.
► Low-pressure membranes tested were suitable for reclamation of the highly contaminated streams.
► The membranes tested generally showed slow flux decline rates and low energy usage.