Preparation and characterization of clay hybrid adsorbents for the removal of paracetamol from model wastewater: A comparative study

Paracetamol, an emerging contaminant, in low concentration (ng/L to mg/L), is discharged as a pharmaceutical residue from wastewater plants into water bodies, endangering flora, fauna, and human health through bioaccumulation. Various adsorbents like titania (S1), silica (S2), titania and silica clay composites (S3 and S4) and montmorillonite K10, (S5) were tried for paracetamol uptake in a model wastewater system. All adsorbents were prepared by a sol-gel route at room temperature and were characterized by Fourier Transform Infra-Red, X-ray diffractometer, Scanning Electron Microscope, and Brunauer-Emmett Teller for the nature of functional groups, structure, and specific surface area. The silica clay composite (S4) showed a mesoporous network with an average pore diameter of 3.5 nm, leading to 74% removal of PCT in fifteen minutes of batch adsorption run time. A pseudo second order kinetic model was found fit for S4 with no formation of PCT metabolite as residue as observed from UV spectra. The maximum adsorption capacity of S4 was 1.86 mg/g of the silica clay composite material. • Synthesis of benign mesoporous silica clay composite for the removal of paracetamol. • Synthesis route is economical and less energy consuming that can be easily escalated to industrial application. • Pseudo second order kinetics was proposed for the adsorption process. • PCT metabolite, if formed was adsorbed by the silica clay composite adsorbent. • Adsorptive capacity of silica clay composite was found to be 1.9 mg/g of the adsorbent material.