Treatment of Wastewater Containing Hexavalent Chromium Using Zeolite Ceramic Adsorbent in Adsorption Column

Abstract

Natural Zeolites in powdered form have commonly used as adsorbent and one of the most crucial compound in water treatment plant, in filter system of petrochemicals or other processes under environmentally, physically and chemically conditions. But in the form of powder, zeolites are easily washed out in liquid or gas stream. Therefore, a modification would be necessary to solve this problem. Zeolites and clay were modified into ceramic adsorbent to adsorb heavy metal pollutant that is hexavalent chromium Cr (VI) contained in electroplating industrial effluents. Zeolite and clay were mixed evenly and molded into small balls with 5-6 mm diameter and dried at 1000 o C for 48 hrs. This adsorbent was activated with HCl 32% solution for 1 hr to enhance its adsorption potential. Ten samples with various ratios of zeolite:clay (3:37-12:28) with the total adsorbent mass of 1000 g was examined. Cr (VI) uptake in liquid wastewater was studied by varying contact time and the ratio of zeolite and clay. The effect of activation treatment with HCl 32% solution on adsorption performance of zeolite ceramic adsorbent was also investigated. Analysis of wastewater output indicates a reduction of hexavalent chromium concentration reaches 99.45% at contact time 10 h with 12:28 ratio of activated adsorbent. This shown that the process of adsorption had greatly reduced the contamination of Cr (VI) and may have been a solution for environment problem regarding wastewater containing Cr (VI).