Discover insights from thousands of peer-reviewed papers on microbial electrochemical systems
Yuan Yan, Yajun Wang, Tianjing Chen et al.
Applied Sciences · 2023
Antibiotics are refractory pollutants that have been widely found in various environmental media such as soil and surface water. Existing sewage treatments perform poorly at preventing antibiotics in urban sewage from polluting natural environments. In this study, we designed a bioelectrically enhanced bioretention cell system (bioretention cell-microbial fuel cell, BRC-MFC) that utilizes the unique structure of the BRC system to improve the removal of sewage antibiotics. This new system can efficiently remove antibiotics by using a synergy of plant absorption, filler adsorption, filler filtration and microbial degradation. To study the influences of multiple-antibiotics stress on the decontamination performance of BRC-MFC, ofloxacin (OFLX) and tetracycline (TC) were selected as target antibiotics, and five BRC-MFCs were built to treat sewage containing antibiotics of different concentrations. The concentrations of pollutant in the influent and effluent were measured and the pollutant removal performance of BRC-MFC was studied. The diversity of rhizosphere microorganisms and the abundance of denitrifying functional genes were analyzed. Experimental results showed that over 90% of OFLX and TC in each BRC-MFC were removed, with the removal rates positively correlating with the concentration of antibiotics. In addition, the removal rates of chemical oxygen demand (COD) in BRC-MFC were both over 90%, while the removal rate of total nitrogen (TN) was around 70%. Meanwhile, antibiotics could significantly improve the removal of ammonia nitrogen (NH4+-N, p < 0.01). The microbial richness decreased, and we found that combined antibiotic stress on microorganisms was stronger than single antibiotic stress. The abundance of denitrifying functional genes was reduced by antibiotic stress. The results of this study provide reference values for other projects focusing on removing various antibiotics from domestic sewage using BRC-MFC.
Payel Choudhury, Ria Majumdar, Tarun Kanti Bandyopadhyaya
Journal of Electrochemical Science and Engineering · 2021
To investigate the performance of microbial fuel cell (MFC) with a single-chamber membrane, Pseudomonas aeruginosa is used as a bio catalyst for various synthetic wastewaters rich in carbohydrate and is compared with real dairy wastewater in this experiment. Therefore, the choice of appropriate carbon, nitrogen, NaCl, inoculum content, temperature, and pH process parameters are used for preparing synthetic wastewater was agreed upon by one-variable-at-a time approach. Maximum levels of voltage generation attained from the synthetic wastewater was 485 mV when supplemented with 1.5 % of lactose as a source of carbon, 0.3 % of ammonium chloride as a decent nitrogen source, 0.03 % of NaCl, inoculum concentration of 3 %, the temperature at 37 oC and pH 7. On the other hand, the maximum voltage attained with real dairy wastewater was 561 mV with high chemical oxygen demand (COD) value of 801 mg l-1. The maximum power density obtained from dairy wastewater was 73.54 mW m-2. Thus, High voltage achieved for MFC operating with real dairy wastewater suggests that it can be used not only for the industrial application to generate more renewable power, but also for the wastewater treatment carried out at the same time.
Luyu Wang, Hongbin Xue, Lei Gong et al.
Research Square · 2022
Abstract Microbial fuel cell (MFC) technology has the function of decarburization and denitrification and is considered advantageous in treating wastewater with a low carbon-nitrogen ratio. In the current study, MFC treats different concentrations of nitrate nitrogen. And compared with abiotic electrode treatment and microbial treatment only, MFC showed obvious treatment advantages. The best treatment effect was recorded when the nitrate-nitrogen (NO3-N) concentration was 414 mg/L. The running of the MFC system showed that it produced a stable output voltage up to 0.17 V within 160 h; And showed a power density up to 40.18 mW/m2, which was 1.58 times of M1 (138 mg/L, 25.49 mW/m2), 4.48 times of non-biological electrode; The removal rate of NO3-N was 97.48%, but the lack of anode electron supply resulted in the incomplete reduction of nitrate nitrogen and accumulation of nitrite-nitrogen (188.83 mg/L). Nitrate-nitrogen concentration in the study had no significant impact on microbial population diversity. However, the relative abundance of Proteobacteria increased from 47.3% to 65.4% when NO3-N concentration increased from 138 to 414 mg/L. Results from this study are promising for a theoretical basis for microbial cathode denitrification.
Ankisha Vijay, Prakash C. Ghosh, Suparna Mukherji
Energies · 2023
Saline wastewater pollution is a critical issue that needs to be addressed. The present study focused on the development of a dual-chambered microbial fuel cell (MFC) treating saline wastewater at the anode. Halophilic exo-electrogenic bacteria enriched from seawater (Arabian Sea, Mumbai, India) were used in the anodic chamber of the MFC. Denitrification using denitrifying bacteria was employed in the cathodic chamber. The maximum power density was significantly increased from 96.77 mW/m2 to 162.09 mW/m2 with a rise in NaCl concentration from 20 to 40 g/L. Nitrate removal in the cathode chamber increased from 80 ± 3% to 89 ± 3.2% with increase in salt concentration from 20 g/L to 40 g/L and concomitantly COD removal in the anode chamber increased from 76 ± 3.8% to 83 ± 4%. Cyclic voltammetry (CV) analysis revealed higher electrochemical activity at 40 g/L salt concentration. Electrochemical impedance spectroscopy (EIS) analysis exhibited that charge transfer and solution resistances were lower when the salinity was increased. Microbial community analysis revealed the presence of Clostridium, Shewanella, and Bacillus as the most abundant genera in the anodic chamber. This study demonstrated the dual applicability of the system targeted for removal of organics from saline wastewater and nitrate removal from contaminated wastewater accompanied by power generation from the MFC.
