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1.
Talanta ; 236: 122838, 2022 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-34635228

RESUMEN

Medium-resolution (MR-NMR) and time-domain NMR relaxometry (TD-NMR) using benchtop and low-field NMR instruments are powerful tools to tackle fuel adulteration issues. In this work, for the first time, we investigate the possibility of enhancing the low-field NMR capability on fuel analysis using data fusion of MR and TD-NMR. We used the ComDim (Common Dimensions Analysis) multi-block analysis to join the data, which allowed exploration, classification, and quantification of common adulterations of diesel fuel by vegetable oils, biodiesel, and diesel of different sources as well as the sulfur content. After data exploration using ComDim, classification (applying linear discriminant analysis, LDA), and regression (applying multiple linear regression, MLR), models were built using ComDim scores as input variables on the LDA and MLR analyses. This approach enabled 100% of accuracy in classifying diesel fuel source (refinery), sulfur content (S10 or S500), vegetable oil, and biodiesel source. Moreover, in the quantification step, all MLR models showed a root mean square error of prediction (RMSEP) and the residual prediction deviation (RPD) values comparable to the literature for determining diesel, vegetable oil, and biodiesel contents.


Asunto(s)
Biocombustibles , Gasolina , Biocombustibles/análisis , Gasolina/análisis , Espectroscopía de Resonancia Magnética , Monitoreo Fisiológico , Aceites Vegetales
2.
J Environ Manage ; 301: 113924, 2022 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-34731947

RESUMEN

The present paper aimed to investigate the roles of quinones contained in wastewater and the enhanced effects on microbial fuel cells (MFCs) under different redox conditions. The feasibility of using wastewater rich in quinones to act as co-substrate and redox mediators (RMs) library to strengthen the synergistic removal of azo dye in MFCs was evaluated. The results demonstrated that quinones achieved enhanced effects on electricity generation and COD removal of MFC better at higher current intensity. The addition of pure quinone decreased electron transfer resistance (Rct) of MFCs from 4.76 Ω to 2.13 Ω under 1000 Ω resistance and 1.16 Ω-0.75 Ω under 50 Ω resistance. Meanwhile, higher coulombic efficiency was achieved. Compared with sodium acetate, using quinone-rich traditional Chinese medicine (TCM) wastewater as the co-substrate enhanced the synergistic removal of reactive red 2 (RR2) in MFCs from 79.58% to 92.45% during 24 h. RR2 was also degraded more thoroughly due to the accelerated electron transfer process mediated by RMs. Microbial community analysis demonstrated that the presence of quinone in TCM wastewater can enrich different exoelectrogens under varied redox conditions and thus influenced the enhanced effects on MFC. Metagenomic functional prediction results further indicated that the abundance of functional genes involved in carbohydrate metabolism, membrane transport metabolism, biofilm formation, and stress tolerance increased significantly in presence of RMs. Redundancy analyses revealed that RMs addition was the more important factor driving the variation of the microorganism community. This study revealed the potential effect of quinones as redox mediators on the bioelectrochemical system for pollutants removal.


Asunto(s)
Fuentes de Energía Bioeléctrica , Compuestos Azo , Electricidad , Electrodos , Oxidación-Reducción , Quinonas , Aguas Residuales
3.
Sci Total Environ ; 802: 149765, 2022 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-34454141

RESUMEN

There is a growing global recognition that microalgae-based biofuel are environment-friendly and economically feasible options because they incur several advantages over traditional fossil fuels. Also, the microalgae can be manipulated for extraction of value-added compounds such as lipids (triacylglycerols), carbohydrates, polyunsaturated fatty acids, proteins, pigments, antioxidants, various antimicrobial compounds, etc. Recently, there is an increasing focus on the co-cultivation practices of microalgae with other microorganisms to enhance biomass and lipid productivity. In a co-cultivation strategy, microalgae grow symbiotically with other heterotrophic microbes such as bacteria, yeast, fungi, and other algae/microalgae. They exchange nutrients and metabolites; this helps to increase the productivity, therefore facilitating the commercialization of microalgal-based fuel. Co-cultivation also facilitates biomass harvesting and waste valorization, thereby help to build an algal biorefinery platform for bioenergy production along with multivariate high value bioproducts and simultaneous waste bioremediation. This article comprehensively reviews various microalgae cultivation practices utilizing co-culture approaches with other algae, fungi, bacteria, and yeast. The review mainly focuses on the impact of several binary culture strategies on biomass and lipid yield. The advantages and challenges associated with the procedure along with their respective cultivation modes have also been presented and discussed in detail.


