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DOI : 10.17640/KSWST.2022.30.6.97 , Vol.30, No.6, 97 ~ 107, 2022
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| Title |
| Effect of pH and Temperature on Cr(VI) Wastewater Treatment Using CoS2 |
| 류하오 Hao Liu , 장성호 Seong-ho Jang , 김고은 Go-eun Kim , 박진식 Jin-sik Park , 이재용 Jae-yong Lee , 조한진 Han-jin Cho , 류재용 Jae-yong Ryu |
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| Abstract |
| The effective treatment of wastewater containing toxic substances produced by human activity continues to be a pressing issue, particularly given the increasingly serious water shortages that occur globally due to development pressure and climate change. In particular, Cr(VI) has been identified by many governments worldwide as a priority pollutant for treatment due to its wide distribution and toxic effects. Thus, there is a need to develop efficient removal methods for this pollutant, including the design of materials with water purification functions. In this study, cobalt sulfide (CoS2) was used to remove Cr(VI) from water. After 120 min at room temperature (25℃), 30 mg of CoS2 removed 4.24, 2.68, 2.44, 1.28, and 1.80 mg/L Cr(VI) at a pH of 2, 4, 6.5, 9, and 11, respectively. At pH 2, the Cr(VI) removal efficiency of CoS2 increased with a higher reaction temperature (19.91 mg/L after 90 min at 55℃), while an increase in the initial concentration of Cr(VI) facilitated the greater removal of Cr(VI) by CoS2 at pH 11. The results of total chromium testing indicated that there were two mechanisms for the removal of Cr(VI) by CoS2 at pH 2 and pH 11. At pH 2-9, HCrO4 - ions attract electrons on the surface of CoS2 and react with hydrogen ions to form water-soluble Cr(III) cations and water. At pH 11, Co3+ on the CoS2 surface reacts with hydroxide ions to generate Co(OH)3 flocs that adsorb Cr(VI) ions from the solution. The results of this study collectively demonstrate that CoS2 is effective in the treatment of Cr(VI) at pH 2 and pH 11 and has broad potential for use in a range of applications. |
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| Key Words |
| CoS2, Cr(VI), Catalysis, Chemical reduction, 이황화코발트, 6가 크롬, 촉매 반응, 화학환원반응 |
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