Cobalt ferrite/cellulose membrane inserted catalytic syringe filter for facile in-situ filtration/degradation of emerging organic pollutants in water via activating peroxymonosulfate

Abstract

In this study, a novel membrane was prepared from CoFe2O4 deposited commercial cellulose filter paper, and employed in the design of a catalytic syringe filter. The filter was used for the removal of various synthetic organic chemicals (SOCs) including rhodamine B, dimethyl phthalate, bisphenol A, ibuprofen, norfloxacin, 4-chlorophenol and diclofenac in water through in-situ activating peroxymonosulfate, which simulated an actual syringe-driven filtration process. The impact of SOC concentration, injection speed, series-connected filter number on the in-situ filtration/degradation performance of the filter were systematically investigated. The results demonstrated that the prepared filter had excellent catalytic capability towards all mentioned SOCs. Specifically, three series-connected filters could completely degraded SOCs even when the concentration of each SOC was higher than 0.1 mM. ESR and quenching tests indicated that the ·OH and SO4−· were main radical species dominating the SOC degradations. Meanwhile, high-valent metal-oxo species were also generated which participated in the SOC degradations. Furthermore, the filter had promising longtime use stability which maintained its effectiveness for 2 h of uninterrupted water flow. This study provides a facile and practical means to introduce advanced oxidation techniques for organic pollutant removals in actual wastewater through syringe-driven in-situ membrane filtration/degradation process.

Keywords

• Catalytic filter
• In-situ filtration/degradation
• Peroxymonosulfate activation
• High-valent metal-oxo species
• Organic pollutants