Development of controlling method of combined fouling for the diversification of water source and establishment of sustainable membrane treatment system

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K12228
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 64020:Environmental load reduction and remediation-related
• Research Institution: Niigata University of Pharmacy and Medical and Life Sciences
• Principal Investigator: Ohno Masaki 新潟薬科大学, 応用生命科学部, 助教 (40781216)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 逆浸透膜 / ファウリング制御 / ナノバブル / 次亜塩素酸ナトリウム / 持続可能な水処理技術

Outline of Final Research Achievements

In this research, the washing method that combined sodium hypochlorite (chlorine) and nanobubbles was developed to control complex membrane fouling caused by microbial biofilms and inorganic salt scale on reverse osmosis (RO) membrane treatment. It was shown that the combined washing with chlorine and nanobubbles could effectively control the complex fouling that formed as a biofilm with scale on the membrane surface. Especially, some examinations of the washing conditions showed that lowering the operating pressure during washing increased the washing effect of nanobubbles, and that a synergistic effect was achieved when chlorine and nanobubbles were used in combination. Furthermore, it was also clarified that by the application of this washing method, the complex fouling can be stably controlled for a long-term.

Free Research Field

環境工学

Academic Significance and Societal Importance of the Research Achievements

RO膜を利用した水資源の確保は世界的にも深刻な水不足の解決のために重要な技術である。本研究成果は塩素の殺菌作用とナノバブルの浮上・剥離作用の相乗効果による高効率膜面洗浄剤として利用することで、これまでの膜処理において対応が不十分であった複合ファウリングを制御し、より持続的な膜処理を可能にする。多様化していく水源に対して膜面堆積物の種類に応じた対処が必要であったが、本手法ではその種類を問わず剥離除去できるため、原水水質の複雑な水源におけるファウリング制御を考える場合に重要な技術となる。また、ナノバブル特有の極小微粒子を活かしたファウリング制御の知見は今後の水処理技術の発展にも大きな貢献である。