Verjesh Kumar Magotra, Sunil Kumar, T W Kang et al.
Scientific reports · 2020
The acute problem of eutrophication increasing in the environment is due to the increase of industrial wastewater, synthetic nitrogen, urine, and urea. This pollutes groundwater, soil and creates a danger to aquatic life. Therefore, it is advantageous to use these waste materials in the form of urea as fuel to generate power using Microbial Fuel Cell (MFC). In this work, we studied the compost soil MFC(CSMFC) unlike typical MFC with urea from the compost as fuel and graphite as a functional electrode. The electrochemical techniques such as Cyclic Voltammetry, Chronoamperometry are used to characterise CSMFC. It is observed that the CSMFC in which the compost consists of urea concertation of 0.5 g/ml produces maximum power. Moreover, IV measurement is carried out using polarization curves in order to study its sustainability and scalability. Bacterial studies were also playing a significant role in power generation. The sustainability study revealed that urea is consumed in CSMFC to generate power. This study confirmed that urea has a profound effect on the power generation from the CSMFC. Our focus is to get power from the soil processes in future by using waste like urine, industrial wastewater, which contains much amount of urea.
Lu Liu, Xiaochen Sun, Wenxin Li et al.
RSC Advances · 2017
Enhancing the activity of the cathode and reducing the voltage for electrochemical hydrodechlorination of chlorohydrocarbon were always the challenges in the area of electrochemical remediation. In this study, a novel cathode material of Ni-doped graphene generated by Ni nanoparticles dispersed evenly on graphene was prepared to electrochemically dechlorinate PCE in groundwater. The reduction potential of Ni-doped graphene for PCE electrochemical hydrodechlorination was -0.24 V ( vs. Ag/AgCl) determined by cyclic voltammetry. A single MFC with a voltage of 0.389-0.460 V and a current of 0.221-0.257 mA could drive electrochemical hydrodechlorination of PCE effectively with Ni-doped graphene as the cathode catalyst, and the removal rate of PCE was significantly higher than that with single Ni or graphene as the cathode catalyst. Moreover, neutral conditions were more suitable for Ni-doped graphene to electrochemically hydrodechlorinate PCE in groundwater and no byproduct was accumulated.
Yiran Tong, Zhen He
RSC Advances · 2014
Jiayin Ling, Yanbin Xu, Chuansheng Lu et al.
Energies · 2019
The electricity output from microbial fuel cell (MFC) with a microalgae assisted cathode is usually higher than that with an air cathode. The output of electricity from a photosynthetic microalgae MFC was positively correlated with the dissolved oxygen (DO) level in the microalgae assisted biocathode. However, DO is highly affected by the photosynthesis of microalgae, leading to the low stability in the electricity output that easily varies with the change in microalgae growth. In this study, to improve the electricity output stability of the MFC, a partially submerged carbon cloth cathode electrode was first investigated to use oxygen from both microalgae and air, with synthetic piggery wastewater used as the anolyte and anaerobically digested swine wastewater as the catholyte. When the DO levels dropped from 13.6–14.8 to 1.0–1.6 mg/L, the working voltages in the MFCs with partially submerged electrodes remained high (256–239 mV), whereas that for the conventional completely submerged electrodes dropped from 259 to 102 mV. The working voltages (average, 297 ± 26 mV) of the MFCs with the 50% submerged electrodes were significantly (p < 0.05) higher than with other partially or completely submerged electrodes. The associated maximum lipid production from wastewater was 250 ± 42 mg/L with lipid content of 41 ± 6% dry biomass. Although the partially submerged electrode had no significant effects on lipid production or nitrogen removal in wastewater, there was significant improvement in the stability of the electricity generated under variable conditions.
Marcin Zieliński, Paulina Rusanowska, Magda Dudek et al.
Energies · 2024
Photosynthetic microbial fuel cells (pMFCs) are hybrid systems that enable simultaneous wastewater treatment under anaerobic conditions and the generation of electricity by utilizing the potential difference in the anaerobic anode chamber and the oxygenated cathode chamber. Dairy wastewater with a concentration of 2000 mg COD/L was treated in the anode of a batch pMFC. In the cathode chamber, Chlorella vulgaris or Arthrospira platensis was cultivated in synthetic medium, and next in diluted effluent from the anode chamber. The highest power density of 91 mW/m2 was generated by the pMFC with the cultivation of Arthrospira platensis. Higher values of dissolved oxygen remained during the dark phase in the cathodic medium with Arthrospira platensis cultivation than with Chlorella vulgaris. This depletion of oxygen significantly decreased voltage generation, which during the light phase increased again to the maximum values. The COD removal achieved in the anodic chamber was 87%. The efficiency of nitrogen removal in the cathode chamber during the cultivation of Arthrospira platensis and Chlorella vulgaris was about 78% and 69%, respectively. The efficiency of phosphorus removal in the cathode chamber with the cultivation of Arthrospira plantensis and Chlorella vulgaris was 58% and 43%, respectively. This study has shown that the introduction of Arthrospira platensis into the cathode chamber is more effective than that of Chlorella vulgaris.
