Textile industry effluents contain several hazardous substances, such as dye-containing effluents, which pose environmental and aesthetic challenges. Presently, the microbial-based remediation process is in use. This study investigated the application of ferrous–ferric oxide (Fe₃O₄) nanoparticles, a readily formulated nanoadsorbent, to remove scattered dye molecules from industrial effluents. The ferrous–ferric oxide nanoparticles were prepared using a chemical co-precipitation method. The nanoparticles had 26.93 emu g⁻¹ magnetization, with sizes smaller than 20 nm, and possessed a highly purified cubic spinel crystallite structure. The catalytic activity of the iron oxide depended on the dose, photocatalytic enhancer, i.e., H₂O₂ level, pH of the reaction medium, and dye concentration. We optimized the Fenton-like reaction to work best using 1.0 g/L of ferrous–ferric oxide nanoparticles, 60 mM oxalic acid at pH 7.0, and 60 ppm of dye. Iron oxides act as photocatalysts, and oxalic acid generates electron–hole pairs. Consequently, higher amounts of super-radicals cause the rapid degradation of dye and pseudo-first-order reactions. Liquid chromatography–mass spectrometry (LC-MS) analysis revealed the ferrous–ferric oxide nanoparticles decolorized and destroyed Disperse Red 277 in 180 min under visible light. Hence, complete demineralization is observed using a photo-Fenton-like reaction within 3 h under visible light. These high-capacity, easy-to-separate next-generation adsorption systems are suggested to be suitable for industrial-scale use. Ferrous–ferric oxide nanoparticles with increased adsorption and magnetic properties could be utilized to clean environmental pollution.

Enzyme-assisted extraction (EAE) method is one of the most environmentally friendly methods of enzyme application in the extraction of bioactive compounds. The purpose of this study was to determine the optimum temperature and time required in the extraction of anthocyanin compounds from purple sweet potato (Ipomoea batatas L.) with and without ?-L-arabinofuranosidase (AbfA) - assisted. The AbfA enzyme was obtained from Saccharomyces cerevisiae recombinant strain BJ1824 contain pYHMI-Af plasmid. The optimum temperature and time in the extraction of anthocyanin compound with and without ?-L-arabinofuranosidase from purple sweet potato were performed on the 40, 50, 60 and 70⁰C; and 150, 180, 210 minutes. The extraction was done by ethanol solvent of 60,32% (v/v) acidified with citric acid of 2,39% (b/v). The measurement of anthocyanin levels using UV-Vis Spectrophotometer at 527 nm and 700 nm wavelengths at pH 1,0 and 4,5. The optimum condition of non-enzyme-assisted extraction was at 60⁰C for 210 minutes, with the anthocyanin levels of 26,3842 mg/L; while with the AbfA enzyme-assisted at 50⁰C for 180 minutes, with the anthocyanin levels of 28,2056 mg/L. The extraction with enzyme-assisted resulted the anthocyanin levels of 6,90% higher than without the using of enzyme.

Organic waste, such as fruit peels, has potential to be processed into useful products, for example through fermentation into garbage enzymes (GE) or also known as eco-enzymes. This study aims to determine 16S rRNA gene fragment amplicon of metagenomic DNA, antibacterial activity against the Staphylococcus aureus and Escherichia coli and cellulase activity from GE of sweet orange (Citrus sinensis) peels. Sweet orange peel was mixed with brown sugar and water in the ratio of 3:1:10 respectively, then fermented for 90 days (GE-90) and 105 days (GE-105). The metagenomic DNA isolate of GE was amplified by polymerase chain reaction (PCR) technique, antibacterial activity was tested using the agar diffusion well method, and cellulase activity was determined by the dinitrosalicylic acid (DNS) method. The results of GE-90 and GE-105 metagenomic DNA amplification using PCR was obtained 16S rRNA gene fragment of about 750 bp. Inhibition effectiveness of undiluted GE-90 against S. aureus and E. coli compared with amoxicillin 0.03% was 76.7 and 71.6%, respectively; while GE-105 was 68.7 and 56.6% respectively. Cellulase activity of GE-90 was 0.01186 ± 0.00077 U/mL; and 0.01384 ± 0.00113 U/mL for GE-105.

Pandan wangi (Pandanus amaryllifolius (Roxb.)) leaves is one of the organic wastes from canang residues commonly found in Bali. The purpose of this study was to Pandan wangi (Pandanus amaryllifolius (Roxb.)) leaves is one of the organic wastes from canang residues commonly found in Bali. The purpose of this study was to