Adsorptive decontamination of antibiotic-spiked water and milk using commercial and modified activated carbons

This study deals with the removal of antibiotics from contaminated water and milk using pristine and modified activated carbons (ACs) from various biomass sources. Pristine ACs exhibited good removal efficiency (RE) for various antibiotics from aqueous solutions and milk. To further enhance adsorption performance, a wood powdered activated carbon (WPAC) was modified by oxidation with H2O2 under shaking (SK), ultrasonication (US) and microwave (MW) heating, as well as MW calcination. As a result, US- and MW-assisted modifications lead to significantly higher adsorption performance for marbofloxacin (MAR) than pristine WPAC. An extended characterization was carried out on pristine and modified ACs to find structure-adsorption capability relationships and the results showed that the adsorption performance was promoted by the presence of newly formed/ converted oxygen-containing functional groups upon modification. These groups rule the adsorption mechanism and the modifications allow adsorbent consumption and treatment costs to be greatly reduced, while providing similar adsorption performance. In particular, the removal of low concentration antibiotics from milk using ACs modified under MW-assisted calcination is efficient, economical and convenient, despite the presence of competition adsorption by impurities. In summary, adsorption using modified ACs is a highly promising technique for the decontamination of antibiotic-polluted water and milk.