Synergistic of yeast Saccharomyces cerevisiae and glucose oxidase enzyme as co-biocatalyst of enzymatic microbial fuel cell (EMFC) in converting sugarcane bagasse extract into electricity

The microbial fuel cell (MFC) is an ecologically friendly alternative energy source. Due to the typically limited electron transfer in MFC systems, co-biocatalysts are necessary to enhance their performance. Enzymes are used as co-biocatalysts due to their superior ability to generate energy, and the system is known as an enzymatic microbial fuel cell (EMFC). One of the substrates that may be used is bagasse waste extracted from sugarcane. Saccharo­myces cerevisiae and the enzyme glucose oxidase (GOx) serve as co-biocatalysts in the breakdown of sugarcane bagasse waste in this study, which uses single-chamber EMFCs. In EMFC using sugarcane bagasse waste extract employing S. cerevisiae biocatalyst and glucose oxidase enzyme co-biocatalyst, the open circuit voltage was 0.56 V and the maximum power density was 146.65 mW m-2, an increase of 10.4 times to MFCs that solely employed only yeast biocatalyst. In addition, the chemical oxygen demand (COD) reduction achieved by this technology is 75 %. In addition, the pH of sugarcane bagasse waste extract samples treated with Saccharomyces cerevisiae yeast and GOx enzyme decreased from 4.6 to 4.2. This research demonstrates that adding the co-biocatalyst GOx enzyme may boost the performance of the traditional yeast MFC

Scientometric Analysis of Biofilm Research in Microbial Fuel Cells: Insights into Key Research Areas and Emerging Trends

A scientometric investigation mapped the literature on biofilm development in Microbial Fuel Cells (MFCs), revealing promising renewable energy prospects and waste treatment solutions. The analysis encompassed 16898 sources, predominantly research articles (12571), along with review papers, conference papers, books, and other publications. Network analysis highlighted key research clusters and subtopics, including biofilm characterization, electrode optimization, and monitoring/control technologies. Insights from biofilm research have led to innovative approaches like biofilm engineering and advanced analytical techniques, enhancing real-world applications. Integration of MFCs into sustainable development underscores biofilms' potential as eco-friendly and economically viable components of energy production systems

The Effects of Audible Sound for Enhancing the Growth Rate of Microalgae Haematococcus pluvialis in Vegetative Stage

Physico-stimulant like audible sound is one of the new promising methods for enhancing microalgae growth rate. Here, microalgae Haematococcus pluvialis was cultivated with the addition of audible sound with titles “Blues for Elle” and “Far and Wide.” The objective of this research was to evaluate the effect of audible sound to the growth and productivity of microalgae. The experiment has been conducted by exposing the audible sound for 8 h in 22 days to microalgae cultivation. The result showed that microalgae H. pluvialis treated by the music “Blues for Elle” shows the highest growth rate (0.03 per day), and 58% higher than the one without audible sound. The average number of cells in stationary phase is 0.76 × 104 cells/mL culture and the productivity is 3.467 × 102 cells/mL/day. The pH of microalgae medium slightly decreases because of proton production during photosynthesisprocess. The kinetic rate constant (kapp) is 0.078 per day, reaction half-life (t1/2) is 8.89 days, and catalytic surface (Ksurf) is 1.66 × 10−5/day/cm2. In conclusion, this audible sound is very useful to stimulate microalgae growth rate, especially H. pluvialis

Performance of Yeast Microbial Fuel Cell Integrated with Sugarcane Bagasse Fermentation for COD Reduction and Electricity Generation

The purpose of this analysis is to evaluate the efficiency of the Microbial Fuel Cell (MFC) system incorporated with the fermentation process, with the aim of reducing COD and generating electricity, using sugarcane bagasse extract as a substrate, in the presence and absence of sugarcane fibers. There is a possibility of turning bagasse extract into renewable bioenergy to promote the sustainability of the environment and energy. As a result, the integration of liquid fermentation (LF) with MFC has improved efficiency compared to semi-solid state fermentation (S-SSF). The maximum power generated was 14.88 mW/m2, with an average COD removal of 39.68% per cycle. The variation margin of the liquid fermentation pH readings remained slightly decrease, with a slight deflection of +0.14 occurring from 4.33. With the absence of bagasse fibers, biofilm can grow freely on the anode surface so that the transfer of electrons is fast and produces a relatively high current. Experimental data showed a positive potential after an effective integration of the LF and MFC systems in the handling of waste. The product is then simultaneously converted into electrical energy. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Photo-bioelectrochemical cell anodes enhanced with titanium oxide, carbon nanotubes and chlorophyll-based catalyst on different supporting materials

