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1.
J Environ Manage ; 363: 121434, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38861886

RESUMO

Despite benefits such as lower water and working volume requirements, thermophilic high solids anaerobic digestion (THSAD) often fails due to the rapid build-up of volatile fatty acids (VFAs) and the associated drop in pH. Use of conductive materials (CM) can promote THSAD through stimulation of direct interspecies electron transfer (DIET), while the need for their constant dosing due to poor separation from effluent impairs economic feasibility. This study used an approach of spatially separating magnetite and granular activated carbon (GAC) from the organic fraction of municipal solid waste (OFMSW) in a single reactor for THSAD. GAC and magnetite addition could both mitigate the severe inhibition of methanogenesis after VFAs build-up to ∼28-30 g/L, while negligible methane production was observed in the control group. The highest methane yield (286 mL CH4/g volatile solids (VS)) was achieved in magnetite-added reactors, while the highest maximum CH4 production rates (26.38 mL CH4/g VS/d) and lowest lag-phase (2.83 days) were obtained in GAC-added reactors. The enrichment of GAC and magnetite biofilms with various syntrophic and potentially electroactive microbial groups (Ruminiclostridium 1, Clostridia MBA03, Defluviitoga, Lentimicrobiaceae) in different relative abundances indicates the existence of specific preferences of these groups for the nature of CM. According to predicted basic metabolic functions, CM can enhance cellular processes and signals, lipid transport and metabolism, and methane metabolism, resulting in improved methane production. Rearrangement of metabolic pathways, formation of pili-like structures, enrichment of biofilms with electroactive groups and a significant improvement in THSAD performance was attributed to the enhancement of the DIET pathway. Promising results obtained in this work due to the spatial separation of the bulk OFMSW and CM can be useful for modeling larger-scale THSAD systems with better recovery of CM and cost-effectiveness.


Assuntos
Reatores Biológicos , Metano , Resíduos Sólidos , Anaerobiose , Metano/metabolismo , Ácidos Graxos Voláteis/metabolismo , Eliminação de Resíduos/métodos , Óxido Ferroso-Férrico/química
2.
Environ Res ; 256: 119218, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-38782335

RESUMO

The production of chemicals/products so far relies on fossil-based resources with the creation of several environmental problems at the global level. In this situation, a sustainable and circular economy model is necessitated to mitigate global environmental issues. Production of biowaste from various processing industries also creates environmental issues which would be valorized for the production of industrially important reactive and bioactive compounds. Lignin acts as a vital part in biowaste composition which can be converted into a wide range of phenolic compounds. The phenolic compounds have attracted much attention, owing to their influence on diverse not only organoleptic parameters, such as taste or color, but also active agents for active packaging systems. Crop residues of varied groups, which are an affluent source of lignocellulosic biomass could serve as a renewable resource for the biosynthesis of ferulic acid (FA). FA is obtained by the FA esterase enzyme action, and it can be further converted into various tail end phenolic flavor green compounds like vanillin, vanillic acid and hydroxycinnamic acid. Lignin being renewable in nature, processing and management of biowastes towards sustainability is the need as far as the global industrial point is concerned. This review explores all the approaches for conversion of lignin into value-added phenolic compounds that could be included to packaging applications. These valorized products can exhibit the antioxidant, antimicrobial, cardioprotective, anti-inflammatory and anticancer properties, and due to these features can emerge to incorporate them into production of functional foods and be utilization of them at active food packaging application. These approaches would be an important step for utilization of the recovered bioactive compounds at the nutraceutical and food industrial sectors.


Assuntos
Lignina , Fenóis , Lignina/química , Fenóis/química , Fenóis/análise , Hidrolases de Éster Carboxílico/metabolismo , Ácidos Cumáricos/química , Resíduos Industriais
3.
Biotechnol Biofuels Bioprod ; 17(1): 72, 2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38811976

