Evaluation of the use of shellfish shells (Anomalocardia flexuosa) as an adsorbent for textile effluent treatment

An experimental study

Abstract

The objective of this study was to evaluate the use of shellfish shell waste as an adsorbent in the treatment of textile effluent. The collected shells were washed with running water and dried in an oven. Part of the washed and dried shell was crushed and sieved to obtain grains of 0.6 mm, while the remaining portion was ground, thermally treated in a muffle furnace, and sieved to obtain grains of 0.3 mm. The point of zero charge of the adsorbent was determined, and the equilibrium of the solution was performed by preparing solutions containing 50 ml of raw textile effluent and varying masses of each bioadsorbent (1, 2, and 3 g) at different pH values (7.19 and 9.00). The solutions were stirred and then filtered through qualitative absorbent paper. The color, turbidity, and adsorption capacity were measured and calculated. Based on the best result found for the mass of bioadsorbent used, it was added to a solution of 50 ml of raw effluent and stirred for 0, 5, 10, 20, 30, 40, 50, and 60 minutes. The samples were filtered, and the color and turbidity of each were measured, with the adsorption capacity recalculated. The results showed that the calcined shell achieved better results than the natural shell, with the optimal masses being 1.0 g and 2.0 g, respectively. The pH of the solution had little influence on the results. As for the contact time, the best results were observed between 0 and 20 minutes.