Adsorption of cibacron red reactive dye using rice husk as adsorbent

Abstract

Textile wastewater containing dyes can pollute aquatic environment. This study utilized rice husk as adsorbent for Cibacron Red reactive dyes which are widely used in textile industries. Husks were made into adsorbent without modification (ATM) and acid modified adsorbent (AMA). The optimum condition was obtained under adsorption time of 30 minutes, 1.0 g of adsorbent, and initial concentration of dye solution was 150 ppm. The optimum condition for AMA was obtained under adsorption time of 60 minutes, 2.0 g of adsorbent, and 150 ppm initial concentration of dye solution. The optimum condition of activated charcoal (AA) as a comparison was 30 minute time of adsorption, 3.0 g of adsorbent, and 150 ppm initial concentration dye solution. Adsorption capacity of ATM, AMA, and AA at the optimum conditions was 2879.00, 6898.30, and 2470.00 μg/g, respectively. Adsorption efficiency of ATM, AMA, and AA at the optimum conditions was 19.86, 91.71, and 40.51%, respectively. All three types of adsorbent followed the Freundlich isotherm. Application of the adsorbent on waste of textile manufacture showed a decrease in colour after adsorption by ATM, AMA, and AA, up to 52.05, 98.86 and 48.69%, respectively, with the initial colour intensity of 1485 Pt-Co. Starting with COD of the wastewater which was 7372.0 mg/L, the values decreased after the adsorption with ATM, AMA, and AA were 43.30, 98.56 and 52.58%, respectively. Starting with BOD of 149.09 mg/L, the values decreased after adsorption by ATM, AMA, and AA were 63.41, 76.09, and 72.46%, respectively. Based on these results, rice husk is potentially used as an adsorbent of dyes, thereby reducing the level of pollution of aquatic environment.