RESUMO

Succinic acid (SA) is one of the top platform chemicals with huge applications in diverse sectors. The presence of two carboxylic acid groups on the terminal carbon atoms makes SA a highly functional molecule that can be derivatized into a wide range of products. The biological route for SA production is a cleaner, greener, and promising technological option with huge potential to sequester the potent greenhouse gas, carbon dioxide. The recycling of renewable carbon of biomass (an indirect form of CO2), along with fixing CO2 in the form of SA, offers a carbon-negative SA manufacturing route to reduce atmospheric CO2 load. These attractive attributes compel a paradigm shift from fossil-based to microbial SA manufacturing, as evidenced by several commercial-scale bio-SA production in the last decade. The current review article scrutinizes the existing knowledge and covers SA production by the most efficient SA producers, including several bacteria and yeast strains. The review starts with the biochemistry of the major pathways accumulating SA as an end product. It discusses the SA production from a variety of pure and crude renewable sources by native as well as engineered strains with details of pathway/metabolic, evolutionary, and process engineering approaches for enhancing TYP (titer, yield, and productivity) metrics. The review is then extended to recent progress on separation technologies to recover SA from fermentation broth. Thereafter, SA derivatization opportunities via chemo-catalysis are discussed for various high-value products, which are only a few steps away. The last two sections are devoted to the current scenario of industrial production of bio-SA and associated challenges, along with the author's perspective.

4.
Sci Rep ; 14(1): 9222, 2024 04 22.
Artigo em Inglês | MEDLINE | ID: mdl-38649433

RESUMO

Microwave (MW) heating has gained significant attention in food industries and biomass-to-biofuels through pyrolysis over conventional heating. However, constraints for promoting MW heating related to the use of different MW absorbers are still a major concern that needs to be investigated. The present study was conducted to explore the MW heating performance of biochar as a low-cost MW absorber for performing pyrolysis. Experiments were performed on biochar under different biochar dosing (25 g, 37.5 g, 50 g), MW power (400 W, 700 W, 1000 W), and particle sizes (6 mm, 8 mm, 10 mm). Results showed that MW power and biochar dosing significantly impacted average heating rate (AHR) from 17.5 to 65.4 °C/min at 400 W and 1000 W at 50 g. AHR first increased, and then no significant changes were obtained, from 37.5 to 50 g. AHR was examined by full factorial design, with 94.6% fitting actual data with predicted data. The model suggested that the particle size of biochar influenced less on AHR. Furthermore, microwave absorption efficiency and biochar weight loss were investigated, and microwave absorption efficiency decreased as MW power increased, which means 17.16% of microwave absorption efficiency was achieved at 400 W rather than 700 W and 1000 W. Biochar weight loss estimated by employing mass-balance analysis, 2-10.4% change in biochar weight loss was obtained owing to higher heating rates at higher powers and biochar dosing.


Assuntos
Carvão Vegetal , Micro-Ondas , Pirólise , Carvão Vegetal/química , Calefação , Tamanho da Partícula , Temperatura Alta
5.
Sci Total Environ ; 930: 172649, 2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-38649042

RESUMO

Food, energy, and water resources are intricately interconnected, and nexus provides a holistic approach for addressing these complex links to minimize inefficiencies and waste. Nexus approach and circular economy are considered as effective solutions for sustainability. Quantification of these relations is the first step towards incorporating nexus modeling which helps sustainable production and consumption. For achieving the Sustainable Development Goals, understanding and effectively managing the FEW nexus becomes imperative. With an integral performance perspective, there is a need to address the interdependencies and trade-offs among food, energy, and water systems and challenges of economic, social and environmental sustainability. The aim of this study is to provide a comprehensive analysis of the FEW nexus, identify key opportunities and challenges, and propose integrated strategies for managing these core environmental verticals sustainably. The study addresses the accomplishment of these goals through nexus approaches and outlines the need for technological advancements for shared benefits among resources, contributing to conceptual development of nexus and circular economy. The results highlight the critical importance of adopting a nexus approach to advance sustainable development goals, enhance resource efficiency, and promote synergistic solutions across food, energy, and water systems.

