RO Applications in wastewater reclamation for re-use

Abstract In late 1975, a reverse osmosis plant with a capacity of 370 M3/16 hrs of day was put on stream to reclaim the plating wastewater which contains 1,000 – 1,500 ppm TDS after a primary wastewater treatment system of conventional oxidation-reduction process. The newly installed system of advanced water treatment consists of RO plant preceded by its pretreatment and ion exchange demineralizer to reclaim water by 90 per cent of inflowing wastewater for its re-use such as for boiler feed. A combination of optimized pretreatment was applied and its operation and maintenance were performed at the satisfactory conditions. And the RO plant has successfully been operating for more than 18 months with no need of replacing any membrane modules, the salt rejection and product water flux being maintained to date at the rated levels. Due to wastewater fluctuation in its quality, the operation and control of RO plant and its pretreatment may involve some difficulties that have not experienced in the desalting process of ground water or brackish well water, that means, much more difficult and different efforts are needed for wastewater reclamation, from the view points of RO technology. However well-selected pretreatment of RO feed is very helpful to eliminate such difficulties in RO application for water reclamation from wastewater. This paper discusses the performance and maintenance of RO application in wastewater reclamation for its re-use. Further information of another RO plant with a capacity of 2,700 M3/D installed for reclamation on wastewater from etching process, together with the information of 200 M3/D RO plant installed to treat the lab waste for its re-use, is also provided here.