Zhu J, Wang S, Li H, Qian J, Lv L, Pan B. Degradation of phosphonates in Co(II)/peroxymonosulfate process: Performance and mechanism.
WATER RESEARCH 2021;
202:117397. [PMID:
34246991 DOI:
10.1016/j.watres.2021.117397]
[Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 06/14/2021] [Accepted: 06/26/2021] [Indexed: 06/13/2023]
Abstract
The increased release of phosphonates to natural waters causes global concern due to their potential threat to the aquatic environment. It is curial to mineralize phosphonates to orthophosphate (PO43-) before they are thoroughly removed from wastewater via conventional biological treatment. In this study, we systematically investigated the performance and mechanism of degradation of phosphonates in Co(II)-triggered peroxymonosulfate (PMS) activation process. The degradation efficiency of various phosphonates is highly dependent on their coordination with Co(II). Using 1-hydroxyethane 1,1-diphosphonic acid (HEDP) as a target pollutant, the Co(II)/PMS process is effective in a broad solution pH range from 5.0 to 10.0. Multiple experimental results imply that Co(II)-PMS complex is the primary reactive species, while hydroxyl radicals (HO•), sulfate radicals (SO4•-), singlet oxygen (1O2) and Co(III) play as the secondary reactive species for the degradation of HEDP. The presence of Cl-, HCO3-, and natural organic matters (NOM) inhibits the degradation of HEDP. However, in real water samples, the selectivity and efficiency for HEDP removal in the Co(II)/PMS process are higher than that in free radicals-mediated advanced oxidation processes. This study not only sheds new lights on the mechanism of Co(II)-triggered PMS activation process, but also provides feasible technology for the degradation of phosphonates in wastewater.
Collapse