6.
J Environ Manage ; 345: 118907, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37666133

RESUMO

The semi-continuous anaerobic co-digestion (AcoD) of thermal and thermal-alkali pretreated organic fraction of municipal solid waste (OFMSW) and sewage sludge (SS) was studied under varying hydraulic retention times (HRT) and organic loading rates (OLR Three semi-continuous digesters were operated under control (non-pre-treated), thermally pretreated (125 °C), and thermal-alkali pretreated (125°C-3g/L NaOH) conditions at variable OLRs at 2.5, 4.0, 5.1, and 7.6 kgVS/m3.d and corresponding HRTs of 30, 20, 15, and 10 days. The 10 and 43% higher methane yield (0.445 m3/kgVS) and 11 and 57% higher VS removal (52%) was achieved for thermal-alkali pretreated digester at 5.1 kgVS/m3.d OLR over thermally pretreated (0.408 m3/kgVS, 45% VS removal) and control digesters (0.310 m3/kgVS, 33% VS removal), respectively. Thermal and thermal-alkali digesters failed on increasing the OLR to 7.6 kgVS/m3.d, whereas the control digester becomes upset at 5.1 kgVS/m3.d OLR. The metagenomic study revealed that Firmicutes, Bacteroidetes, Chloroflexi, Euryarchaeota, Proteobacteria, and Actinobacteria were the predominant bacterial population, whereas Methanosarcina and Methanothrix dominated the archaeal community. Energy balance analysis revealed that thermal alkali pretreatment showed the highest positive energy balance of 114.6 MJ/ton with an energy ratio of 1.25 compared with thermally pretreated (81.5 MJ/ton) and control samples (-46.9 MJ/ton). This work pave the way for scaleup of both thermal and thermal-alkali pre-treatment at 125 °C to realize the techno-economic and energy potential of the process.


Assuntos
Microbiota , Resíduos Sólidos , Anaerobiose , Álcalis , Metano , Digestão
7.
Artigo em Inglês | MEDLINE | ID: mdl-37667121

RESUMO

Fungal pre-treatment using Pleurotus ostreatus (PO) was carried out on individual and combinations of agro-waste wheat straw (WS), rice straw (RS), and pearl millet straw (PMS) with the addition of biochar (5%,7.5% and 10%) to reduce the pre-treatment duration. Further remaining substrate known as spent mushroom substrate (SMS) was used in anaerobic digestor (AD) for estimation enhanced biomethane yield. Equal ratios of RS + WS, WS + PMS, PMS + RS, and RS + PMS + WS and biochar addition were taken for enhancing pre-treatment, PO growth and AD process. The extent of pre-treatment was recorded with the maximum lignin removal of 40.4% for RS + PMS + WS as compared to untreated counterparts and 0.5%, 2.2%, and 3.3% times more lignin removal from individual PMS, RS, and WS respectively. Addition of biochar to the substrates reduced the total pre-treatment duration by days as compared to the non-biochar substrates. Biological efficiency (BE) used for the analysis of mushroom growth varied from 51-92%. Further, the average bio-methane yield was 187 ml/gVS for SMS of PMS + WS + RS with 10% biochar indicating an increment of 83.33% from untreated SMS of PMS + WS + RS. This, higher biomethane yield was 9.35%, 22.22% and 57.14% times higher than individual SMS of PMS, RS, and WS respectively. The current study shows that biochar not only enhances the bio-methane yield but also reduces the biological pre-treatment duration and removes the dependency on one lignocellulosic biomass for energy (bio-methane) and food (mushroom) production.

8.
J Environ Manage ; 344: 118684, 2023 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-37536236

RESUMO

The disinfection efficacy of standalone chlorine, UV and their combined approach (hybrid) was investigated for the coliform removal in BioKube 1 and 2 treated effluents collected from different environmental settings of clinical and domestic wastes. Chlorine and UV disinfection were applied to BioKube treated wastewater with doses from 0 to 4 mg L-1 and 0-166 mJ cm-2 respectively. Combined disinfection strategies were designed to reduce the dose of chlorine and UV and to exploit the synergistic effect of them. The culturable coliforms were enumerated in treated wastewater sample (control), immediately after (reduction), and 24 h post disinfections (regrowth) using culture media plating and colilert-18 media. Both the BioKube systems (1 and 2) were effective in achieving the strict norms of physicochemical parameters, but not following the coliform counts of treated effluent for reuse in irrigation. A hybrid strategy of chlorine followed by UV was found to be the most effective among various standalone and combination approaches for the removal of coliforms (>4 log ER or <1000 CFU/100 mL) from both the treated effluents. However, coliform present in treated effluent of BioKube 1 were resisting (regrowth) against all kind of applied disinfectants except chlorine followed by UV dose at or more than 0.5 mg L-1 + 41 mJ cm-2. Limited reports are available on hybrid disinfection approaches with decentralized packaged sewage treatment units and this study would help to adopt as an effective tertiary treatment strategy for reuse of treated sewage for irrigation while ensuring public health safety.


