ADSORPTION OF DICLOFENAC COMPOUNDS USING MOLECULARLY IMPRINTED POLYMER MODIFIED MAGNETIC PARTICLES (MMIP)

• Main Author: Mukhlasul Amri, Ahmad
• Format: Theses
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/86659
• Institution: Institut Teknologi Bandung

Diclofenac (DCF) is one of the non-steroidal anti-inflammatory drugs (NSAIDs) to relieve inflammation. This drug waste is often found in pharmaceutical waste, hospitals, and domestic waters, causing environmental problems. Medical wastewater treatment plants (WWTPs) report that only 30-70% of DCF is successfully removed. At the same time, the rest remains in the environment and can potentially cause environmental risks and negative impacts on human health. The adsorption method is used as an alternative in DCF separation due to its simple preparation, high efficiency, and relatively low operational cost. Molecularly imprinted polymers (MIPs) are used as adsorbents, due to their advantages in terms of high selectivity, stability, and reusability. MIPs are modified with magnetite (Fe?O?) nanoparticles, which enables efficient separation of the adsorbent from the solution using an external magnetic field. This study aims to synthesize MNIP (non-MIP modified magnetic particles) and MMIP (MIP modified magnetic particles), determine the optimum conditions of adsorption, and test the selectivity and repeatability of MMIP towards DCF. MMIP was synthesized through polymerization based on DCF as the mold molecule, 4 vinylpyridine as the monomer, ethylene glycol dimethacrylate (EGDMA) as the crosslinking agent, and Fe?O? as the core. The structure and composition of the synthesized polymer were characterized using various analytical techniques. XRD results confirmed the diffractogram pattern of the MIP modification with magnetite with a cubic spinel structure of Fe?O? corresponding to the magnetite standard. FTIR spectra showed the presence of typical functional groups, with a peak at 580 cm-¹ indicating the Fe-O functional group of Fe?O? and the modifications to MIP and NIP. In addition, the peak at 3425 cm-¹ indicated the vibrations of the -OH and N-H functional groups of DCF and the peak at 815 cm-¹ indicated the C-Cl functional group of DCF. SEM-EDS and TEM results showed that MNIP and MMIP were spheric, with Fe?O? coated in NIP and MIP. VSM results show that MMIP after leaching has a reduced magnetic saturation compared to pure Fe?O?. Zeta potential results showed that MMIP had a negatively charged surface at pH 5 (optimum pH) with optimum doses of MNIP (1.8 g/L) and MMIP (3 g/L). Adsorption studies revealed that MMIP had a higher maximum adsorption capacity (83.54 mg/g) than MNIP (69.19 mg/g) with the Sips isotherm model. The kinetics study revealed that the adsorption process followed a pseudo second-order kinetics model with optimum contact times of MNIP and MMIP of 45 min and 30 min, respectively. The intra-particle diffusion model indicated that the diffusion stage in the polymer network or pores was the rate determining stage. Thermodynamic analysis revealed that the adsorption process was endothermic and spontaneous, with the adsorption capacity increasing with temperature. MMIP selectivity towards ibuprofen (IBP) and naproxen (NPX), and showed high adsorption capacity towards DCF. Repeatability tests showed that MMIP was able to maintain a stable adsorption capacity for up to five adsorption-desorption cycles. The potential of MMIP as an adsorbent for DCF could be an alternative in the separation of DCF in medical waste.