Enhancing the efficiency of some agricultural wastes as low-cost absorbents to remove textile dyes from their contaminated solutions

Abstract

Four agricultural wastes, i.e., sugarcane bagasse, rice straw, cotton stalk, and corn stalk were experienced as low-cost lignocellulosic materials for their ability to adsorb reactive red dye from its contaminated solutions. Batch adsorption technology was carried out in order to analyze sorption behavior of dye-adsorbent systems at different wastes, initial dye concentration, and solution pH value. The acid pH treatment was detected to significantly enhance the adsorption efficiency of used lignocellulosic wastes to maximum removal efficiency (96%). Bioreactor technology was applied as up-scaling experiments using sugarcane bagasse (SCB) waste (the best adsorbent under batch experiments) with different adsorbent dosage and flow rates. The maximum removal efficiency (89.65%) was recorded by 448 g of SCB waste, hydraulic retention time of 24 h and 12.6 l/h flow rate. The SEM characterization illustrated accumulation of dye molecules onto lignocellulosic structure. Also, elemental analyses by EDAX instrument confirmed absorption technology. Thus, the sugarcane bagasse wastes can be applied as low-cost and environmental safe absorbent for RR dye removal from its contaminated wastewater and introducing non-traditional water resource.