Asunto(s)
Microalgas , Biodegradación Ambiental , Biocombustibles , Biomasa , Técnicas de Cocultivo
4.
Sci Total Environ ; 802: 149750, 2022 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-34454158

RESUMEN

The continuous growing demand for fossil fuel puts an enormous pressure on finding a better replacement. This research paper explores the detailed information on the improved production, emission and performance characteristics of the distinct bio-oil derived from the micro algae of Schizochytrium. The algae were grown in the artificial seawater with enough nitrogen supply at the required standard conditions. The lipid growth and production of the bio-oil were monitored closely and measured. Different fuel blends were used at different concentrations as B0 (100% Diesel), B10 (10% schizochytrium biofuel +90% diesel), B20 (20% schizochytrium biofuel +80% diesel) and B30 (30% schizochytrium biofuel +70% diesel). A small single cylinder, four stroke diesel engine was used to conduct the tests. All tests were conducted at different speed conditions of 1200 rpm to 2100 rpm in six intervals. The performance qualities of bio-oil such as CO, NOX, and smoke and CO2 emission along with the performance qualities of brake thermal efficiency and brake specific fuel consumption. Form the results, the Schizochytrium microalgae bio-oil as the bio fuel for diesel engines in the moderate level showed the improved performance by increasing the BTE and reducing the harmful gas emissions except NOX. However, the emission level of NOX was slightly higher than the diesel emitted value. The difference between them was negligible.


Asunto(s)
Biocombustibles , Gasolina , Monóxido de Carbono/análisis , Transferencia de Energía , Óxidos de Nitrógeno/análisis , Emisiones de Vehículos
5.
Sci Total Environ ; 802: 149842, 2022 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-34455274

RESUMEN

Global environmental awareness has encouraged further research towards biofuel production and consumption. Despite the favorable properties of biofuels, the sustainability of their conventional production pathways from agricultural feedstocks has been questioned. Therefore, the use of non-food feedstocks as a promising approach to ensure sustainable biofuel production is encouraged. However, the use of synthetic solvents/chemicals and energy carriers during biofuel production and the consequent adverse environmental effects are still challenging. On the other hand, biofuel production is also associated with generating large volumes of waste and wastewater. Accordingly, the circular bioeconomy as an innovative approach to ensure complete valorization of feedstocks and generated waste streams under the biorefinery scheme is proposed. In line with that, the current study aims to assess the environmental sustainability of bioethanol production in a safflower-based biorefinery using the life cycle assessment framework. Based on the obtained results, safflower production and its processing into 1 MJ bioethanol under the safflower-based biorefinery led to damage of 2.23E-07 disability-adjusted life years (DALY), 2.35E-02 potentially disappeared fraction (PDF)*m2*yr, 4.76E-01 kg CO2 eq., and 3.82 MJ primary on the human health, ecosystem quality, climate change, and resources, respectively. Moreover, it was revealed that despite adverse environmental effects associated with safflower production and processing, the substitution of conventional products, i.e., products that are the typical products in the market without having environmental criteria, with their bio-counterparts, i.e., products produced in the biorefinery based on environmental criteria could overshadow the unfavorable effects and substantially enhance the overall sustainability of the biorefinery system. The developed safflower-based biorefinery led to seven- and two-time reduction in damage to the ecosystem quality and resources damage categories, respectively. The reductions in damage to human health and climate change were also found to be 52% and 24%, respectively. The weighted environmental impacts of the safflower-based biorefinery decreased by 64% due to the production of bioproducts, mainly biodiesel and biogas, replacing their fossil-based counterparts, i.e., diesel and natural gas, respectively. Finally, although the main focus of the developed safflower-based biorefinery was biofuel production, waste valorization and mainly animal feed played a significant role in improving the associated environmental impacts.


