Enhancement of urea removal from reclaimed water using thermally modified spent coffee ground biochar activated by adding peroxymonosulfate for ultrapure water production. (April 2022)

• Record Type: Journal Article
• Authors: Zhang, Xinbo; Yang, Yuanying; Hao Ngo, Huu; Guo, Wenshan; Long, Tianwei; Wang, Xiao; Zhang, Jianqing; Sun, Fengxia
• Is Part Of: Bioresource technology. Volume 349(2022)
• Publication Date: 2022-04
• Subjects: Spent coffee ground -- Biochar -- Ultrapure water -- Urea -- Persulfate activation; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2022.126850
• Languages: English
• ISSNs: 0960-8524

Abstract

Graphical abstract: Highlights: Biochar modified by secondary pyrolysis can act as an activator with low cost. The catalysis system demonstrated excellent performance in degrading urea (94.4%). Carbonate and phosphate were conducive to activating peroxymonosulfate. C–O and –OH can provide electrons and activate peroxymonosulfate. The radical pathway (mainly OH ) dominated the urea removal mechanism. Abstract: To enhance the degradation of urea in reclaimed water for producing ultrapure water (UPW), thermally modified biochar (TBC) was prepared by secondary pyrolysis using spent coffee biochar with the function as an activator of peroxymonosulfate (PMS). Results showed that 94.4% of urea can be degraded effectively by the TBC-PMS system at the dosage of 0.4 g/L TBC and 2 g/L PMS under neutral and weak acid conditions. Moreover, urea removal mainly depended on the free radical pathway (SO4 − and OH ), especially OH . The inorganic anions of TBC increased via secondary pyrolysis, especially carbonate and phosphate, resulting in higher electrical conductance (EC) value than the original biochar. It was conducive to activating PMS. As well, C–O, –OH worked as an active site in the TBC-PMS system, providing electrons and activating PMS. This work provides a novel strategy for UPW production using TBC-PMS system.