Huichao Zhang, Qian Yan, Zhongyi An et al.
Frontiers in Microbiology · 2022
Photosynthetic microbial fuel cell (PMFC) based on algal cathode can integrate of wastewater treatment with microalgal biomass production. However, both the traditional suspended algae and the immobilized algae cathode systems have the problems of high cost caused by Pt catalyst and ion-exchange membrane. In this work, a new equipment for membrane-free PMFC is reported based on the optimization of the most expensive MFC components: the separator and the cathode. Using a revolving algae-bacteria biofilm cathode in a photosynthetic membrane-free microbial fuel cell (RAB-MFC) can obtain pollutants removal and algal biomass production as well as electrons generation. The highest chemical oxygen demand (COD) removal rates of the anode and cathode chambers reached 93.5 ± 2.6% and 95.8% ± 0.8%, respectively. The ammonia removal efficiency in anode and cathode chambers was 91.1 ± 1.3% and 98.0 ± 0.6%, respectively, corresponding to an ammonia removal rate of 0.92 ± 0.02 mg/L/h. The maximum current density and power density were 136.1 mA/m2 and 33.1 mW/m2. The average biomass production of algae biofilm was higher than 30 g/m2. The 18S rDNA sequencing analysis the eukaryotic community and revealed high operational taxonomic units (OTUs) of Chlorophyta (44.43%) was dominant phyla with low COD level, while Ciliophora (54.36%) replaced Chlorophyta as the dominant phyla when COD increased. 16S rDNA high-throughput sequencing revealed that biofilms on the cathode contained a variety of prokaryote taxa, including Proteobacteria, Bacteroidota, Firmicutes, while there was only 0.23–0.26% photosynthesizing prokaryote found in the cathode biofilm. Collectively, this work demonstrated that RAB can be used as a bio-cathode in PMFC for pollutants removal from wastewater as well as electricity generation.
Daniele Cecconet, Arianna Callegari, Andrea Capodaglio
Energies · 2018
Groundwater contamination is a major issue for human health, due to its largely diffused exploitation for water supply. Several pollutants have been detected in groundwater; amongst them arsenic, cadmium, chromium, vanadium, and perchlorate. Various technologies have been applied for groundwater remediation, involving physical, chemical, and biological processes. Bioelectrochemical systems (BES) have emerged over the last 15 years as an alternative to conventional treatments for a wide variety of wastewater, and have been proposed as a feasible option for groundwater remediation due to the nature of the technology: the presence of two different redox environments, the use of electrodes as virtually inexhaustible electron acceptor/donor (anode and cathode, respectively), and the possibility of microbial catalysis enhance their possibility to achieve complete remediation of contaminants, even in combination. Arsenic and organic matter can be oxidized at the bioanode, while vanadium, perchlorate, chromium, and cadmium can be reduced at the cathode, which can be biotic or abiotic. Additionally, BES has been shown to produce bioenergy while performing organic contaminants removal, lowering the overall energy balance. This review examines the application of BES for groundwater remediation of arsenic, cadmium, chromium, vanadium, and perchlorate, focusing also on the perspectives of the technology in the groundwater treatment field.
Rauno Lust, Jaak Nerut, Kuno Kasak et al.
Water · 2020
Assessments of groundwater aquifers made around the world show that in many cases, nitrate concentrations exceed the safe drinking water threshold. This study assessed how bioelectrochemical systems could be used to enhance nitrate removal from waters with low organic carbon concentrations. A two-chamber microbial electrosynthesis cell (MES) was constructed and operated for 45 days with inoculum that was taken from a municipal wastewater treatment plant. A study showed that MES can be used to enhance nitrate removal efficiency from 3.66% day−1 in a control reactor to 8.54% day−1 in the MES reactor, if a cathode is able to act as an electron donor for autotrophic denitrifying bacteria or there is reducing oxygen in a cathodic chamber to favor denitrification. In the MES, greenhouse gas emissions were also lower compared to the control. Nitrous oxide average fluxes were −639.59 and −9.15 µg N m−2 h−1 for the MES and control, respectively, and the average carbon dioxide fluxes were −5.28 and 43.80 mg C m−2 h−1, respectively. The current density correlated significantly with the dissolved oxygen concentration, indicating that it is essential to keep the dissolved oxygen concentration in the cathode chamber as low as possible, not only to suppress oxygen’s inhibiting effect on denitrification but also to achieve better power efficiency.
Geremia Sassetto, Laura Lorini, Agnese Lai et al.
Catalysts · 2024
A new membrane-less bioelectrochemical reactor configuration was developed for contaminated groundwater remediation. The new bioelectrochemical reactor configuration was inspired by the utilisation of a permeable reactive barrier (PBR) configuration with no separation membrane. The corresponding reactive zones were created by using graphite granules and mixed metal oxide (MMO) electrodes to stimulate the reductive and oxidative biological degradation of chlorinated aliphatic hydrocarbons. In the present study, the PBR-like bioelectrochemical reactor has been preliminarily operated with synthetic contaminated groundwater, testing the reductive dechlorination activity on cis-dichloroethylene (cisDCE). Moreover, to assess the effects of competing anions presence for the electron donor (i.e., the cathode), the synthetic wastewater contained sulphate and nitrate anions. In the PBR-like reactor operation, nearly all cisDCE was removed in the initial sampling port, with only VC detected as the observable RD product. During the same biotic test of the PRB reactor, the presence of both the reductive dechlorination and anions reduction was confirmed by the complete nitrate reduction in the cathodic chamber of the PRB reactor. On the contrary, sulphate reduction showed a lower activity; indeed, only 25% of the influent sulphate was removed by the PRB reactor.