Assuntos
Desinfecção , Purificação da Água , Esgotos , Águas Residuárias , Cloro , Laboratórios Clínicos , Comportamento de Redução do Risco , Raios Ultravioleta
9.
J Environ Manage ; 343: 118219, 2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-37229852

RESUMO

The exponential generation of municipal solid waste (MSW) and landfill disposal without any treatment has increased the continuous generation of landfill leachate. Improper MSW and leachate management are contributing to environmental degradation and water and soil pollution, which must be treated. Numerous works have been conducted on leachate treatments for energy and resource recovery. This review presents a comprehensive study of leachate management in which different treatment methods are discussed to analyze the suitability of processes that can be employed to treat leachate efficiently. Further, the characteristics of leachate are examined as properties of leachate may be varied depending upon the region. Still, several challenges related to leachate management and its treatments are discussed in this study. An integrated system could be a better option for treating leachate because it contains large amounts of organic and inorganic compounds. Proper leachate management would help to recover energy and value-added products (metals).


Assuntos
Eliminação de Resíduos , Poluentes Químicos da Água , Resíduos Sólidos/análise , Instalações de Eliminação de Resíduos , Poluentes Químicos da Água/análise , Água , Eliminação de Resíduos/métodos
10.
J Environ Manage ; 341: 118124, 2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37172349

RESUMO

Currently, the phenomenon of direct interspecies electron transfer (DIET) is of great interest in the technology of anaerobic digestion (AD) due to potential performance benefits. However, the conditions for the occurrence of DIET and its limits on improving AD under conditions close to real have not been studied enough. This research is concentrated on the effect of conductive carbon cloth (R3), in comparison with a dielectric fiberglass cloth (R2) and control (R1), on the AD performance in large (90 L) thermophilic reactors, fed with a mixture of simulated organic fraction of municipal solid waste and sewage sludge. While organic loading rate (OLR) was gradually increased from 2.4 to 8.66 kg VS/(m3 day), a statistically significant (p < 0.05) difference in biogas production was observed between R1 and both R2 and R3. However, at a maximum OLR of 12.12 kg VS/(m3 day) in R3, an increase in biogas production (p < 0.05) was observed both compared to R1 (by 8.97%) and R2 (by 4.24%). The content of volatile fatty acids in R3 as a whole was the lowest, especially at the maximum OLR. Biofilm on carbon cloth was rich in syntrophic microorganisms of the genera Tepidanaerobacter, as well as Defluviitoga, capable of DIET in mixed cultures with Methanothrix, which was the most abundant methanogen in biofilm. Suspended Bifidobacterium, Fervidobacterium and Anaerobaculum were negatively affected, while Defluviitoga, Methanothermobacter and Methanosarcina, on the contrary, were positively affected by the increase in OLR and showed, respectively, a negative and positive correlation (p < 0.05) with the main AD performance parameters.


Assuntos
Carbono , Microbiota , Anaerobiose , Biocombustíveis , Bactérias , Esgotos , Reatores Biológicos/microbiologia , Metano
11.
Bioresour Technol ; 376: 128919, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36934902

RESUMO

The performance and kinetics response of thermophilic semi-continuous dark fermentation (DF) of simulated complex carbohydrate-rich waste was investigated at various hydraulic retention times (HRT) (2, 2.5, and 3 d) and compared with data obtained from biochemical hydrogen potential assay (BHP). A culture of Thermoanaerobacterium thermosaccharolyticum was used as the inoculum and dominated both in BHP and semi-continuous reactor. Both the modified Gompertz and first-order models described the DF kinetics well (R2 = 0.97-1.00). HRT of 2.5 d was found to be optimal in terms of maximum hydrogen production rate and hydrogen potential, which were 3.97 and 1.26 times higher, respectively, than in BHP. The hydrolysis constant was highest at HRT of 3 d and was closest to the value obtained in the BHP. Overall, BHP has been shown to be a useful tool for predicting H2 potential and the hydrolysis constant, while the maximum H2 production rate is greatly underestimated.


