The ceramic separator has been interested in low-cost alternative proton exchange membranes in a microbial fuel cell (MFC). In this study, the silica-modified ceramic separator has been integrated with the yeast-based MFC for electricity generation and phenol treatment from the winery wastewater. The 30% (w/w) silica powder was mixed with the 70% (w/w) natural clay. The modified ceramic plates (0.2, 0.5, and 1.0 cm of thickness) were prepared at 680°C and used for MFC operation. As an anolyte, synthetic winery wastewater (2,000 mg COD/L and 100 mg/L phenol) with 5% (v/v) ethanol was used. The ethanol-tolerant yeast Pichia sp. ET-KK was used as an anodic catalyst. The results showed the maximal power density of 0.212 W/m2 and phenol removal of 95.05% were reached from the 0.2-thick ceramic plate integrated MFC. This study demonstrated that the silica-modified ceramic separator has a high potential for enhancing electricity generation in the yeast-based MFC.

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The biochar electrode is an alternative low-cost electrode for electricity generation and wastewater treatment by the microbial fuel cell (MFC). In this study, the water hyacinth biochar (WHB) was prepared by pyrolysis at 350ºC and activated by chemical immersion. The activated WHB was integrated with ceramic-separator MFC (CMFC) and used for the pharmaceutical wastewater (containing 100 µg/mL penicillin) treatment and electricity generation. The maximal power output and penicillin removal of 0.032±0.001 W/m 2 and 65.12±0.02% were achieved. This study gained new knowledge of using the WHB electrode coupled with the CMFC for pharmaceutical wastewater treatment and electricity generation.

Stingless bee honey is a nutritious food that contains a variety of vitamins, minerals, enzymes, and antioxidants. It is known to have higher nutritional and medicinal properties compared to honey produced by other bee species. Cider is a well-known functional drink that contains high antioxidants, which can help protect against cellular damage caused by free radicals. This study aimed to investigate the potential of co-fermentation with yeast (Saccharomyces cerevisiae) and bacterium (Lactobacillus sp.) in producing high-antioxidant honey cider when compare with standard antioxidant. The results showed that honey cider co-fermented with both microorganisms for 14 days had significantly higher antioxidant activity (145.27 ± 0.20 µg TE/mL) compared to single culture fermentation (p < 0.05). Gas chromatography-mass spectrometry (GC-MS) analysis revealed the presence of several bioactive compounds in the stingless bee honey cider. These compounds include methylenecyclopropanecarboxylic acid, 2(5H)-furanone, 2-methylbicyclo[4.3.0]non-1(6)-ene, bicyclo[3.1.0]hex-2-ene, 4-methyl-1-(1-methylethyl), D-limonene, benzene, 1-(1-butenyl)-4-methoxy, and phytol. These compounds possess various beneficial activities, such as antioxidant, anti-inflammatory, antimicrobial, and anticancer properties. The identification of these compounds in the stingless bee honey cider suggests that it may have potential health benefits beyond its nutritional value. The co-fermentation approach using S. cerevisiae and Lactobacillus sp. could be considered a promising strategy for developing antioxidant-enriched honey cider with potential health benefits.

Melanoidin is the main cause of the dark brown color of the palm oil mill effluent (POME) that form under the Maillard reaction. In this study, the constructed wetland integrated with microbial fuel cell (CW-MFC) has been developed for melanoidin removal from the POME and simultaneously electricity generation as a by-product. The macrophyte Dieffenbachia sp. has been used as a biocatalyst on the cathode electrode and the oxidoreductase-producing bacterium Bacillus lichenformis with laccase and manganese peroxidase activity has been used as an anodic biocatalyst. The maximal melanoidin removal, chemical oxygen demand (COD) removal, enzyme activity, and power output were monitored. The maximal laccase and manganese peroxidase activities of 1.60 ± 0.10 U/mL and 1.45 ± 0.05 U/mL were found during melanoidin degradation. In addition, the maximal melanoidin removal of 93.59 ± 0.10% and 95.12 ± 0.15% were achieved respectively. When the maximal power density of 0.18 ± 0.01 mW/m3 was generated. This study gained new knowledge about using the CW-MFC system as a biological treatment process of the melanoidin content in the POME and simultaneously generated electrical energy as a by-product. HIGHLIGHTS The coupling process of constructed wetland and the microbial fuel cell is promising for the melanoidin removal of the POME The maximal melanoidin removal of 93.59 % was gained The maximal power output of 0.18 mW/m3 was generated from this system GRAPHICAL ABSTRACT