Removal of arsenic (III) and arsenic (V) using copper exchange zeolite‐a

Abstract

In this work, modification of zeolite‐A was performed by ion exchange method using copper salts and the copper exchanged zeolite (CEZ) was used for removal of Arsenic (III) and Arsenic (V) from water. The adsorption capacity of zeolite‐A was significantly improved after modification by copper. CEZ removes more than 98% of both As (III) and As (V) from monocomponent solutions. The material was characterized by powder X‐ray diffraction (XRD) and scanning electron microscopy (SEM). XRD pattern shows loss in crystalline structure after copper incorporation which is evident from the decrease in intensity of characteristic peaks of zeolite‐A. SEM images shows that cubical morphology characteristic of zeolite‐A has been distorted after copper incorporation. Various isotherm and kinetic models were used to determine adsorption and kinetic parameters and to delineate the probable mechanism of adsorption. The data revealed that adsorption of arsenic on CEZ followed Langmuir model with maximum sorption capacity of 1.37 and 1.48 mg/g at 30°C for As (III) and As (V), respectively. CEZ effectively removes arsenic from water at wide pH range of 3–10 and in the presence of interfering ions namely phosphate, sulfate, nitrate, carbonate, and bicarbonate which is evident from tap water study. CEZ appears to be a promising adsorbent for removing arsenic from water. The water quality after treatment with CEZ also confirms that it is safe for drinking purpose and within the permissible limits as per World Health Organization guideline values and Indian drinking water standards. © 2014 American Institute of Chemical Engineers Environ Prog, 33: 1274–1282, 2014