Composite electrochemical brackish water desalination system combining electrodialysis and capacitive deionization process

• Main Authors: JIN CHAE HYUN, KWON TAE OK, ROH HYUN CHEUL
• Format: Patent
• Language: English; Korean
• Published: 12.05.2021
• Subjects: CHEMISTRY; METALLURGY; TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE

The present invention relates to a composite electrochemical brackish water desalination system combining electrodialysis and a capacitive deionization process. According to the electric desalination technique of the present invention, an electrodialysis membrane method is used in the front stage to primarily reduce the concentration of high-concentration inflow TDS and the salt-reduced water is applied as inflow water for the capacitive electrosorption method in the back stage. By the multistage composite process, treatment is possible to the freshwater quality level of 500 mg/L or less in TDS concentration of the final treated water in an economical and efficient manner. The present invention includes: a raw water storage tank; an ED treatment unit where the raw water flows in by batch circulation from the raw water tank, the salt concentration of the raw water in the tank is primarily reduced by electrodialysis, and concentrated water undergoing desalination from the raw water is separated and discharged; and a CDI treatment unit where the salt-reduced water of the tank primarily salt-reduced in salt concentration by the ED treatment unit flows in, the residual ions from the inflow water are adsorbed and desorbed to a preset final target water quality by capacitive electro-adsorption, and the treated water is discharged to the outside. 본 발명은 전기 탈염 기술로서 전단에 전기투석막법을 이용하여 고농도 유입 TDS 농도를 1차로 저감시킨 탈염수를 후단에 축전식 전기흡착법의 유입수로 적용한 다단 복합공정을 구축하여 경제적이면서 효율적으로 최종 처리수의 TDS 농도 500 mg/L 이하의 담수 수질 수준까지 처리할 수 있도록 한 전기투석과 축전식전기흡착 탈염공정이 결합된 복합 전기화학적 기수담수화 시스템에 관한 것으로, 상세하게는 원수가 저장되는 원수탱크; 상기 원수탱크와 회분식 순환으로 원수가 유입되고 전기투석(Electro Dialysis) 방식을 통해 상기 원수탱크에 저장된 원수의 염 농도를 1차 탈염시키면서 원수로부터 탈염 처리되는 농축수를 분리 배출하는 ED처리부; 및 상기 ED처리부에 의해 염 농도가 1차 탈염 처리된 원수탱크의 탈염수가 유입되며 축전식 전기흡착 방식을 통해 유입된 탈염수로부터 잔존 이온을 기설정된 최종 목표수질까지 흡/탈착하고 그 처리수를 외부로 배출하는 CDI처리부;를 포함하는 것이 특징이다.