Mitsubishi Heavy Industries Technical Review
    Vol. 53 No. 4 (2016)   New Products & Technologies
    Technical Papers

    Study of Environmentally-friendly Pretreatment Technology for SWRO Desalination Plant

    Yoshiaki Ito,
    Masayuki Tabata,
    Katsunori Matsui,
    Kazuhisa Takeuchi,
    Gaku Kondo,
    Hideo Iwahashi

    Various chemicals are used in the operation of SWRO desalination plants. The use of chemicals has significant environmental and economic influences, such as increased amounts of waste and plant operational costs. Therefore, a process in which the chemical consumption is reduced or no chemicals are used is highly desired. Mitsubishi Heavy Industries, Ltd. (MHI) has been working on the development of chemical-free pretreatment technology that is both environmentally-friendly and economically efficient. MHI conducted a demonstration experiment in Japan and Qatar, adopting the chemical-free sand filtration technology utilized in the Japanese salt manufacturing industry. As a result, the experiment verified that the operation of RO membranes is possible with stable desalination performance and SWRO differential pressure, proving the applicability of chemical-free sand filtration to SWRO desalination using RO membranes.