Recycling scale inhibitor wastes into pH-responsive complexes to treat wastewater produced from spent lithium-ion battery disposal

• Published in: Water research (Oxford) Vol. 260; p. 121939
• Main Authors: Zhang, Jiawen, Ge, Qingchun
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 15.08.2024
• Subjects: Draw solute; Forward osmosis; Organophosphorus-containing wastewater; pH-Responsive complex; Spent lithium-ion battery; Spent lithium-ion battery; Draw solute; Forward osmosis; pH-Responsive complex; Organophosphorus-containing wastewater
• ISSN: 0043-1354; 1879-2448; 1879-2448
• DOI: 10.1016/j.watres.2024.121939

•pH-responsive ZnATMP-iNa (i = 0, 1, 2, 3, 4) are developed from wastes for FO wastewater purification.•ZnATMP-3Na outperforms the reported draw solutes with higher water fluxes and smaller solute losses.•The ZnATMP-3Na facilitated FO system efficiently treats wastewater produced in lithium-ion battery disposal.•ZnATMP-3Na is readily recycled via pH-regulation and can be reused to FO for water purification. A large amount of organophosphorus-containing wastewater is produced in spent lithium-ion battery disposal. Forward osmosis (FO) offers unique advantages in purifying this kind of wastewater if suitable draw solutes – the core of FO technology, are available. Herein we synthesize several pH-sensitive zinc complexes, namely ZnATMP-iNa (i = 0, 1, 2, 3, 4), from ZnSO4 and amino tris(methylene phosphonic acid) (ATMP) obtained from scale inhibitor wastes for organophosphorus-containing wastewater remediation. Among these ZnATMP-iNa, ZnATMP-3Na best meets the standards of an ideal draw solute. This makes ZnATMP-3Na outperform other reported draw solutes. 0.6 M ZnATMP-3Na produces a water flux of 12.7 LMH, 136 % higher than that of NaCl and a solute loss of 0.015 g/L, lower than that of NH4HCO3 (0.83 g/L). In organophosphorus-containing wastewater treatment, ZnATMP-3Na has higher water recovery efficiency (8.3 LMH) and sustainability than NaCl and NH4HCO3, and is sufficient to handle large quantities of wastewater. Remarkably, the pH-responsive property allows ZnATMP-3Na to be readily recovered through pH-control and reused in FO. The ionic property, expanded cage-like structure and easy-recycling make ZnATMP-3Na achieve sustainable FO separation and superior to other draw solutes. This study provides inspiration for draw solute design from wastes and extends FO application to organophosphorus-containing wastewater remediation. [Display omitted] pH-responsive draw solution is employed in FO separation to treat wastewater produced from spent lithium-ion battery disposal.