Bioelectricity generation using long-term operated biocathode: RFLP based microbial diversity analysis

FRH/BPD/33864/2009 UIDB/50006/2020 UIDP/50006/2020In the present work, power generation and substrate removal efficiencies of long-term operated microbial fuel cells, containing abiotic cathodes and biocathodes, were evaluated for 220 days. Among the two microbial fuel cell (MFC) types, the one containing biocathode showed higher power density (54 mW/m2), current density (122 mA/m2) coulombic efficiency (33%), and substrate removal efficiency (94%) than the abiotic cathode containing MFC. Voltammetric analysis also witnessed higher and sustainable electron discharge for the MFC with biocathode, when compared with the abiotic cathode MFC. Over the tested period, both MFC have shown a cell voltage drop, after 150 and 165, days, for the MFC with biocathode and abiotic cathodes, respectively. Polymerase chain reaction (PCR) based restriction fragment length polymorphism (RFLP) analysis identified 281 clones. Bacteria belonging to Acinetobacter, Acidovorax, Pseudomonas and Burkholderia were observed in the abiotic cathode MFC. Bacteria belonging to Geobacter, Cupriavidus and Acidobacteria were observed in the biocathode MFC. Almost similar types of archaea (Methanosarcinales, Methanolinea, Nitrososphaera and Methanomicrobiales) were observed in both MFCs.publishersversionpublishe

Review of the Developments of Bacterial Medium-Chain-Length Polyhydroxyalkanoates (mcl-PHAs)

Synthetic plastics derived from fossil fuels—such as polyethylene, polypropylene, polyvinyl chloride, and polystyrene—are non-degradable. A large amount of plastic waste enters landfills and pollutes the environment. Hence, there is an urgent need to produce biodegradable plastics such as polyhydroxyalkanoates (PHAs). PHAs have garnered increasing interest as replaceable materials to conventional plastics due to their broad applicability in various purposes such as food packaging, agriculture, tissue-engineering scaffolds, and drug delivery. Based on the chain length of 3-hydroxyalkanoate repeat units, there are three types PHAs, i.e., short-chain-length (scl-PHAs, 4 to 5 carbon atoms), medium-chain-length (mcl-PHAs, 6 to 14 carbon atoms), and long-chain-length (lcl-PHAs, more than 14 carbon atoms). Previous reviews discussed the recent developments in scl-PHAs, but there are limited reviews specifically focused on the developments of mcl-PHAs. Hence, this review focused on the mcl-PHA production, using various carbon (organic/inorganic) sources and at different operation modes (continuous, batch, fed-batch, and high-cell density). This review also focused on recent developments on extraction methods of mcl-PHAs (solvent, non-solvent, enzymatic, ultrasound); physical/thermal properties (Mw, Mn, PDI, Tm, Tg, and crystallinity); applications in various fields; and their production at pilot and industrial scales in Asia, Europe, North America, and South America

Thermal Analysis on Kerosene Oil-Based Two Groups of Ternary Hybrid Nanoparticles (CNT-Gr-Fe3O4 and MgO-Cu-Au) Mix Flow over a Bidirectional Stretching Sheet: A Comparative Approach

The present work examines the impressions of radiation impact on the three-dimensional non-Newtonian MHD Casson flow of ternary hybrid nanofluids over a symmetrical stretching sheet with magnetic impression and heat generation/absorption. The unique boost in thermal efficiency and development of the rate of heat transport as valid to the dynamics of energy and coolant in automobiles is what has led to an increase in knowledge of hybrid nanofluid. For the study, two groups of ternary nanoparticles (CNT-Gr-Fe3O4 and MgO-Cu-Au) are combined with the base fluid kerosene oil. A nonlinear partial differential equation system is created while keeping in mind some reasonable presumptions. Using the similarities transformation, PDE’s are changed into nonlinear ODE’s. Also, it is then mathematically simplified with the bvp4c technique. The consequences of an exclusive group of unique impacts on motion characteristics, skin friction coefficient, thermal field impressions, heat transport rate, concentration distribution, and mass transfer rate are described clearly. The motion in the x and y directions decays with increasing the Casson fluid parameter 0.04≤β≤0.06 and magnetic impact 6≤M≤10 for ternary groups I and II. An energy upsurge profile appears for radiation impression (1 ≤ Nr ≤ 20) and heat source/sink (0.1 ≤ Q ≤ 1.5). When compared to rising Dufour number (0.1 ≤ Du ≤ 0.9) and heat source/sink values (0.1 ≤ Q ≤ 1.5), the Nusselt number decreases. The volume fraction 0.1≤ϕ≤0.3 of ternary nanoparticles rises the velocity (in both directions) and thermal distributions. Also, the Nusselt number enhances for both ternary groups when increasing thermal radiation (1 ≤ Nr ≤ 20)