Effect of acid and alkaline treatment on the adsorption capacity of cuttlefish bone

As a center of textile industry in Indonesia, city of Pekalongan faces environmental issue due to wastewater effluent from textile industry. The wastewater from textile industry contains dye, mostly synthetic dye, used for coloring the fabrics. One of the dyes commonly used is sulphur blue for producing dark blue color. One of simple methods to reduce the dye in the wastewater is adsorption. Cuttlefish bone was used as the adsorbent. It is abundantly available and cheap because it is a waste of fishing industry. The effect of acid and alkaline treatment to the cuttlefish bone on its adsorption capacity toward sulphur blue dye was investigated. The acid and alkaline treatments were conducted using hydrochloric and sodium hydrochloric solutions, respectively. The concentrations of both solutions were varied (0.0 N, 0.25 N, 0.5 N, 0.75 N, 1.0 N). The concentration of acid and alkaline affect the adsorption capacity of the cuttlefish bone. The cuttlefish bone treated with 0.25 N hydrochloric solution is able to reduce the concentration of the dye solution from 217.67 to 87.67 Pt-Co, while that treated with 0.25N sodium hydroxide solution lowers the concentration of the dye solution to 74.33 Pt-Co. The alkaline-treated cuttlefish bone showed higher adsorption capacity than the acid-treated cuttlefish bone.