The present paper aims to investigate water purification of phenol by walnut green hull adsorbent. The surface characteristics of adsorbent were studied using Fourier transform infra-red (FTIR), scanning electron microscope, and X-ray diffraction (XRD) techniques. The presence of functional groups such as hydroxyl and carbonyl onto walnut green hull surface were proved by FTIR analysis. Also quartz, cellulose and hematite were detected in the XRD analysis of samples by an X-ray diffractometer. The maximum sorption was achieved at pH 4.0. Data were evaluated for compliance with the Langmuir, Freundlich, Temkin and Dubinin–Radushkevich isotherm models. The results indicate that the data for adsorption of phenol onto walnut green hull fitted well with the Langmuir isotherm. The maximum adsorption capacity of adsorbent was achieved by Langmuir isotherm 17.8 mg g–1. Also, adsorption kinetics of phenol on adsorbent were studied. The rates of sorption were found to conform to pseudo-second-order kinetics with good correlation.
- walnut green hull
- First received 20 May 2015.
- Accepted in revised form 30 November 2015.
- © IWA Publishing 2016