The global situation in the decrease of fossil fuels and other non-renewable energy sources is now of signifi cant concern. Interest in renewable energy is increasing from this situation. The oil palm (Elaeis guineen L.) is known as a sustainable energy source for biodiesel production. It is more versatile than other oil crops and provides a higher yield for less energy input [9]. Highly colored palm oil mill effl uent (POME) generates approximately 60% of global crude palm oil [10]. Today the oil palm is an important economic crop in southern Thailand, and in 2016 oil palm plantations covered an area of 720,000 ha. A recent report by the National Science and Technology Development Agency (NSTDA) indicated that Thai agriculturists produced 9 million tons per year of fresh fruit bunches (FFB), with 0.19 tons of POME released from every ton of FFB. Consequently, around 1.026 million tons of darkcolored POME was produced annually. Raw POME is a highly polluting wastewater containing 95-96% colloidal suspensions, 4-5% total solids, and 0.6-0.7% palm oil. The oxidation of phenolic compounds such as lignin and anaerobically degraded products result in the dark Pol. J. Environ. Stud. Vol. 27, No. 1 (2018), 39-44 AbstractLignin-modifying enzymes have long been used in palm oil mill effl uent (POME) treatment to remove the dark brown colour resulting from phenolic contamination. This study investigated a cost-effective industrial application method for optimizing phenol removal from POME using the termite-associated yeast Galactomyces reessii obtained from the subterranean termite under laboratory conditions. The yeast was cultured in POME, and the activity of the ligninolytic enzymes (laccase and manganese peroxidase) was monitored by spectrophotometry. Optimal conditions were achieved using a Box-Behnken experimental design. Results demonstrated that G. reessii reduced the phenolic compounds in POME by 88.69% with growth in 100% (v/v) POME using 30% (w/v) consortia and 5% (w/v) calcium carbonate (CaCO 3 ) at room temperature 30 1C for seven days. G. reessii showed high performance for phenolic removal and decolourization of POME and other industrial wastewaters.

and current density of 278 mA/m 2 , and a 70% increase in half-cell potential. This study demonstrated the capability of laccaseproducing yeast Galactomyces reessii as a biocatalyst on the cathode of the two-chamber lbMFC.

A cost-effective biochar derived from rubber tree sawdust was prepared by low-temperature pyrolysis at 500ºC for 2 h. The biochar was placed as an anode electrode in the anode chamber of the novel model ceramic-separator microbial fuel cell (CMFC) with a laccase-based air cathode. The rubber wastewater (with 500 mg/L sulfate and 1000 mg/L COD) was used as an anolyte. Maximal volumetric power density (PD) of 3.26±0.08 µW/m 3 , maximal volumetric current density of 3.20±0.07 mA/m 3 , and system internal resistance of 1002 Ω were obtained. The post-treatment results showed sulfate removal and COD removal efficiencies of 88.26±1.29% and 89.77±0.45%, respectively. Our work provided a novel model of a low-cost and economically friendly MFC system. Moreover, this work demonstrated a potential route based on sustainable and economical biochar as a bio-anode for wastewater treatment in an MFC.

Aim of the study: This study aims to develop the novel model of multi-electrode MFC with the termite-associated yeast G. reessii for MG decelorization and electricity generation. Material and methods: The termite-associated yeast G. reessii was inoculated into modified midia with 150 mg/L MG. The laccase activity and MG removal was studied. Then, the G. reessii was immobilized on anode surface. The electrical properties and color removal were tested. Results and conclusions: The results showed it successfully removed the MG with 98.15±0.92% within 1 day of operation. Moreover, the OCV, CD and PD of 550.00±10.00%, 3.90±0.10 A/m3 and 1.52±0.08 W/m3 were achieved. Therefore, the system could have the potential for treatment of high concentration MG contaminated wastewater and produce a bio-electric energy.

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.

Palm oil milled effluent (POME) is one of the most environmental concerned industrial wastewater owing to its complex structure. Melanoidin is a highly stable content in POME that caused the dark color. In this study, the Galactomyces sp. rich consortium TM11 with high laccase activity was used to remove a contaminated melanoidin from raw POME. Besides, the single chamber ceramic microbial fuel cell (sCMFC) was developed to eliminate melanoidin and simultaneously generate electrical power. The results indicated that the maximal current density and power density of 215.56±5.09 mA/m2 and 139.44±6.56 mW/m2 were reached. Whereas the melanoidin removal of 83.50±2.93%  was obtained. This study was the first reported of using laccase producing yeast comsortium to remove melanoidin and generate electrical power.

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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.