Asunto(s)
Biocombustibles , Carthamus tinctorius , Animales , Biomasa , Ecosistema , Humanos , Estadios del Ciclo de Vida
6.
Chemosphere ; 286(Pt 1): 131587, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34303047

RESUMEN

Alcohols could be the biggest factor for the improvement of world biofuel economy in the present century due to their excellent properties compared to petroleum products. The primary concerns of sustainable alcohol production for meeting the growing energy demand owing to the selection of viable feedstock and this might enhance the opportunities for developing numerous advanced techniques. In this review, the valorization of alcohol production from several production routes has been exposed by covering the traditional routes to the present state of the art technologies. Even though the fossil fuel conversion could be dominant method for methanol production, many recent innovations like photo electrochemical synthesis and electrolysis methods might play vital role in production of renewable methanol in future. There have been several production routes for production of ethanol and among which the fermentation of lignocellulose biomass would be the ultimate choice for large scale shoot up. The greenhouse gas recovery in the form of alcohols through electrochemistry technique and hydrogenation method are the important methods for commercialization of alcohols in future. It is also observed that algae based renewable bio-alcohols is highly influenced by carbohydrate content and sustainable approaches in algae conversion to bio-alcohols would bring greater demand in future market. There is a lack of innovation in higher alcohols production in single process and this could be bounded by combining dehydrogenation and decarboxylation techniques. Finally, this review enlists the opportunities and challenges of existing alcohols production and recommended the possible routes for making significant enhancement in production.


Asunto(s)
Biocombustibles , Éteres , Biomasa , Etanol , Fermentación
7.
Chemosphere ; 286(Pt 1): 131688, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34346327

RESUMEN

Nowadays, ethanol (ethyl alcohol, bioethanol) is one of the most commonly used liquid biofuels, playing a vital role in industrial development. There are some advanced technologies available to produce ethanol by fermentation of agricultural wastes, fruit wastes, municipal and industrial wastes. Herein, the dried carrot pulp as a source of raw material has been utilized for the production of bioethanol by using the yeast Saccharomyces cerevisiae and beet molasses inoculated at 28 °C for 72 h. The results have revealed that the highest amount of alcohol (10.3 ml (40.63 g/l)) has been obtained in a sample containing 50 ml of inoculum, 150 ml of water, and 10 g of dried waste. This study has proved the potential of dried carrot pulp to be converted into a value-added product such as ethanol.


Asunto(s)
Beta vulgaris , Daucus carota , Biocombustibles , Biomasa , Fermentación , Melaza , Saccharomyces cerevisiae
8.
Chemosphere ; 286(Pt 1): 131618, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34346337

RESUMEN

The main aim of this work was to develop a sustainable Ni/Zeolite catalyst derived from geothermal solid waste for waste cooking oil processing. The effects of catalyst concentration and operation temperature on the transesterification process for biodiesel production which used waste cooking oil as feedstock were investigated to determine the optimum biodiesel process condition. Results have shown the synthesized Ni/Zeolite catalyst was granular in shape and crystalline with increased surface area and pore volume, 80.661 m2 g-1, and 0.123 cc g-1 respectively. Meanwhile, the highest biodiesel yield obtained was 89.4 % at 3 % w/w Ni/Zeolite catalyst addition and 60 °C operating temperature. The reusability of the synthesized catalyst was also investigated, with results showing the biodiesel yield decreasing to 73.3 % after three cycles.


Asunto(s)
Residuos Sólidos , Zeolitas , Biocombustibles , Catálisis , Culinaria , Esterificación , Aceites Vegetales
9.
Chemosphere ; 286(Pt 1): 131619, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34346343

