Effective treatment of uranium-contaminated soil-washing effluent using precipitation/flocculation process for water reuse and solid waste disposal. (August 2022)

• Record Type: Journal Article
• Authors: Lee, Hyun-Kyu; Chang, Seeun; Park, Wooshin; Kim, Tack-Jin; Park, Sungbin; Jeon, Hongrae
• Is Part Of: Journal of water process engineering. Volume 48(2022)
• Publication Date: 2022-08
• Subjects: Uranium -- Soil washing -- Precipitation -- Flocculation -- Radioactive waste disposal; Water-supply engineering -- Periodicals; Saline water conversion -- Periodicals; Seawater -- Distillation -- Periodicals; Sanitary engineering -- Periodicals; Sewage -- Purification -- Periodicals; 627
• DOI: 10.1016/j.jwpe.2022.102890
• Languages: English
• ISSNs: 2214-7144

Abstract

Abstract: The purpose of this study was to effectively purify uranium (U(VI))-contaminated soil-washing effluent using a precipitation/flocculation process, reuse the purified water, and dispose of the solid waste. The U(VI) ions in the effluent were easily removed as sediments by neutralization, and the metal sediments and suspended soils were flocculated–precipitated by polyacrylamide (PAM). The precipitate generated through the precipitation/flocculation process was completely separated into solid–liquid phases by membrane filtration (pore size <45 μm), and Ca 2+ and Mg 2+ ions remaining in the effluent were removed by distillation. Even if neutralized or distilled effluent was reused for soil washing, soil decontamination performance was maintained. PAM, an organic component of the filter cake, was successfully removed by thermal decomposition without loss of metal deposits including U(VI). Therefore, the treatment method of U(VI)-contaminated soil-washing effluent using the precipitation/flocculation process presented in this study can be used to effectively treat the washing waste of U(VI)-contaminated soil and dispose of the generated solids. Highlights: The U(VI) ions in the effluent were easily removed as sediments by neutralization. The metal sediments and suspended soils were flocculated-precipitated by polyacrylamide (PAM). The precipitate was completely separated into solid-liquid phases by membrane filtration. Even if neutralized or distilled effluent was reused for soil washing, soil decontamination performance was maintained. PAM, an organic component of the filter cake, was successfully removed by thermal decomposition.