Assuntos
Reatores Biológicos , Hidrogênio , Fermentação , Cinética , Clostridium
12.
Bioresour Technol ; 376: 128930, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36940877

RESUMO

In this study, acetic acid bacteria (AAB) are isolated from fruit waste and cow dung on the basis of acetic acid production potential. The AAB were identified based on halo-zones produced in the Glucose-Yeast extract-Calcium carbonate (GYC media) agar plates. In the current study, maximum acetic acid yield is reported to be 4.88 g/100 ml from the bacterial strain isolated from apple waste. With the help of RSM (Response surface methodology) tool, glucose and ethanol concentration and incubation period, as independent variable showed the significant effect of glucose concentration and incubation period and their interaction on the AA yield. A hypothetical model of artificial neural network (ANN) was also used to compare the predicted value from RSM. Acetic acid production through the biological route can be the sustainable and clean approach to utilizing food waste in circular economy approach.


Assuntos
Ácido Acético , Eliminação de Resíduos , Redes Neurais de Computação , Glucose , Frutas
13.
Bioresour Technol ; 377: 128966, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36990327

RESUMO

Various conductive materials and their dielectric counterparts were used to get deeper insights into contribution of direct interspecies electron transfer (DIET) in improving methanogenesis from highly concentrated volatile fatty acids (12.5 g/L). Potential CH4 yield, maximum CH4 production rate and lag phase were significantly (up to 1.4, 3.9 and 2.0 times, respectively) improved with addition of stainless-steel mesh (SM) and carbon felt (CF) compared to both control and dielectric counterparts (p < 0.05). kapp increased by 82% for SM and 63% for CF compared to control (p < 0.05). Short thick pili-like structures up to 150 nm in width were formed only in CF and SM biofilms, however, were more abundant for SM. Ureibacillus and Limnochordia specific for SM biofilms, and Coprothermobacter and Ca. Caldatribacterium for CF biofilms, were considered electrogenic. Promotion of DIET by conductive materials is governed by many factors, including specificity of electrogenic groups to material surface.


Assuntos
Ácidos Graxos Voláteis , Metano , Transporte de Elétrons , Carbono , Condutividade Elétrica , Aço Inoxidável , Anaerobiose , Reatores Biológicos
14.
Crit Rev Biotechnol ; 43(1): 100-120, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34923890

RESUMO

Glucosamine (GlcN) and its derivatives are in high demand and used in various applications such as food, a precursor for the biochemical synthesis of fuels and chemicals, drug delivery, cosmetics, and supplements. The vast number of applications attributed to GlcN has raised its demand, and there is a growing emphasis on developing production methods that are sustainable and economical. Several: physical, chemical, enzymatic, microbial fermentation, recombinant processing methods, and their combinations have been reported to produce GlcN from chitin and chitosan available from different sources, such as animals, plants, and fungi. In addition, genetic manipulation of certain organisms has significantly improved the quality and yield of GlcN compared to conventional processing methods. This review will summarize the chitin and chitosan-degrading enzymes found in various organisms and the expression systems that are widely used to produce GlcN. Furthermore, new developments and methods, including genetic and metabolic engineering of Escherichia coli and Bacillus subtilis to produce high titers of GlcN and GlcNAc will be reviewed. Moreover, other sources of glucosamine production viz. starch and inorganic ammonia will also be discussed. Finally, the conversion of GlcN to fuels and chemicals using catalytic and biochemical conversion will be discussed.


Assuntos
Quitosana , Glucosamina , Glucosamina/metabolismo , Quitina , Escherichia coli/metabolismo , Fungos/metabolismo
15.
Bioresour Technol ; 369: 128458, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36503099

RESUMO

Energy demands and immense environmental degradation have extorted for production of low-carbon and carbon-neutral fuels. Abundantly available lignocellulosic biomass is second-generation feedstock which has potential to produce biofuels. Among all biofuels, biohydrogen is carbon neutral and sustainable biofuel which can be produced by thermochemical conversion routes mainly gasification. However, there are still numerous unsolved challenges related to physicochemical properties of lignocellulosic biomass. To tackle these issues, physical, chemical and thermal pretreatment methods can be employed to improve these properties and further strengthen usability of biomass for biohydrogen production. Pelletization, torrefaction and hydrothermal carbonization pretreatment have shown significant results for treating biomass and biohydrogen enhancement. This study reviews physical and thermal pretreatment and its effect on biohydrogen yield. Framework of techno-economic analysis of processes is provided for examining feasibility of required pretreatments. This sustainable approach will help to reduce emissions and promote concept of bioenergy with carbon capture and storage.


