Kurita Water Industries. Ltd.. Japan En late 1975, a reverse osmosis plant vich a capacity of 370 74'116 hrs of day vas put on stream to reclaim the plating uastevater vhich coutaios 1.000 -1.500 ppn TLIS after 9 primary vastevater treatment system 0E conventional oxidation-reduct2,an process. The newly installed system of advanced vater treatment coasfsts of RO plant preceded by its pretreatment aad ion exchange demiueralizer to reclafm water by 90 per cent of iofloviug vastevater for its re-use such as for boiler feed. A comb*sation of optf.mfzed pretreatmeat vas applied and Lts operation and caintenauce vere performed at the satisfactory conditions. And the RO plant has successfully been operating for more than 18 ttonths with co need of replacing any membrane nodules, the salt rejection and product vater flux being ceintained to date at the rated levels. Due to vastevater fluctuation in its quality. the operation and control of RO plant and its pretreatment pay involve scme difficulties that have cot experienced in the desalting process of ground vater or brackish veil water. that ceans, much more difficult and different efforts are needed for vastevater recfaratiou, from the view points of RO technology. Rovever well-selected pretrcatueat of RO feed is very helpful to eU.vinate such difffcultfes in RO application for vater reclarration from vastevater. 'Chia paper discusses the performance and maintenance of RD application in vastevater reclamation for its re-use. Further infontation of another RO plant vith a capac'ty of 2,700 LI'/D installed for reclamatioa oo vaatevater frcn etching process. together uLth the information of 200 #'ID RO plant installed to treat the lab vaste for its re-use. is also provfded here. In the vastevater reclamation for re-use. a desalting process becomes necessary to prevent the accumulation of dtisolved sd.cs or to reduce the salt coatents in the line of vastevater f&v. Kurita Water Industries, Ltd. has schemed out and built sany reverse omaosia plants as desaltiug process since late 197i. the cmxbiced capacity reachiog more than SO.000 @/day in total.