Abstract
Water reuse is becoming a critical technology for industrial plants to remain competitive as environmental regulations become more stringent and as municipal water demands increase. The basic challenge of water reuse is to meet the water quality requirements of both the plant effluent and the in-plant processes in an economical fashion. The complex nature of water reuse problems demands a systematic approach for achieving solutions. Such an approach has been developed which integrates the plant audit, numerical process simulation, and pilot-scale experiments to optimize reuse system designs in the sense of both technical and economic merits. Two case studies are presented which illustrate some of the capabilities of this highly flexible approach to water reuse. The case of an oil refinery demonstrates the utility of process modelling prior to pilot-level testing, which is then used to determine system operating parameters and costs. The role of numerical process simulation in predicting process water chemistry and overall economics is emphasized in the case of a copper smelting plant.