An important part of a photo-bioelectrochemical cell (PBEC) is the photo-biocatalyst substrate taken as anode. This study aims to explain the effect of CNT/TiO2/chlorophyll photocatalyst coated on the cellulose nanopaper (CNP) substrate on the PBEC performance and to compare the results with those obtained for the commercial indium tin oxide (ITO) glass and flexible ITO as substrates. The results showed high sheet resistance of CNP, which is 61182 Ω sq-1, which is reduced by 80 % in the presence of CNT/TiO2/Chl biocatalyst. The highest output voltage of 0.95 to 1 V was produced by coating CNT/TiO2/Chl on the flexible ITO. The maximum current density (Jmax) of 3726 mA m-2 and the highest maximum power density value of around 574 mW m-2 were obtained for illuminated CNT/TiO2/Chl on the rigid ITO anode. In dark conditions, the highest power density was observed for CNP as the supporting substrate. The photo-bioelectrochemical cell adopting CNT/TiO2/Chl and CNP as the supporting substrate material has great potential for a variety of applications, such as wearable electronics, environmental monitoring, remote or off-grid energy supply, and renewable energy systems, thereby contributing to the advancement of sustainable energy technologies.

Degradation of Phenol in Pharmaceutical Wastewater using TiO2/Pumice and O3/Active Carbon

Phenol is a toxic organic compound that detectable in the pharmaceutical wastewater, and therefore it should be eliminated. This study aims to degrade phenol in the pharmaceutical wastewater treatment using Advanced Oxidation Processes (AOPs) include the photocatalytic process applying Titanium Oxide (TiO2) that immobilized on pumice stone (PS), as well as ozone process with O3 and O3/granulated activated carbon (GAC). Degradation system used two configuration reactors that worked alternately at pH 3 and 9. Photocatalysis was conducted for 4 hours in the photoreactor that equipped with mercury lamp as a photon source, while ozonation was performed for 1 hour in the cylinder glass reactor contained an ozone generator. Phenol degradations were done by photocatalysis, ozonation, photocatalysis followed by ozonation and vice versa. The FESEM-EDS and XRD results depicted that TiO2 has impregnated on pumice stone and FESEM characterization also indicated that the photocatalyst spread across the surface of the pumice stone. BET analysis results in an increased surface area of the PS-TiO2 by 3.7 times, whereas bandgap energy down to 3 eV. It can be concluded that ozone process (with O3/GAC) that followed by photocatalysis at pH 9 could treat the liquid waste with phenol concentration 11.2 down to 1.2 ppm that nearly according to the discharge standards quality (1 ppm). Copyright © 2020 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Optimization of Cellulase Production by Aspergillus niger ITBCC L74 with Bagasse as Substrate using Response Surface Methodology

Cellulase is a very important enzyme for lignocelluloses based ethanol production. Bagasse contains mainly cellulose (57.76%), hemicellulose (12.44%), lignin (21.34%), and others (7.96%). Lignocellulosic material has been considered as the good option for cellulase production because it is cheap and already available in a huge amount. The objective of this research was to produce cellulase enzyme and to optimize it by using response surface methodology. The bagasse with water content of 80% was incubated with 2 ml inoculum of Aspergillus niger ITBCC L74 in a 250 ml Erlenmeyer flask. After reaching the specified time the enzyme was extracted and then determined for its activity. Effect of process parameters such as pH, urea and MgCl2 addition were studied. The optimal cellulase activity was achieved at urea concentration of 4.5% (w/w), MgCl2 concentration of 1 mM and pH of 3.5, with maximum enzyme activity was 0.630 U/gr