Desmond Ato Koomson, Jingyu Huang, Guang Li et al.
Membranes · 2021
The recirculatory microbial desalination cell-microbial electrolysis cell (MDC-MEC) coupled system is a novel technology that generates power, treats wastewater, and supports desalination through eco-friendly processes. This study focuses on the simultaneous efficient removal of Fe2+ and Pb2+ in the MEC and ammonium ions in the MDC. It also evaluates the performances of dual-chambered MEC (DCMEC) and single-chambered MEC (SCMEC), coupled with MDC with Ferricyanide as catholyte (MDCF) in heavy metals (Pb2+ and Fe2+) removal, in addition to the production of voltage, current, and power within a 48-h cycle. The SCMEC has a higher Pb2+ (74.61%) and Fe2+ (85.05%) removal efficiency during the 48-h cycle than the DCMEC due to the simultaneous use of microbial biosorption and the cathodic reduction potential. The DCMEC had a higher current density of 753.62 mAm-2 than that of SCMEC, i.e., 463.77 mAm-2, which influences higher desalination in the MDCF than in the SCMEC within the 48-h cycle. The MDCF produces a higher voltage (627 mV) than Control 1, MDC (505 mV), as a power source to the two MECs. Stable electrolytes' pH and conductivities provide a conducive operation of the coupled system. This study lays a solid background for the type of MDC-MEC coupled systems needed for industrial scale-up.
Akshay Jain, Zhen He
npj Clean Water · 2018
AbstractBioelectrochemical systems (BES) have been intensively studied as a new technology for wastewater treatment. However, the treatment efficiency of BES anodes is limited and the anode effluent usually cannot be directly discharged or reused. To enhance the treatment, BES cathodes may be used for additional treatment of selected contaminants. This has been investigated in a number of approaches, which can be grouped into cathode-stimulated treatment and cathode-supported treatment. The former involves electron transfer directly to reduce contaminants like nitrate or dye compounds, while the latter can accomplish contaminant removal by aerobic oxidation, algal growth, production of strong oxidants for advanced oxidation, and/or membrane treatment. This paper aims to provide a concise view and discussion on the cathode-promoted wastewater treatment in BES, analyze challenges pertaining to the cathode treatment, and offer suggestions on the future development of BES for maximized treatment performance.
Jin Sun, Hongrui Cao, Zejie Wang
Processes · 2020
Nitrogenous compounds attract great attention because of their environmental impact and harmfulness to the health of human beings. Various biological technologies have been developed to reduce the environmental risks of nitrogenous pollutants. Bioelectrochemical systems (BESs) are considered to be a novel biological technology for removing nitrogenous contaminants by virtue of their advantages, such as low energy requirement and capacity for treating wastewaters with a low C/N ratio. Therefore, increasing attention has been given to carry out biological processes related to nitrogen removal with the aid of cathodic biofilms in BESs. Prior studies have evaluated the feasibility of conventional biological processes including nitrification, denitrification, and anaerobic ammonia oxidation (anammox), separately or combined together, to remove nitrogenous compounds with the help of BESs. The present review summarizes the progress of developments in BESs in terms of the biological process, cathodic biofilm, and affecting factors for efficient nitrogen removal.
Marc Viñas, Maite Martínez-Eixarch, Abraham Esteve-Núñez et al.