RESUMEN

For wastewater treatment, sediment microbial fuel cells (SMFCs) have advantages over traditional microbial fuel cells in cost (due to their membrane-less structure) and operation (less intensive maintenance). Nevertheless, the technical obstacles of SMFCs include their high internal electrical resistance due to sediment in the anode chamber and slow oxygen reduction reaction (ORR) in the cathode chamber, which is responsible for their low power density (PD) (0.2-50 mW/m2). This study evaluated several SMFC improvements, including anode and cathode chamber amendment, electrode selection, and scaling the chamber size up to obtain optimally constructed single-chamber SMFCs to treat fat, oil, and grease (FOG) trap effluent. The chemical oxygen demand (COD) removal efficiency, PD, and electrical energy conversion efficiency concerning theoretically available chemical energy from FOG trap effluent treatment (%ECWW) were examined. Packing biochar in the anode chamber reduced its electrical resistance by 5.76 times, but the improvement in PD was trivial. Substantial improvement occurred when packing the cathode chamber with activated carbon (AC), which presumably catalyzed the ORR, yielding a maximum PD of 109.39 mW/m2, 959 times greater than without AC in the cathode chamber. This SMFC configuration resulted in a COD removal efficiency of 85.80 % and a %ECWW of 99.74 % in 30 days. Furthermore, using the most appropriate electrode pair and chamber volume increased the maximum PD to 1787.26 mW/m2, around 1.7 times greater than the maximum PD by SMFCs reported thus far. This optimally constructed SMFC is low cost and applicable for household wastewater treatment.


Asunto(s)
Fuentes de Energía Bioeléctrica , Purificación del Agua , Electricidad , Electrodos , Hidrocarburos
10.
Chemosphere ; 286(Pt 1): 131623, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34346348

RESUMEN

The increasing demand for the development of sustainable strategies to utilize and process agro-industrial residues paves new paths for exploring innovative approaches in this area. Biotechnology based microbial transformations provide efficient, low cost and sustainable approaches for the production of value added products. The use of organic rich residues opens new avenues for the production of enzymes, pigments, biofuels, bioactive compounds, biopolymers etc. with vast industrial and therapeutic applications. Innovative technologies like strain improvement, enzyme immobilization, genome editing, morphological engineering, ultrasound/supercritical fluid/pulse electric field extraction, etc. can be employed. These will be helpful in achieving significant improvement in qualitative and quantitative parameters of the finished products. The global trend for the valorisation of biowaste has boosted the commercialization of these products which has transformed the markets by providing new investment opportunities. The upstream processing of raw materials using microbes poses a limitation in terms of product development and recovery which can be overcome by modifying the bioreactor design, physiological parameters or employing alternate technologies which will be discussed in this review. The other problems related to the processes include product stability, industrial applicability and cost competitiveness which needs to be addressed. This review comprehensively discusses the recent progress, avenues and challenges in the approaches aimed at valorisation of agro-industrial wastes along with possible opportunities in the bioeconomy.


Asunto(s)
Biocombustibles , Residuos Industriales , Reactores Biológicos , Biotecnología , Industrias
11.
Sci Total Environ ; 802: 149989, 2022 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-34525720

RESUMEN

Microbial fuel cells (MFCs) are promising equipment for water treatment and power generation. The catalyst used in the oxygen reduction reaction (ORR) at the cathode is a critical factor for efficacy of MFCs. Therefore, it is important to develop cost-effective cathode catalysts to enhance application of MFCs. In the current study, a novel cathode catalyst was developed, which was annealed with watermelon rind as raw material and transition metals including iron, and manganese were introduced. The 700Mn/Fe@WRC catalyst, which was annealed at 700 °C, exhibited excellent electrochemical performance. The high relative content of pyridine nitrogen caused by the inherent nitrogen element of the watermelon rind and the high content of iron and manganese elements introduced resulted in increase in electrochemical surface area to 657.6 m2/g. The number of electrons transferred ORR was 3.96, indicating that ORR occurs through a four-electron pathway. The maximum power density of MFCs was 399.3 ± 7.4 mW/m2 with a fitting total internal resistance of 15.242 Ω, and the removal efficiency of COD was 97.1 ± 1.2%. The cost of the 700Mn/Fe@WRC catalyst was approximately 0.15 $/g, which is significantly lower compared with Pt/C (33.0 $/g). Experimental verification showed that the 700Mn/Fe@WRC prepared using the economical watermelon rind biochar (WRC) is an excellent substitute for non-precious metal catalysts used in MFCs.


