BIOCONVERSION OF PALM KERNEL OIL (PKO) INTO RHAMNOLIPIDS BY PSEUDOMONAS STUTZERI BK-AB12 MT-03 FOR METHYLENE BLUE DEGRADING PHOTOCATALYSTS

• Main Author: Muhammad Rafif Alwafi, Teuku
• Format: Final Project
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/75537
• Institution: Institut Teknologi Bandung

Environmental pollution by synthetic coloring compounds, such as methylene blue (MB), has become a serious problem worldwide. These coloring compounds are often used in the textile, printing, and paper production industries, resulting in wastewater effluents containing MB. Water pollution by MB can have a negative impact on aquatic ecosystems and human health. Therefore, it is important to treat dye effluents before they are discharged into the external environment. Photocatalysis is one of the practical and efficient methods to treat dye effluents. The photocatalytic mechanism utilizes the help of light and chemical reactions of photocatalysts to break down dyes into substances that are not harmful to living things and ecosystems. This research focuses on testing rhamnolipid, a glycolipid-type biosurfactant, from the bioconversion of palm kernel oil (PKO) by Pseudomonas stutzeri mutant BK-AB12 MT-03 as a photocatalyst to break down MB. In the initial stage, the production and extraction of rhamnolipids using local halophile mutant bacteria Pseudomonas stutzeri BK-AB12 MT- 03 was conducted. PKO was successfully converted into rhamnolipids in the form of yellowish white solids, indicated by the diameter of oil distribution of 5.2 ± 0.3 cm and the acquisition of 23.0 ± 12.8 mg of rhamnolipids per 50 mL of production media. The rhamnolipid yield was confirmed using Fourier Transform Infrared (FTIR) spectrophotometer. FTIR spectra showed that the produced rhamnolipids had functional groups that were specific to rhamnolipids. The CMC value of the rhamnolipid sample was obtained at 47.4 mg/L with a decrease in water surface tension up to 27.2 mN/m. To prove the photocatalytic performance of rhamnolipid, the degradation efficiency of MB was observed using UV-Vis spectrophotometry. Optimization of MB degradation photocatalytic reaction conditions was carried out by varying the rhamnolipid concentration, pH, and salt content. The optimization results showed that the optimum rhamnolipid concentration for this reaction was 1056,61 mg/L with a first-order reaction rate constant of 0,0121 min-1 and a maximum degradation efficiency of 87.51 ± 0.74% under visible light irradiation.