· 2024
The decomposition of buried straw in rice fields during post-harvest generates volatile fatty acids (VFA), thus activating methanogenesis (1). In this study, bioelectrochemical biosensors were used to measure the in-situ electrical current produced by electroactive microorganisms, related to the biodegradation of buired straw, in outdoor mesocosms containing rice paddy soil from the Ebro Delta (Spain) .Three biosensors (BS1-BS3), based on bioelectrochemical cells buried in the water saturated soil (at a -10 cm), were used in 3 rice paddy soil mesocosms, with a poised working electrode (graphite) potential at +0.2V vs Ag/AgCl, by using a potentiostat. During 5 months (November 2022-March 2023), the production of electrical current (I) in the soil mesocosms was monitored using chronoamperometry. The presence of electroactive microbial biofilms on the electrodes was assessed by cyclic voltammetry (CV). Simultaneously, soil chemical parameters were monitored (total and soluble COD, VFA and CH4 emission), and microbial diversity (bacteria and archaea) in the soil and the electrodes biofilms was assessed by 16S rRNA-metabarcoding.Chronoamperometry data in BS1-BS3 showed a marked current production curve from the day 3 to 5 after straw addition, with an I max of 110-180µA (4.26-6.91 µA cm-2) at day 10, remaining higher than the baseline for 30-45 days, and concomitant with VFA accumulation (69-28 mg-eq Acetic kg-1 soil , 7-40 days) and a high emission rate of CH4 (198.1±101.0 mg C-CH4· m-2 soil · h-1 7 days after straw addition. The CV revealed electroactive profiles in the 3 biosensors, similar in BS1-BS2 (oxidation peak -0.16/-0.22 V vs Ag/AgCl, similar to Geobacter), and different in BS3 (oxidation peak +0.26 V vs Ag/AgCl), revealing different electroactive microbial communities. 16S-based metataxonomy revealed an enrichment of well known electroactive bacteria on the three anode biofilm but with different relative predominances, encompassing mainly Desulfobulbus in BS1-BS3, Geobacter mainly in BS1, but in less predominance in BS2 and BS3, Proteiniclasticum solely in BS3, and Clostridium in BS2 and BS3. Methanogenic archaea such as Methanosarcina and Methanobacterium were also depicted on the anode, but at lower relative abundance than observed in the soil, where ammonium oxidizing archaea (Nitrososphaera and candidatus Nitrosocaldus) were also predominant.The results showed the capacity of the bioelectrochemical-based biosensors for real time detection of microbial in-situ degradation processes of buried edible organic carbon (straw) in the soil of rice paddy fields, also linked to methane emissions.AknowledgementsThis research was funded by Agencia Estatal de Investigación (PID2019-111572RB-I00/AEI/10.13039/501100011033 ) from Spain. References1. Martínez-Eixarch, M., Alcaraz, C., Viñas, M., Noguerol, J., Aranda, X., Prenafeta-Boldú, F. X., Saldaña-De la Vega, J.A., Català, M.M. & Ibáñez, C. (2018). Neglecting the fallow season can significantly underestimate annual methane emissions in Mediterranean rice fields. PLoS One, 13(5), e0198081. DOI: 10.1371/journal.pone.0202159
Manon Coone, Isabel Vanoverberghe, Shira Houwenhuyse et al.
bioRxiv (Cold Spring Harbor Laboratory) · 2023
Abstract The depletion of oxygen as a result of increased stratification and decreased oxygen solubility is one of the most significant chemical changes occurring in aquatic ecosystems as a result of global environmental change. Hence, more aquatic organisms will be exposed to hypoxic conditions over time. Deciphering the effects of hypoxia on strong ecological interactors in this ecosystem’s food web is critical for predicting how aquatic communities can respond to such an environmental disturbance. Here, (sub-)lethal effects of hypoxia and whether these are genotype specific in Daphnia , a keystone species of freshwater ecosystems, are studied. This is especially relevant upon studying genetic responses with respect to phenotypic switches (G x E interactions) upon environmental stress. Further, we investigated the effect of hypoxia on the Daphnia microbial community to test if the microbiome plays a role in the phenotypic switch and tolerance to hypoxia. For this, two Daphnia genotypes were exposed for two weeks to either hypoxia or normoxia and host performance was monitored together with changes in the host associated and free-living microbial community after this period. We found G x E interactions for some of the tested Daphnia performance traits. The microbial community responded to hypoxia stress with responses in the bacterioplankton and in the Daphnia associated microbial community with respect to species richness and community composition and structure. The latter response was different for the two genotypes suggesting that the microbiome plays an important role in G x E interactions with respect to hypoxia tolerance in Daphnia , but further testing (e.g. through microbiome transplants) is needed to confirm this.
Johannes Rousk, Lettice Hicks
· 2020
&lt;p&gt;Understanding the role of ecological communities in maintaining multiple ecosystem processes is a central challenge in ecology. Soil microbial communities perform vital ecosystem functions, such as the decomposition of organic matter to provide plant nutrition. However, despite the functional importance of soil microorganisms, attribution of ecosystem function to particular constituents of the microbial community has been impeded by a lack of information linking microbial processes to community structure.&lt;/p&gt;&lt;p&gt;Here, we propose a new conceptual framework to determine how microbial communities influence ecosystem processes, by applying a &amp;#8220;top-down&amp;#8221; approach. Looking from the &amp;#8220;top&amp;#8221;, we first view the microbial community associated with a specific function as a whole, and describe the dependence of microbial community processes on environmental factors (e.g. the intrinsic temperature dependence of bacterial growth rates), allowing us to define the aggregate functional response curve of the community. We then demonstrate that the whole community contribution to ecosystem function can be predicted, by parameterising the functional response curve with current environmental conditions. In a final step, we show how this functional information can be linked to the taxonomic community composition (amplicon assessments of microbial community composition) in order to identify &amp;#8220;biomarker&amp;#8221; taxa that capture microbial communities&amp;#8217; regulation of ecosystem processes and the susceptibility of microbial community structure and function to environmental change. Ultimately, these biomarkers may be used as a diagnostic tool, enabling predictions of ecosystem function from community composition information combined with environmental metadata.&lt;/p&gt;
Johannes Rousk, Lettice Hicks
· 2021
&lt;p&gt;Soil microbial communities perform vital ecosystem functions, such as the decomposition of organic matter to provide plant nutrition. However, despite the functional importance of soil microorganisms, attribution of ecosystem function to particular constituents of the microbial community has been impeded by a lack of information linking microbial function to community composition and structure. Here, we propose a function-first framework to predict how microbial communities influence ecosystem functions.&lt;/p&gt;&lt;p&gt;We first view the microbial community associated with a specific function as a whole, and describe the dependence of microbial functions on environmental factors (e.g. the intrinsic temperature dependence of bacterial growth rates). This step defines the aggregate functional response curve of the community. Second, the contribution of the whole community to ecosystem function can be predicted, by combining the functional response curve with current environmental conditions. Functional response curves can then be linked with taxonomic data in order to identify sets of &amp;#8220;biomarker&amp;#8221; taxa that signal how microbial communities regulate ecosystem functions. Ultimately, such indicator taxa may be used as a diagnostic tool, enabling predictions of ecosystem function from community composition.&lt;/p&gt;&lt;p&gt;In this presentation, we provide three examples to illustrate the proposed framework, whereby the dependence of bacterial growth on environmental factors, including temperature, pH and salinity, is defined as the functional response curve used to interlink soil bacterial community structure and function. Applying this framework will make it possible to predict ecosystem functions directly from microbial community composition.&lt;/p&gt;
Nanostructured Carbon Materials for Catalysis · 2015
In this chapter we review the most relevant applications of nanocarbons as support for photocatalysis. Particular attention is given to comparison with conventional supports for environmental applications. The combination of nanocarbons with metal oxides, and particularly with TiO2, constitutes an important part of this chapter. Different reaction mechanisms are highlighted considering the specific properties that each nanocarbon material takes to the composite material.