Asunto(s)
Fuentes de Energía Bioeléctrica , Citrullus , Catálisis , Carbón Orgánico , Electrodos , Manganeso , Oxígeno
12.
Sci Total Environ ; 802: 149863, 2022 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-34525749

RESUMEN

The depletion of fuel production and raising ecological issues have paid the progress of biofuels in the entire world. Among different biofuels is introducing renewable fuel additives as prospective beneficial blendstocks towards fulfilling systematic, low-carbon technologies internal combustion engines. This research article proposes a new approach to formulate a Fuzzy modeling for examining various promising alternative renewable oxygenated compounds, including ethanol, isopropanol, MTBE, and 2-methyl furan into heavy hydrocracked gasoline a base fuel. No previous study has utilized Fuzzy modeling in formulation of producing high octane fuel based on renewable additives compounds. The effect of selected additives was investigated on the antiknock characteristics. The results reported that the quality and quantity of heavy hydrocracked naphtha have been reinforced, using low carbon oxygenates. Besides, the acquired results provided the possibility to determine the optimum range of selected renewable oxygenates percentages of 30-50% wt. The calculated data of Fuzzy modeling were verified with experimental results. It illustrated that predicted environmental gasoline yields agreed well with experimental results. Finally, low carbon liquid fuel could contribute to produce high quality environmental gasoline, improve environmental characteristics, in terms of decreasing greenhouses emissions, and maximize the vehicles technologies.


Asunto(s)
Gasolina , Petróleo , Biocombustibles , Octanos , Estudios Prospectivos , Emisiones de Vehículos
13.
Chemosphere ; 287(Pt 2): 132165, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34826901

RESUMEN

High energy consumption and depletion of fossil fuels lead to the introduction of new technologies to produce alternative fuels with fewer emissions of greenhouse gases. The present investigation was focused to utilize the waste coal washery rejects as a substrate to produce biogenic methane under optimum conditions. Experiments were performed to explore the efficiency of non-coal samples (cow dung, distillery anaerobic digester sludge) and coal mines enriched samples in the degradation of coal washery rejects. Further cow dung, distillery anaerobic sludge, and coal washery rejects were taken at various concentrations to develop anaerobic slurry and analysed for its biogas production. The anaerobic slurry which contains 1:1:1 of cow dung, distillery anaerobic sludge, and coal washery rejects produced methane of around 55.7%. The coal enriched samples showed a maximum of 22.6% of methane. Subsequently, the best methane-producing anaerobic non-coal consortiums were compared with coal enriched microbial culture in converting coal washery rejects of 10 g/l to methane. Results revealed that cow dung inoculum and coal mine enriched inoculum source produced the nearly same amount of methane. This study suggested that the selected anaerobic slurries and coal enriched samples can utilize sub-bituminous coal washery rejects in methane production. Thus, these consortiums can be applied in converting a large amount of coal washery rejects into methane thus can lead to the reclamation of the site.


Asunto(s)
Carbón Mineral , Metano , Biocombustibles , Aguas del Alcantarillado
14.
Chemosphere ; 287(Pt 2): 132247, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34826930

RESUMEN

Chemical park is regarded as a major contributor of VOCs emissions in China. Currently, a green and safe technology, microbial fuel cells (MFCs), is being developed for the VOCs abatement. Noting that effective electron transfer is critical to the MFC performance. In this work, flavin mononucleotide (FMN) was dosed as an electron shuttle to improve the removal of the typical toxic VOCs, toluene. The experimental results revealed that the performance of toluene removal and power generation were accelerated with the dosage of 0.2-2 µM FMN. With the addition of 1 µM FMN, the removal efficiency, the maximum output voltage and the coulombic efficiency of MFC were increased by 18.4%, 64.4% and 56.3%, respectively. However, a further increase in FMN concentration to 2 µM caused a reduction in the removal efficiency and coulombic efficiency. The images of scanning electron microscopy and confocal laser scanning microscopy showed that the presence of FMN greatly promoted the microbial growth and its activity. Furthermore, microbial community analysis also implied that the moderate dosage of FMN (0.2-1 µM) was beneficial for the growth of the typical exoelectrogens, Geobacter sp., and thus the coulombic efficiency was increased. In addition, an electron transfer pathway involving in cytochrome b, OMCs, cytochrome c, and MtrA was proposed based on the cyclic voltammetry analysis. This work will provide a fundamental theoretical support for its application of toxic VOCs abatement from the chemical park.


