Importance of iron complexation and floc formation towards phosphonate removal with Fe-electrocoagulation

Hu, Haiyang; Song, Bingnan; Lei, Yang

2024-09-15

10.1016/j.watres.2024.122117

WATER RESEARCH   影响因子和分区

0043-1354

1879-2448

Phosphonates are widely used scale inhibitors, but the residual phosphonates in drainage are challenging to remove because of their chelating capacity and resistance to biodegradation. Here, we reported a highly efficient and robust Fe-electrocoagulation (Fe-EC) system for phosphonate removal. Surprisingly, we found for the first time that phosphonates like NTMP were more efficiently removed under anoxic conditions (80% of total soluble phosphorus (TSP) in 4 min) than oxic conditions (0% of TSP within 6 min) in NaCl solution. A similar phenomenon was observed when other phosphonates, such as EDTMP and DTPMP, were removed, highlighting the importance of iron complexation and floc formation toward phosphonate removal with Fe-EC. We also showed that the removal efficiency of NTMP by electrochemically in-situ formed flocs (97%) was much higher than postadsorption systems (ex-situ, 40%), revealing that the growth of flocs consumed the active site for NTMP adsorption. Beyond the removal of TSP, 10 % of NTMP-P was also degraded after the electrolysis phase, evidenced by the evolution of phosphate-P. However, this did not happen in anoxic or chemical coagulation processes, which confirms the formation of reactive oxygen species via Fe(II) oxidation in the oxic Fe-EC system. The primary removal mechanism of phosphonates is due to their complexation with iron (hydr)oxide generated in the Fe-EC system by forming a Fe-O-P bond. Encouragingly, the Fe-EC system exhibits comparable or even better performance in treating phosphonate-laden wastewater (i.e., cooling water). Our preliminary cost calculation suggests the proposed system ( 0.009/m3) has a much lower OPEX under oxic conditions than existing approaches. This study sheds light on the removal mechanism of phosphonate and the treatment of phosphonateladen wastewater by playing with the iron complexion and flocs formation in classical Fe-EC systems.

Antiscaling Phosphonate Flocs Iron oxidation Fe-electrocoagulation

SCI ; EI

英语

第一 ; 通讯

Guangdong Basic and Applied Basic Research Foundation[2023A1515110152] ; Shenzhen Science and Technology Program["JCYJ20230807093405011","20220815101937003"] ; SUSTech Start-Up Funding[Y01296128] ; Shenzhen Key Laboratory of Precision Measurement and Early Warning Technology for Urban Environmental Health Risks[ZDSYS20220606100604008] ; High level of special funds[G03050K001]

Engineering ; Environmental Sciences & Ecology ; Water Resources

Engineering, Environmental ; Environmental Sciences ; Water Resources

WOS:001281399500001

PERGAMON-ELSEVIER SCIENCE LTD

20243016760506

Biodegradation ; Chemicals removal (water treatment) ; Coagulation ; Cooling water ; Sodium chloride

Industrial Wastes:452.3 ; Industrial Wastes Treatment and Disposal:452.4 ; Biotechnology:461.8 ; Biochemistry:801.2 ; Chemical Operations:802.3 ; Chemical Agents and Basic Industrial Chemicals:803 ; Chemical Products Generally:804

ENVIRONMENT/ECOLOGY

Web of Science

Southern Univ Sci & Technol, Sch Environm Sci & Engn, Shenzhen Key Lab Precis Measurement & Early Warnin, Shenzhen 518055, Peoples R China

Hu, Haiyang,Song, Bingnan,Lei, Yang. Importance of iron complexation and floc formation towards phosphonate removal with Fe-electrocoagulation[J]. WATER RESEARCH,2024,262.

Hu, Haiyang,Song, Bingnan,&Lei, Yang.(2024).Importance of iron complexation and floc formation towards phosphonate removal with Fe-electrocoagulation.WATER RESEARCH,262.

Hu, Haiyang,et al."Importance of iron complexation and floc formation towards phosphonate removal with Fe-electrocoagulation".WATER RESEARCH 262(2024).