Swapnil R. Bankar
Current Organocatalysis · 2019
<P>Background: In recent years, green organic transformation has become a challenge for a chemist in areas like social sector, health, and environment. Literature survey revealed that a nano magnetite supported heterogeneous catalysis is an emergent field with huge application in chemical synthesis. </P><P> Objective: In the present article, the aim was to develop a simple and facile method to carry organic reaction under benign media. So, the focus was on the synthesis of nano-magnetite supported molybdenum catalyst and its application in β-enaminones synthesis. </P><P> Methods: Magnetically recyclable heterogeneous ferrite-molybdenum catalyst was prepared by simple impregnation method. The synthesized nanocatalyst Fe-Mo was well analysed by spectroscopic techniques like X-ray diffraction analysis, X-ray photoelectron spectroscopy, transmission electron microscopy, field-emission gun scanning electron microscopy and vibrating-sample magnetometry. The functionalized nanocatalyst Fe-Mo was employed in the synthesis of β-enaminones under solvent free condition. </P><P> Results: The competency of synthesized nanocatalyst-Fe-Mo was observed to be good for the synthesis of β-enaminones derivatives under microwave irradiation and gave excellent yield (86-96%) of the product. The catalyst was recycled for more than five consecutive runs without significant loss in its activity. </P><P> Conclusion: In the present research article, synthesis of highly active, magnetically recyclable Fe- Mo nanocatalyst was obtained from easily available precursor. The MNP was stable under investigated conditions and effective in β-enaminones synthesis. The simple eco-friendly method, low catalyst loading, short transformation time, and reusability of the catalyst thoroughly follow the sustainable protocol.</P>
Vivek Srivastava
Letters in Organic Chemistry · 2024
Abstract: The preparation and characterization of SBA-15 supported Ni catalysts with varying metal loading (1, 2, and 3% by weight) was carried out using the impregnation technique, followed by a rigorous characterization using advanced analytical techniques. The catalytic performance of the synthesized catalysts was evaluated for the Wittig-type olefination reaction, and it was found that the SBA- 15-3Ni catalyst exhibited superior activity for this reaction under mild reaction conditions (70°C and 1 hour). The corresponding stilbenes were obtained in good yield, although with low to average diastereoselectivity. An important feature of this protocol is that the proposed methodology is especially efficient for the synthesis of stilbenes since no additives are required to serve as a hydrogen acceptor. Moreover, the new catalytic system was successfully employed for the synthesis of polymethoxylated and polyhydroxylated stilbenes, including resveratrol and DMU-212, with high yield and easy product isolation. A key advantage of this protocol is that the catalysts can be reused for up to 5 runs without significant loss in catalytic activity, which makes this approach highly sustainable and cost-effective. Additionally, the ligand-free approach proposed in this study is an added advantage, which makes it more attractive for large-scale synthesis of biologically active compounds.
SAKTHI SARAVANAN, Periyasamy Sivanandi
Research Square · 2022
Abstract The exhaustion of natural resources has occasioned the profit margin of oil products to increase dramatically, prompting the use of sustainable fuels like as biofuel. In the proposed investigation, biofuel was developed from castor oil utilizing Fe 3 O 4 @MnO 2 NCs as a heterogeneous catalyst for the transesterification process. X-Ray Diffraction evaluation acknowledged the nanocatalyst's single phase. Scanning Electron Microscopy revealed the spherical morphology of the consolidated nanocatalyst. The magnetic characteristics were examined using a vibrating sample magnetometer. Atomic Force Microscopy demonstrated that the catalyst exhibited has a greater surface area and unevenness. The yield was achieved was 95 percent (w/w) in 50 minutes at 60 0 C with 15 wt percent catalyst loading and a 12:1 methanol/oil ratio, as acknowledged by a gas chromatograph with mass spectrometer. The findings indicate that Fe 3 O 4 @MnO 2 NCs are an encouraging catalyst for bio-fuels production via heterogeneous catalyzed transesterification under relatively mild response circumstances.
