Yousei Katsu*, Toshihiro Tanaka* and Saburo Ito*

* EBARA Corporation

+ Correspondence should be addressed to Yousei Katsu:
(4-2-1 Honfujisawa, Fujisawa City Kanagawa 251 Japan)

Abstract

Research was carried out on an advanced treatment method using a microfiltration (MF) process as pretreatment and a reverse osmosis (RO) desalination process to simultaneously remove both organic pollutants and salinity from leachate. Treatment of the RO concentrate was done by an Electrodialysis (ED) and evaporation-drying process. A pilot plant using MF and RO was conducted for more than one year using raw water drawn from the coagulation/sedimentation process of the existing plant. A clarification performance test was first using the MF membrane process for pretreatment of the RO process. The pretreatment was extremely stable at a permeate flux of between 1.5 to 2.0 m/d, and an effective chemical washing of fouling membranes once every two months. The treatment of RO was also stable, and little permeate volume decrease was achieved with chemical washings once every one or two months. High quality effluent, desalination and removal of organic pollutants (COD and color) exceeded 98%, suggesting that the effluent was suitable for reuse. Results of applying a batch type ED process indicated that desalination and concentration could be done effectively.

Key words: microfiltration, reverse osmosis, electrodialysis, desalination, COD