Removal of Cadmium Ions from Aqueous Solutions Using Acid-Activated Cockle Shell Powder

• Published in: Materials science forum Vol. 987; pp. 129 - 134
• Main Authors: Nguyen, Tuan Anh, Phung, Thanh Khoa, Le, Tan Phat
• Format: Journal Article
• Language: English
• Published: Pfaffikon Trans Tech Publications Ltd 01.04.2020
• Subjects: Adequacy; Adsorbents; Adsorption; Aqueous solutions; Cadmium; Cockles; Heavy metals; Ion concentration; Mollusks; Response surface methodology; Variance analysis; Wastewater treatment; Water pollution; Adsorption; Cadmium Removal; Acid Activation; Cockle Shell
• ISSN: 0255-5476; 1662-9752; 1662-9752
• DOI: 10.4028/www.scientific.net/MSF.987.129

In Vietnam, heavy metal removal from aqueous solution has been the subject of great attention in the last few years. There are several methods have been developed to reduce heavy metal pollution problems and adsorption technique has been widely used due to the versatility and effectiveness. Cockles are marine bivalve mollusks, whose shell are discharged as wastes by many marine product manufacturers and restaurants. Cockle shell can be economically used as adsorbent for the wastewater treatment. In this study, acid-activated cockle shell was used as an adsorbent material for divalent cadmium ion removal from waste water. The experiments in this work used batch mode adsorption. Experiments were designed by response surface methodology (RSM) and a quadratic model was used to predict the removal efficiency of cadmium. The input to the model was varied as initial cadmium ion concentration from 600 to 1000 mg/L, contact time from 30 to 90 minutes, adsorbent dosage from 0.5 g/L to 1.5 g/L. Analysis of variance was incorporated to judge the adequacy of the models. The predictions of the model were in good agreement with experimental results and the optimal condition is then estimated from the model. Other properties of obtained materials were also investigated using XRD, BET, TGA, SEM analysis methods. The results show that the simple acid-activated cockle shell can be used as a low cost and effective adsorbent for cadmium ion removal.