Andreas Gubner
Innovations in Fuel Cell Technologies · 2010
A one dimensional (1D) model for simulating Solid Oxide Fuel Cell (SOFC) isothermal performance with humidified hydrogen and air is introduced. It is based on a set of ordinary differential equations (ODEs) describing the local current density as a function of the flow path for parallel flow SOFCs. Isothermal operation is a reasonable idealisation for laboratory cells placed in comparatively large furnaces, especially when operated at low fuel utilization. Such small scale SOFCs are often used to characterize the electrochemical cell performance. The electrochemical behaviour is modeled by a single constant Area Specific Resistance (ASR) by taking the slope of an experimentally recorded I-V curve. It will be discussed that suitable operating conditions are found at a steam content (fuel humidity) of approx. 50 Vol-% and low fuel utilizations of less than 10 %. Alternatively, the 1D model can be used to calculate the ASR from I-V data directly which is less strict on operating condition requirements. Using the 1D model also allows to convert endurance test data, usually delivering a Vcell(t) data set, at constant electric current into a corresponding ASR(t) data set. The ODE set is solved numerically. Based on this model, a further step is taken by introducing a simple model for describing SOFC degradation during stationary operation. The simple degradation model can be useful as a first approach to more sophisticated life time prediction models and for deriving accelerated life time tests.
Wei Wei, Haoyang Gong, Lin Sheng et al.
Research Square · 2021
Abstract Although humic acid (HA) is a complex natural organic matter, it can potentially harm the environment and human health. In this study, aluminum–air fuel cell electrocoagulation (AAFCEC) was used to remove HAs from water while generating electricity. This device can generate electricity from the anodic oxidation of aluminum without an external power source as well produce an aluminum coagulant. Operating parameters, namely initial pH, electrolyte concentration, and HA concentration, were analyzed to determine the optimal power generation and removal efficiency. Al–Ferron complexation timed spectrophotometry was used to determine the Al speciation distribution in the solution. The power density of the cell reached 313.47 mW/cm 2 for the following conditions: 1 g/L NaCl concentration, 3 cm electrode distance, 20 Ω external resistor, and pH 9. And after about an hour electrolysis, the optimum removal rate of HA was above 99%. The results demonstrate that the AAFCEC is an efficient and eco-friendly water treatment process, and it could be further developed and disseminated in the rural areas and households.
Manuel Razo-Mejia, Sarah Marzen, Griffin Chure et al.
bioRxiv (Cold Spring Harbor Laboratory) · 2019
Abstract Given the stochastic nature of gene expression, genetically identical cells exposed to the same environmental inputs will produce different outputs. This heterogeneity has been hypothesized to have consequences for how cells are able to survive in changing environments. Recent work has explored the use of information theory as a framework to understand the accuracy with which cells can ascertain the state of their surroundings. Yet the predictive power of these approaches is limited and has not been rigorously tested using precision measurements. To that end, we generate a minimal model for a simple genetic circuit in which all parameter values for the model come from independently published data sets. We then predict the information processing capacity of the genetic circuit for a suite of biophysical parameters such as protein copy number and protein-DNA affinity. We compare these parameter-free predictions with an experimental determination of protein expression distributions and the resulting information processing capacity of E. coli cells. We find that our minimal model captures the scaling of the cell-to-cell variability in the data and the inferred information processing capacity of our simple genetic circuit up to a systematic deviation.
Ouendi Fatima, Rachid Zentar, Hongwei Wang
Research Square · 2021
Abstract The authors have requested that this preprint be removed from Research Square.
Anthony J. Abel, Douglas S. Clark
bioRxiv (Cold Spring Harbor Laboratory) · 2020
Abstract Mediated microbial electrosynthesis (MES) represents a promising strategy for the capture and conversion of CO 2 into carbon-based products. We describe the development and application of a comprehensive multiphysics model to analyze a formate-mediated MES reactor. The model shows that this system can achieve a biomass productivity of ∼1.7 g L -1 hr -1 but is limited by a competitive trade-off between O 2 gas/liquid mass transfer and CO 2 transport to the cathode. Synthetic metabolic strategies are evaluated for formatotrophic growth, which can enable an energy efficiency of ∼21%, a 30% improvement over the Calvin cycle. However, carbon utilization efficiency is only ∼10% in the best cases due to a futile CO 2 cycle, so gas recycle will be necessary for greater efficiency. Finally, separating electrochemical and microbial processes into separate reactors enables a higher biomass productivity of ∼2.4 g L -1 hr -1 . The mediated MES model and analysis presented here can guide process design for conversion of CO 2 into renewable chemical feedstocks.
