GONGGONG SHELLS WASTE UTILIZATION AS METHYLENE BLUE DYE BIOSORBENT

• Main Author: Setyo Raharjo, Hagung
• Format: Final Project
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/77406
• Institution: Institut Teknologi Bandung

Methylene blue (MB) dye is a heterocyclic aromatic dye compound which is widely used in the textile, paper and medical treatment industries. The increasing demand for dyes produces dye waste which is harmful to the environment because it is carcinogenic and toxic. Dissolved methylene blue in water can cause a reduction in dissolved oxygen levels, thereby disrupting the ecosystem and can cause health problems ranging from hemolytic anemia to changes in skin color for humans. Based on these problems, an efficient methylene blue remediation method is needed through the adsorption process. One of the natural adsorbents for dyes is seashells. Gonggong clam (Laevistrombus canarium) is a mollusk gastropod that lives in the Bintan, Riau Islands. L. canarium is used as a food commodity which its shelss waste can be utilized in the scope of the craft and fishing industry. The unused Gonggong shell waste can be further processed as methylene blue biosorbent. Gonggong clam shells contain many carbonate groups which can act as adsorbents for coloring compounds in the waters. The weakness of the biosorbent is low adsorption capacity that can be increased by activation through the calcination process. This study aims to evaluate the adsorption performance of calcined Gonggong clam shells as a biosorbent of methylene blue compounds. The calcination process was carried out using an electric furnace at 700°C for 6 hours. The results of the FTIR characterization showed that the absorption peak of the Ca-O vibration at wave numbers 400-580 cm?1 was the absorption of calcium oxide resulting from the decomposition of calcium carbonate. The calcined adsorbent diffractogram shows lower crystallinity so that it is possible to have a larger surface area This is shown by SEM image at 8.000× magnification that there are pores on the surface of the adsorbent. The EDS spectrum shows activated biosorbent composed of elements calcium and oxygen which indicates the success of the calcination process. Zeta Potential value of -5,5 mV shows that the surface of the adsorbent is negatively charged so that it can become an MB adsorbent which is a cationic dye. Optimum adsorption conditions for MB by activated Gonggong clam shells biosorbent 700°C were at pH 10 with a contact time of 90 minutes using 20 mg adsorbent. Adsorption fulfill the pseudo 2nd order adsorption kinetics model and the Langmuir isotherm model with a maximum adsorption capacity of 293,58 mg/g.