Assuntos
Biocombustíveis , Lignina , Biomassa , Lignina/química , Carbono
16.
Innovations (Phila) ; 17(5): 392-400, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36226666

RESUMO

OBJECTIVE: This subgroup analysis aimed to evaluate the effect of comorbidities on infrapopliteal angioplasty outcomes in patients with chronic limb-threatening ischemia (CLTI). METHODS: This was an observational study evaluating eligible CLTI patients aged >18 years who underwent infrapopliteal angioplasty between April 2014 and May 2017 at a tertiary care center. Subgroup analyses were based on (1) baseline glycated hemoglobin (HbA1c ≤6.5% vs >6.5%), (2) presence/absence of chronic kidney disease (CKD), and (3) control of lipid parameters. RESULTS: A total of 231 patients with 332 infrapopliteal vessels were treated. While diabetes was prevalent in all participants, hypertension, coronary artery disease, and CKD were reported in 76.6%, 46.3%, and 25.5% of patients at baseline, respectively. The overall technical success rate was 84.4%, and the patency rate at 6 months was 82.04%. Patency at 6 months, wound healing, in-line flow, and complete plantar arch formation were numerically higher in patients with HbA1c ≤6.5% versus >6.5%, but all comparisons were nonsignificant. According to multivariable analysis, the odds of wounds not healing was 2.38 times higher (odds ratio [OR] = 2.4, 95% confidence interval [CI]: 1.2 to 4.5) and developing plantar arch was 5.88 times higher (OR = 5.9, 95% CI: 1.3 to 25) among patients with CKD compared with patients without CKD. CONCLUSIONS: The 6-month outcomes of infrapopliteal angioplasty may be better in patients with controlled versus uncontrolled glycemic levels. Control of lipid parameters may not have a significant influence on outcomes, especially in patients on statin therapy. The short-term outcomes may be similar in patients with and without CKD.


Assuntos
Doença Arterial Periférica , Insuficiência Renal Crônica , Humanos , Artéria Poplítea/cirurgia , Doença Arterial Periférica/complicações , Doença Arterial Periférica/epidemiologia , Doença Arterial Periférica/terapia , Salvamento de Membro , Isquemia/epidemiologia , Isquemia/terapia , Isquemia/etiologia , Isquemia Crônica Crítica de Membro , Amputação Cirúrgica , Hemoglobinas Glicadas , Grau de Desobstrução Vascular , Estudos Retrospectivos , Resultado do Tratamento , Angioplastia , Fatores de Risco , Insuficiência Renal Crônica/etiologia , Lipídeos
17.
Microbiol Res ; 265: 127216, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36202006

RESUMO

Still, in the current period, non-renewable energy sources have contributed to fulfill the current energy requirement and it causes the deficit of available stocks with emission of pollutant byproducts components. In recent years, efforts were made to harness the sustainable/ renewable fuels from renewable sources/ waste, complex organic matters including biomass at global level. Researchers have put attention on harnessing energy from wastewater and MFCs systems. This MFC approach utilizes the wastewater as feed/ carbon sources to generate bioenergy such as bio- hydrogen and electricity in a sustainable and efficient way via completing the wastewater treatment. This approach consists of anode and cathode electrodes with proton exchange membrane (PEM). Microbial fuel cells are utilized with other effective approaches (anaerobic digestion/ fermentation, local demand-based-MFC approach) that are applied to utilize biowastes for microbial cell growth and electron emission. This review discusses the recent and technologically advanced approach such as microbial fuel cells (MFCs). MFCs can apply to fulfill the increasing trends of global energy demand, found with more utilization in home appliances in urban areas, industrial tasks and transportation sectors. Last few decades, there have been recent modifications in MFCs configurations and design that have improved performance of MFCs. Recent design and configuration of MFCs have shown the removal of maximum chemical oxygen demand (up to 94-97%) with generation maximum current output (up to 5.23 mA) from wastewater. This review presents a comprehensive collection of recent information about technologies and design of MFCs with implementation of microbial electrogene with development of wastewater treatment having sustainable fuel/ energy generation at an effective level.


