SYNTHESIS OF MGFE LAYERED DOUBLE HYDROXIDE (MGFE-LDH) AND MGFE CALCINED LAYERED DOUBLE HYDROXIDE (MGFE-CLDH) USING BITTERN AS MAGNESIUM PRECURSOR AND THEIR APPLICATION AS ANTIBIOTIC ADSORBENT

• Main Author: Najla Izzati, Razita
• Format: Final Project
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/82970
• Institution: Institut Teknologi Bandung

Amoxicillin is one of the most widely used antibiotics for medical treatment. Contamination of this type of antibiotic has been frequently found in groundwater and surface water. One of functional material that can be used to address amoxicillin contamination in the environment is MgFe-LDH. MgFe-LDH is a type of lamellar compound with interlayer spaces in its structure that have the potential as an adsorbent for amoxicillin. Salt production in Indonesia generates up to two million liters of bittern per day. Bittern is a byproduct of the salt industry process, containing high levels of inorganic ions, particularly magnesium, around 10,000 60,000 mg/L. Thus, unused bittern can be utilized as a precursor in the production of functional materials. In this study, MgFe Layered Double Hydroxide (MgFe-LDH) and MgFe Calcined Layered Double Hydroxide (MgFe-CLDH) were synthesized using bittern as the magnesium precursor. The synthesis method for MgFe-LDH and MgFe-CLDH was the co-precipitation method at pH 12 with a ratio of Mg: Fe is 3:1. The crystallinity degree, morphology and size, surface functional groups, and surface area of MgFe-LDH and its calcined product were characterized using Powder X-Ray diffraction (PXRD), Scanning Electron Microscopy (SEM), Fourier-Transform Infrared Spectroscopy (FTIR), and nitrogen adsorption-desorption methods (Brunauer–Emmett–Teller (BET)). The adsorption capability of MgFe-LDH and MgFe-CLDH as antibiotic adsorbents was tested using amoxicillin as a model antibiotic, which is one of the most commonly used penicillin antibiotics. The antibiotic adsorption study included adsorption pH, adsorption kinetics, adsorption isotherms, and the effect of co-existing ions in a wastewater model measured using a UV-Vis spectrophotometer at a wavelength of 230 nm. The optimal amoxicillin adsorption process occurred at pH 6 for MgFe-LDH and pH 4 for MgFe-CLDH. The amoxicillin adsorption by MgFe-LDH followed a pseudo-second order kinetic model, while MgFe-CLDH, followed a pseudo-first order kinetic model. The adsorption isotherms indicated that both MgFe-LDH and MgFe-CLDH followed the Freundlich adsorption isotherm model. Ions Na+, Mg2+, K+, SO42-, and Cl- slightly affected the adsorption by MgFe-LDH and MgFe-CLDH, while H2PO4- could compete with amoxicillin in the adsorption process. Regeneration was conducted three times for MgFe LDH, showing that the optimum regeneration occurred at the second adsorption with an adsorption capacity of 71.578 mg/g, which increased from the first adsorption of 36.326 mg/g, and decreased in the third and fourth adsorptions to 60.932 mg/g and 30.884 mg/g, respectively. MgFe-LDH and MgFe-CLDH can be synthesized from bittern and can be utilized as adsorbents for amoxicillin.