Asunto(s)
Fuentes de Energía Bioeléctrica , Electrodos , Mononucleótido de Flavina , Gases , Tolueno
15.
Chemosphere ; 287(Pt 3): 132277, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34826938

RESUMEN

Microbial fuel cells (MFCs) are sensitive to acidity variations in both bioelectricity generation and biochemical digestion aspects, therefore online pH monitoring is of necessity to guarantee optimal function of MFCs. Present pH meters hardly fulfill this special need. In this work, we designed a novel voltammetric pH sensor based on electrochemically reduced graphene oxide (rGO) modified screen printed electrode. By surface doping of alizarin, good linearity of pH sensing over the range of 4.0-9.0 can be realized. Fast readout can be acquired within 15 s for each test. pH monitoring for artificial wastewater with inoculum of granular activated sludge in a MFC was successfully illustrated. Specially, it was verified that the performance was improved with alizarin doping due to the enhanced rGO surface proton diffusion. This approach provides an online, calibration-free and long stable pH monitoring method for the future MFC development.


Asunto(s)
Fuentes de Energía Bioeléctrica , Grafito , Nanocompuestos , Antraquinonas , Electrodos , Concentración de Iones de Hidrógeno
16.
Sci Total Environ ; 806(Pt 1): 150220, 2022 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-34560453

RESUMEN

Using microbial fuel cells with constructed wetlands (MFC-CWs) for eliminating antibiotics has recently attracted extensive attention. However, antibiotic removal efficiencies in MFC-CWs must be enhanced, and the accumulation of antibiotic resistant genes (ARGs) remains an unmanageable issue. This study tries to enhance the antibiotic removal in synthetic wastewater and reduce ARGs by adding sponge iron (s-Fe0) and calcium peroxide to the anode and cathode of MFC-CWs, respectively, and/or simultaneously. The results demonstrated that adding s-Fe0 and calcium peroxide to MFC-CWs could improve the removal efficiencies of sulfamethoxazole (SMX) and tetracycline (TC) by 0.8-1.3% and 6.0-8.7%. Therein, s-Fe0 also significantly reduced 84.10-94.11% and 49.61-60.63% of total sul and tet genes, respectively. Furthermore, s-Fe0 improved the voltage output, power density, columbic efficiency, and reduced the internal resistance of reactors. The intensification to the electrode layers posed a significant effect on the microbial community composition and functions, which motivated the shift of antibiotic removal, accumulation of ARGs and bioelectricity generation in MFC-CWs. Given the overall performance of MFC-CWs, adding s-Fe0 to the anode region of MFC-CWs was found to be an effective strategy for removing antibiotics and reducing the accumulation of ARGs.


Asunto(s)
Fuentes de Energía Bioeléctrica , Humedales , Antibacterianos , Electrodos , Hierro , Aguas Residuales/análisis
17.
Chemosphere ; 287(Pt 4): 132383, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34592205

RESUMEN

Treatment wetlands (TW) operated as bioelectrochemical systems (BES-TW) provide a higher degree of treatment than conventional TW. Yet, the fundamental processes or mechanisms for the envisaged better performance of BES-TW over conventional TW remains poorly understood. This work aimed to determine to which extent microbial activity enhancement could be the reason behind this treatment performance increase. To this purpose, pilot-scale horizontal sub-surface flow BES-TW operated under three different configurations were continuously fed with real urban wastewater. BES-TW were evaluated for COD and ammonia removal efficiency, and two techniques of microbial activity assessment were applied. Configurations, tested in duplicate, were: control TWs without electrodes (C-TW), TWs operated as microbial fuel cells (MFC-TW), and TWs operated as microbial electrolysis cells (MEC-TW). Microbial activity was assessed by measuring the enzymatic activity (EA) (FDA hydrolysis technique) and the aerobic activity (AA) (estimated through respirometry). Results showed that BES-TW outperformed C-TW in terms of both microbial activity enhancement and contaminants removal efficiency, especially in the case of MEC-TW. More precisely, this configuration showed an average improvement of 17%, and 56% in COD removal and EA efficiencies, respectively, compared to C-TW. Regarding AA activity, although MEC-TW seemed to outperform the rest of the configurations, differences were not statistically significant. This work demonstrates that TWs operated as BES increase the overall enzymatic activity of the treatment bed and this, in turn, is the leading cause to a higher degree of treatment performance.


