Efficient use of hybrid materials in the remediation of aquatic environment contaminated with micro-pollutant diclofenac sodium

Abstract

The aim of this study is to synthesise indigenously the hybrid materials and their efficient use to treat the wastewater contaminated with one of important micro-pollutant diclofenac. The hybrid materials are obtained modifying the commercial bentonite (B) and locally collected clay (LC) with the hexadecyltrimethylammonium bromide (HDTMA) as to obtain the organo-modified clay samples (BH and LCH). Moreover, the B and LC clay samples are pillared with aluminium and modified with the HDTMA as to obtain inorgano–organo-modified clay hybrid materials (viz., BAH and LCAH solids). The hybrid materials are characterised by the XRD (X-ray diffraction) and FT-IR (Fourier Transform Infra-Red) analytical methods and the surface morphology is obtained by the FE-SEM (Field Emission Scanning Electron Microscope) images of these solids. pHPZC (Point of Zero Charge) of these solids is obtained by acid base titrations. Further, these materials are assessed in the efficient and effective treatment of aquatic environment contaminated with diclofenac sodium under the batch and fixed-bed column reactor operations. Batch data is obtained for various physico-chemical parametric studies viz., the effect of solution pH (3.8–10.0), sorptive concentrations (1.0–20.0mg/L), and background electrolyte concentrations (0.0001–0.1mol/L NaCl). The kinetics of the uptake of diclofenac by these solids is conducted using the pseudo-first, pseudo-second and fractal-like-pseudo-second order non-linear rate equations. The rate constants along with the removal capacity are, therefore, estimated. Further, the fixed-bed column reactor operations are performed to obtain the loading capacity of column for diclofenac under the dynamic conditions.