METHOD OF TREATING WASTE WATER CONTAINING ORGANIC SUBSTANCE AND TREATING APPARATUS

摘要

In the performing of treatment/recovery with the use of RO membrane separator as to waste water containing organic substances in high concentration or low concentration, discharged from electronic device manufacturing plants or other facilities of various fields, not only can stable treatment be conducted for a prolonged period of time while preventing biofouling and flux drop attributed to attachment of organic substances to the membrane surface in the RO membrane separator but also the TOC concentration in water can be efficiently reduced to thereby obtain treated water of high quality. Waste water containing organic substances is loaded with a scale inhibitor amounting to at least 5 times by weight the calcium ion concentration in the water and further loaded with an alkali so as to adjust the pH value to 9.5 or higher, and thereafter passed through RO membrane separator (2). By virtue of the adjustment of the pH value of water fed to the RO to 9.5 or higher, any biofouling of the RO membrane separator can be prevented and also any attachment of nonionic surfactant to membrane surface can be prevented to thereby avoid any flux drop. By virtue of the addition of the scale inhibitor, any membrane surface clogging by calcium carbonate scale under high pH conditions can be inhibited.