Assuntos
Fontes de Energia Bioelétrica , Poluentes Ambientais , Carbono , Hidrogênio , Nutrientes , Prótons , Águas Residuárias
18.
Chemosphere ; 307(Pt 4): 136175, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36030942

RESUMO

Present study aims to investigate how is soil affected following irrigation with treated effluents of different origins by analysing the bacterial diversity, metabolic diversity and antibiotic resistance genes (ARGs). Comparative analysis with previously reported ARGs in effluents was performed to understand the mobility of ARGs from treated wastewater to the irrigated soil with respect to the control soil regimen. Acinetobacter, Burkholderia and Pseudomonas were observed as the most abundant genera in all the samples. The metabolic gene abundance of all the samples suggests a prominent contribution to natural mineral recycling. Most abundant ARGs observed encode resistance for clindamycin, kanamycin A, macrolides, paromomycin, spectinomycin and tetracycline. Treated effluent reuse did not appear to enhance the ARG levels in soils in most cases except for institutional treatment site (M), where the ARGs for aminoglycosides, ß-lactams and sulfonamides were found to be abundantly present in both treated effluent and the irrigated soil. This study finds the importance of wastewater treatment from different origins and the impact of treated wastewater reuse in irrigation. This study also emphasises on the better understanding of ARGs mobility from water to soil.


Assuntos
Esgotos , Solo , Antibacterianos/análise , Antibacterianos/farmacologia , Bactérias/genética , Clindamicina , Resistência Microbiana a Medicamentos/genética , Genes Bacterianos , Canamicina , Macrolídeos , Paromomicina , Microbiologia do Solo , Espectinomicina , Sulfonamidas , Tetraciclinas/análise , Águas Residuárias/análise , Água/análise , beta-Lactamas/análise
19.
Bioresour Technol ; 360: 127596, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35809870

RESUMO

Agricultural and food waste have become major issue affecting the environment and climate owing to growing population. However, such wastes have potential to produce renewable fuels which will help to meet energy demands. Numerous valorization pathways like anaerobic digestion, pyrolysis, composting and landfilling have been employed for treating such wastes. However, it requires integrated system that could utilize waste and promote circular bioeconomy. This review explores integration of anaerobic digestion and pyrolysis for treating agricultural and food waste. Proposed system examines the production of biochar and pyro-oil by pyrolysis of digestate. The use of this biochar for stabilizing anaerobic digestion process, biogas purification and soil amendment will promote the circular bioeconomy. Kinetic models and framework of techno-economic analysis of system were discussed and knowledge gaps have been identified for future research. This system will provide sustainable approach and offer carbon capture and storage in form of biochar in soil.


Assuntos
Pirólise , Eliminação de Resíduos , Anaerobiose , Biocombustíveis , Alimentos , Solo
20.
Bioresour Technol ; 351: 127085, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35358673

RESUMO

Agricultural residues play a pivotal role in meeting the growing energy and bulk chemicals demand and food security of society. There is global concern about the utilization of fossil-based fuels and chemicals which create serious environmental problems. Biobased sustainable fuels can afford energy and fuels for future generations. Agro-industrial waste materials can act as the alternative way for generating bioenergy and biochemicals strengthening low carbon economy. Processing of pineapple generates about 60% of the weight of the original pineapple fruit in the form of peel, core, crown end, and pomace that can be converted into bioenergy sources like bioethanol, biobutanol, biohydrogen, and biomethane along with animal feed and vermicompost as described in this paper. This paper also explains about bioconversion process towards the production of various value-added products such as phenolic anti-oxidants, bromelain enzyme, phenolic flavour compounds, organic acids, and animal feed towards bioeconomy.


Assuntos
Ananas , Biocombustíveis , Agricultura , Animais , Biocombustíveis/análise , Carbono , Resíduos Industriais/análise
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