Ramona Crainic, Radu Fechete
Preprints.org · 2024
Advanced 1H Nuclear Magnetic Resonance (NMR) relaxometry and diffusometry methods and VIS-nearIR spectroscopy combined with pH, electric conductivity (EC) and totally dissolved solids (TDS) measurements were used to assess the properties of wastewater collected from a chicken slaughterhouse in each step of the treatment process (wastewater before treatment, biologically treated wastewater, chemically treated wastewater and discharged wastewater) and from sludge. The 1H NMR Carr-Purcell-Meiboom-Gill (CPMG) and Pulsed-Gradient-Stimulated-Echo (PGSE) decay curves recorded for all samples of wastewater were analyzed by inverse Laplace transform (ILT) to obtain the distributions of transverse relaxation times T2 and diffusion coefficient D. The VIS-nearIR total absorbance, T2-values, D-values, pH, EC and TDS parameters were used for statistical analysis in principal component analysis (PCA). The 1H T2-distributions measured for the slaughterhouse wastewater lie in two main regions reflecting the amount of dissolved solids or the distribution of undissolved solids mobility. The PCA analysis successfully differentiates between polluted and less polluted types of wastewater and sludge. The wastewater treatment applied by the slaughterhouse is efficient. The recommended methods for wastewater monitoring are the NMR T2- and D-distributions and EC, TDS and NMR-D diffusion coefficient. Finally, Machine Learning AI-algorithms are used to provide prediction maps of wastewater treatment stage.
Kambiz Vaezzadeh Naderi
· 2021
In this study, a three-factor, three-level Box-Behnken design with response surface methodology and quadratic programming were used to maximize the total organic carbon (TOC) removal and minimize the H2O2 residual in the effluent of the combined UV-C/H2O2/VUV system for the treatment of actual slaughterhouse wastewater. The initial TOC concentration (TOCo), the initial concentration of H2O2, and the irradiation time were the three independent variables studied in the design of experiments. The multiple response approach was used to obtain desirability response surfaces at the optimum factor settings. Thus, the optimum conditions to achieve a maximum TOC removal of 46.19% and a minimum H2O2 residual of 1.05% were TOCo of 213 mg/L, H2O2,o of 450 mg/L, and irradiation time of 9 min. The obtained optimal operating conditions were validated with an additional test. Consequently, maximum TOC removal of 45.68% and minimum H2O2 residual of 1.03% were obtained experimentally, confirming the reliability of the statistical model. Keywords: Slaughterhouse Wastewater; Wastewater Treatment; UV-C/H2O2/VUV, Combined Processes; Design of Experiments; Optimization.
Rajesh Sani
· 2020
&lt;p&gt;&lt;strong&gt;Biofilm Engineering Approaches for Improving the Performance of Bioelectrochemical Systems&lt;/strong&gt;&lt;/p&gt; &lt;p&gt;&amp;#160;&lt;/p&gt; &lt;p&gt;&lt;strong&gt;ABSTRACT: &lt;/strong&gt;&lt;/p&gt; &lt;p&gt;Bio-electrochemical devices are realized as promising technologies for a wide range of applications such bioenergy, and in biocommodity engineering.&amp;#160; Bioelectrochemical systems make use of electroactive biofilms as electrocatalysts for converting chemical energy to electrical energy and vice versa. In this presentation, surface engineering of electrodes (using biopolymers such as chitosan/alginate, nanomaterials such as reduced graphene oxide), extremophilic bioprocessing, and biofilm engineering strategies for enhancing the biofilm formation and performance of bio-electrochemical systems will be discussed. This talk will also cover the applications of biofilm for energy and environment.&lt;/p&gt; &lt;p&gt;&amp;#160;&lt;/p&gt; &lt;p&gt;&lt;strong&gt;Keywords:&lt;/strong&gt; Electrochemical devices, Electrode materials, Bioelectricity, Biofilm Engineering, Biopolymers&lt;/p&gt;
Dayakar Thatikayala, Deepak Pant, Booki Min
Reaction Chemistry & Engineering · 2021
Single chamber MES reactor – microbial reduction synthesis of CO 2 to VFA.
Huanhuan Zhao, Chui-Hua Kong
Chemical Engineering Journal · 2018
Amit Jain
European Chemical Bulletin · 2022
Innocent Tayari Mwizerwa, Yu Wang, Xiaoguang Chen
Journal of Environmental Accounting and Management · 2020
Malathi H, Pooja Sharma
Novel Research in Microbiology Journal · 2023
Hana Barak, Asher Brenner, Alex Sivan et al.
Chemosphere · 2020
Water and soil contamination by industrial wastes is a global concern. Biological treatment of industrial wastewater using bioreactors allows the removal of organic matter and nutrients and enables either reuse or safe discharge. Wastewater bioremediation depends in part on the microbial communities present in the bioreactor. To ascertain which communities may play a role in the remediation process, the present study investigates the microbial community structure and diversity of microorganisms found in a full-scale membrane bioreactor (MBR) for industrial wastewater treatment. The study was carried out using high-throughput data observations following a failure (crash) of the MBR and during the extended recovery of the process. Results revealed a positive correlation between the MBR's ability to remove organic matter and its microbial community richness. The significant changes in relative microbial abundance between crash and recovery periods of the MBR revealed the important role of specific bacterial genera in wastewater treatment processes. A whole-genome metagenomics based comparison showed a clear difference in microbial makeup between two functional periods of MBR activity. The crash period was characterized by abundance in bacteria belonging to Achromobacter, Acinetobacter, Halomonas, Pseudomonas and an uncultured MBAE14. The recovery period on the other hand was characterized by Aquamicrobium and by Wenzhouxiangella marina. Our study also revealed some interesting functional pathways characterizing the microbial communities from the two periods of bioreactor function, such as Nitrate and Sulfate reduction pathways. These differences indicate the connection between the bacterial diversity of the MBR and its efficiency to remove TOC.
Journal of Scientific & Industrial Research · 2020
Omprakash Sahu
Results in Engineering · 2019