Sorption process of municipal solid waste biochar-montmorillonite composite for ciprofloxacin removal in aqueous media. (December 2019)

• Record Type: Journal Article
• Authors: Ashiq, Ahmed; Sarkar, Binoy; Adassooriya, Nadeesh; Walpita, Janitha; Rajapaksha, Anushka Upamali; Ok, Yong Sik; Vithanage, Meththika
• Is Part Of: Chemosphere. Volume 236(2019)
• Publication Date: 2019-12
• Subjects: Emerging contaminants -- Biochar -- Antibiotics -- Wastewater -- Pharmaceuticals; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2019.124384
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: This study evaluates a novel adsorbent for ciprofloxacin (CPX) removal from water using a composite derived from municipal solid waste biochar (MSW-BC) and montmorillonite (MMT). The composite adsorbent and pristine materials were characterized using powder X-Ray Diffraction (PXRD), Fourier-Transform Infrared (FTIR) spectroscopy, and Scanning Electron Microscope (SEM) before and after the adsorption. Batch experiments were conducted to study the mechanisms involved in the adsorption process. Ciprofloxacin sorption mechanisms were interpreted in terms of its pH-dependency and the distribution coefficients. The SEM images confirmed the successful binding of MMT onto the MSW-BC through flaky structure along with a porous morphology. Encapsulation of MMT onto MSW-BC was exhibited through changes in the basal spacing of MMT via PXRD analysis. Results from FTIR spectra indicated the presence of functional groups for both pristine materials and the composite that were involved in the adsorption reaction. The Hill isotherm model and pseudo-second-order and Elovich kinetic models fitted the batch sorption data, which explained the surface heterogeneity of the composite and cooperative adsorption mechanisms. Changes made to the MSW-BC through the introduction of MMT, enhanced the active sites on the composite adsorbent, thereby improving its interaction with ionizable CPX molecules giving high sorption efficiency. Graphical abstract: Image 1019974 Highlights: Biochar composite was prepared using municipal solid waste and montmorillonite. Ciprofloxacin adsorbed more efficiently on the composites than pristine materials. The primary mechanism for adsorption is π -induced electrostatic interactions.