Asunto(s)
Fuentes de Energía Bioeléctrica , Humedales , Electrodos , Electrólisis , Aguas Residuales/análisis
18.
Chemosphere ; 287(Pt 4): 132384, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34597645

RESUMEN

BiFeO3 nanoparticle decorated on flower-like ZnO (BiFeO3/ZnO) was fabricated through a facile hydrothermal-reflux combined method. This material was utilized as a composite photocathode for the first time in microbial fuel cell (MFC) to reduce the copper ion (Cu2+) and power generation concomitantly. The resultant BiFeO3/ZnO-based MFC displayed distinct photoelectrocatalytic activities when different weight percentages (wt%) BiFeO3 were used. The 3 wt% BiFeO3/ZnO MFC achieved the maximum power density of 1.301 W m-2 in the catholyte contained 200 mg L-1 of Cu2+ and the power density was greatly higher than those pure ZnO and pure BiFeO3 photocathodes. Meanwhile, the MFC exhibited 90.7% removal of Cu2+ within 6 h under sunlight exposure at catholyte pH 4. The addition of BiFeO3 nanoparticles not only manifested outstanding capability in harvesting visible light, but also facilitated the formation of Z-scheme BiFeO3/ZnO heterojunction structure to induce the charge carrier transfer along with enhanced redox abilities for the cathodic reduction. The pronounced electrical output and Cu2+ reduction efficiencies can be realized through the synergistic cooperation between the bioanode and BiFeO3/ZnO photocathode in the MFC. Furthermore, the developed BiFeO3/ZnO composite presented a good stability and reusability of photoelectrocatalytic activity up to five cyclic runs.


Asunto(s)
Fuentes de Energía Bioeléctrica , Óxido de Zinc , Cobre , Electricidad , Electrodos
19.
Chemosphere ; 287(Pt 4): 132439, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34606889

RESUMEN

The rising global population and their food habits result in food wastage and cause an obstacle in its treatment and disposal. Due to the rapid shift in the lifestyle of the human population and urbanization, almost one-third of the food produced is wasted from various sectors like domestic sources, agricultural sectors, and industrial sectors. These food resources squandered are rich in organic biomolecules which can cause complications upon direct disposal in the environment. Conventional disposal methods like composting, landfills and incineration demand high costs besides causing severe environmental and health issues. To overcome these demerits of the conventional methods and to avoid the loss of rich organic food resources, there is an immediate need for a sustainable and eco-friendly solution for the valorization of the food wastes. Microbial fuel cells (MFCs) are gaining attention, due to their ideal approach in the production of electricity and parallel treatment of organic food wastes. The MFCs are significant as an innovative approach using microorganisms and oxidizing the organic food wastes into bio-electricity. In this review, the recent advancements and practices of the MFCs in the field of food waste treatment and management along with electricity production are discussed. The major outcome of this work highlights the setting up of MFC for the treatment of higher volumes of food waste residues and enhancing the bioelectricity production in an optimal condition. For further improvements in the food waste treatments using MFCs, greater understanding and more research needs are to be focused on the commercialization, different operational modes, operational types, and low-cost fabrication coupled with careful examination of scale-up factors.


Asunto(s)
Fuentes de Energía Bioeléctrica , Eliminación de Residuos , Electricidad , Electrodos , Alimentos , Humanos , Incineración
20.
Chemosphere ; 287(Pt 4): 132299, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34627010

RESUMEN

Anaerobic digestion (AD) serves as a potential bioconversion process to treat various organic wastes/wastewaters, including sewage sludge, and generate renewable green energy. Despite its efficiency, AD has several limitations that need to be overcome to achieve maximum energy recovery from organic materials while regulating inhibitory substances. Hence, bioelectrochemical systems (BESs) have been widely investigated to treat inhibitory compounds including ammonia in AD processes and improve the AD operational efficiency, stability, and economic viability with various integrations. The BES operations as a pretreatment process, inside AD or after the AD process aids in the upgradation of biogas (CO2 to methane) and residual volatile fatty acids (VFAs) to valuable chemicals and fuels (alcohols) and even directly to electricity generation. This review presents a comprehensive summary of BES technologies and operations for overcoming the limitations of AD in lab-scale applications and suggests upscaling and future opportunities for BES-AD systems.


Asunto(s)
Reactores Biológicos , Aguas del Alcantarillado , Anaerobiosis , Biocombustibles , Metano
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