Engineered ball-milled colloidal activated carbon material for advanced oxidation process of ibuprofen: Influencing factors and insights into the mechanism

Abstract

This study explores a simple and efficient, physically modified ball-milled activated carbon (ACBM) preparation from granular activated carbon (GAC), which can be demonstrated for groundwater application. The colloidal stability of the ACBM plays a vital role in the activation of peroxymonosulfate (PMS) and the degradation of pollutants. Adsorption kinetics and isotherm studies explain that the ACBM has more active sites and maximum adsorption capacity (qmax = 509 mg g−1) on the surface of the materials than GAC. The 92% of ibuprofen degradation was achieved at 240 min along with 0.1 g L−1 of ACBM, 5 mM of PMS, and 6.3 of initial solution pH. A chemical scavenger and electron spin resonance spectra also confirmed the formation of reactive oxygen species such as radicals (O2•–, HO•, SO4•–) and non-radical (1O2) in the ACBM/PMS system. Three major degradation pathways, hydroxylation, demethylation, and decarboxylation involved in ibuprofen degradation. Nearly 13 degradation by-products were detected during the ACBM/PMS oxidation of ibuprofen. The toxicity analysis of oxidation by-products of ibuprofen was also discussed by computational simulation employing the ecological structure-activity relationships software. The ACBM/PMS system was successfully applied to the natural groundwater system for ibuprofen degradation. Hence, the ACBM/PMS system is an excellent catalyst for real groundwater applications.