Co-catalytic of aluminosilicate stabilized cobalt for peroxymonosulfate activation to degrade levofloxacin

Stabilization of Co was essential to address its pollution. In this work, geopolymerization was used to stabilize the Co2+ in the presence of alumina-silicate under hydrothermal process, in which the Co2+ is hypothesized to be a substitute of cation to balance the charge. Then the Co2+ could be incorporated into the geopolymer stably being named as AlxSiyCoz-T. Interestingly, the Co2+ stabilized AlxSiyCoz-T was recycled and reused for peroxymonosulfate (PMS) activation. The stability and catalytic activity of the AlxSiyCoz-T in PMS activation was evaluated. Results showed that the alumina and silicate geopolymerization played positive role in Co2+ stabilization, what were determined by the molar ratio of alumina to silicate, hydrothermal process. Besides, the AlxSiyCoz-T performed favorable activity in PMS activation for LEV degradation with an efficiency of 98.84 % and rate constant of 0.1154 min(-1). In this case, the Co2+ was the main catalyst in PMS activation, while the alumina-silicate geopolymerization not only contributed to Co2+ stabilization, but also resulted in the formation of oxygen vacancy. Then the co-catalytic of alumina-silicate in PMS activation was understood by the synergy factor. The Co2+ leaching efficiency of AlSi2Co4-200 is only 0.011 %, confirming the heterogeneous catalytic in PMS activation. The AlxSiyCoz-200 performed favorable stability that could be used for five cycles at least. O-1(2), SO4-center dot and center dot OH contributed to LEV degradation. Thus, the alumina and silicate geopolymerization could play important role in stabilization and co-catalytic for activating PMS, performing the dual effect on waste treatment and resource recycle.