Simultaneous removal and concentration of arsenic from waste water by bipolar membrane electrodialysis

Research Project

Project/Area Number	18K04795
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Multi-year Fund
Section	一般
Review Section	Basic Section 26060:Metals production and resources production-related
Research Institution	Tohoku University
Principal Investigator	IIZUKA ATSUSHI 東北大学, 多元物質科学研究所, 准教授 (70451862)
Project Period (FY)	2018-04-01 – 2021-03-31
Project Status	Completed (Fiscal Year 2020)
Budget Amount *help	¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000) Fiscal Year 2020: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000) Fiscal Year 2019: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000) Fiscal Year 2018: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Keywords	ヒ素 / 排水処理 / 除去 / 高度濃縮 / 廃水処理
Outline of Final Research Achievements	Arsenic (As) removal from aquous solution and simaltenaous concentration using bipoler membrane electrodialysis (BPED) method has been conducted.Technical feasibility of the method has been confirmed with solution containing pentavalent arsenic (As(V)). Higher As conentration was achieved with higher volume ratio of solution in removal cells to that in concentration cells. Trivalent As (As(III)) in solution could be also removed and concetrated by the BPED method. Influences of coexisting ions and types of membrane have been also investigated. Lower limit for As removal in treated solution by the BPED method has been also examined.
Academic Significance and Societal Importance of the Research Achievements	廃水や環境水中に含まれるヒ素の効率的な処理の問題は世界的な共通課題となっており、より効率的な分離技術の開発が強く求められている。本研究では、複合膜であるバイポーラ膜を利用した水中のヒ素の除去と高度濃縮について着目し、研究を行った。バイポーラ膜を用いて電気透析を行うことにより予想通りに処理水からのヒ素の除去と濃縮水中でのヒ素の濃縮が起こることを確認した。また処理水と濃縮水の体積比、ヒ素の価数、水中の共存イオンやイオン交換膜の種類がヒ素の除去と濃縮に及ぼす影響についても検討した。