scholarly journals Decentralized wastewater treatment using a bioelectrochemical system to produce methane and electricity

2016 ◽  
Vol 6 (4) ◽  
pp. 613-621
Author(s):  
Cynthia J. Castro ◽  
Varun Srinivasan ◽  
Joshua Jack ◽  
Caitlyn S. Butler

Biological electrochemical systems (BESs) have the potential for decentralized treatment in developing countries. A 46 L, two-chamber, hydraulically partitioned microbial fuel cell (MFC) was designed to replicate low-flow scenarios leaving a composting toilet. The co-evolution of electricity and methane in this MFC was evaluated by testing two distinct waste streams: synthetic feces (Case F) and municipal primary effluent (Case W). Oxidation of organic matter was 76 ± 24% during Case F and 67 ± 21% during Case W. Methanogenesis was dominant in the anode, yielding potential power of 3.3 ± 0.64 W/m3 during Case F and 0.40 ± 0.07 W/m3 during Case W. Electrical power production was marginal, Case F = 4.7 ± 0.46 and Case W = 10.6 ± 0.39 μW/m3, although potentially useful in energy-limited areas. Complimentary batch cultivations with anode inocula yielded greater methane production in the presence of graphite. 74 ± 11% more methane was produced with graphite than suspended growth enrichments and 58 ± 10% more than enrichments with non-conductive plastic beads. The co-production of methane and electricity in an MFC may have utility in decentralized treatment. Further work is needed to optimize power from both electricity and methane.

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1279
Author(s):  
Rabeay Y.A. Hassan ◽  
Ferdinando Febbraio ◽  
Silvana Andreescu

Microbial electrochemical systems are a fast emerging technology that use microorganisms to harvest the chemical energy from bioorganic materials to produce electrical power. Due to their flexibility and the wide variety of materials that can be used as a source, these devices show promise for applications in many fields including energy, environment and sensing. Microbial electrochemical systems rely on the integration of microbial cells, bioelectrochemistry, material science and electrochemical technologies to achieve effective conversion of the chemical energy stored in organic materials into electrical power. Therefore, the interaction between microorganisms and electrodes and their operation at physiological important potentials are critical for their development. This article provides an overview of the principles and applications of microbial electrochemical systems, their development status and potential for implementation in the biosensing field. It also provides a discussion of the recent developments in the selection of electrode materials to improve electron transfer using nanomaterials along with challenges for achieving practical implementation, and examples of applications in the biosensing field.


Author(s):  
J. A. Chattha ◽  
M. S. Khan ◽  
H. Iftekhar ◽  
S. Shahid

Pakistan has a hydro potential of approximately 42,000MW; however only 7,000MW is being utilized for electrical power production [1, 2]. Out of 42,000 MW, micro hydro potential is about 1,300MW [1, 2]. For typical site conditions (available flow rate and head) in Pakistan, Cross Flow Turbines (CFTs) are best suited for medium head 5–150m [3] for micro-hydro power production. The design of CFT generally includes details of; the diameter of the CFT runner, number of blades, radius of curvature and diameter ratio. This paper discusses the design of various CFTs for typical Pakistan site conditions in order to standardize the design of CFTs based on efficiency that is best suited for a given site conditions. The turbine efficiency as a function of specific speed will provide a guide for cross flow turbine selection based on standardized turbine for manufacturing purposes. Standardization of CFT design will not only facilitate manufacturing of CFT based on the available site conditions with high turbine efficiency but also result in reduced manufacturing cost.


2000 ◽  
Vol 41 (3) ◽  
pp. 195-202 ◽  
Author(s):  
H. Kübler ◽  
K. Hoppenheidt ◽  
P. Hirsch ◽  
A. Kottmair ◽  
R. Nimmrichter ◽  
...  

Operational results of a co-digestion facility were assessed over a period of 18 months. The organic fraction of municipal solid waste (OFMSW) contains a considerable amount of contaminants and grit (up to 6% w/w). A BTA-Pulper efficiently treated the different waste streams and converted a high amount of volatile solids (VS) into the digester feedstock. The seasonal fluctuations of the waste composition significantly influenced the biogas production. The impact of this seasonally variant degradability of VS had to be considered by evaluating the operation results. The waste streams investigated did not show any negative impact on digester performance. The hydraulic retention time (HRT) in the digester considerably affected the VS-reduction. Despite a considerable decrease of VS-degradation a reduction of HRT from 14 to 8 days slightly improves the gas production rate (GPR). An activated sludge system efficiently reduced the pollution of the effluent.The nutrient content of the anaerobic compostwas favourable and the content of pollutants was low. The facility produced surplus electrical power up to 290 MJ/t. An overall energy balance shows that the facility substitutes primary energy.


2017 ◽  
Vol 79 (5-2) ◽  
Author(s):  
Zul Hasrizal Bohari ◽  
Nur Asyhikin Azhari ◽  
Nuraina Nasuha Ab Rahman ◽  
Mohamad Faizal Baharom ◽  
Mohd Hafiz Jali ◽  
...  

Energy trending lately shown the need of new possible renewable energy. This paper studies about the capability and capacity generating of electricity by using Bio-electricity-Microbial Fuel Cell (Bio-MFC). Bio-MFC is the device that converts chemical energy to electrical energy by using microbes that exist in the sewage water. The energy contained in organic matter can be converted into useful electrical power. MFC can be operated by microbes that transfer electrons from anode to cathode for generating electricity. There are two major goals in this study. The first goal is to determine the performance characteristics of MFCs in this application. Specifically we investigate the relationship between the percentages of organic matter in a sample results in higher electricity production of MFCs power by that sample. As a result, the sewage (wastewater) chosen in the second series experiment because the sewage (wastewater) also produced the highest percentage of organic matter which is around 10%. Due to these, the higher percentage of organic matter corresponds to higher electricity production. The second goal is to determine the condition under which MFC work most efficiently to generating electricity. After get the best result of the combination for the electrode, which is combination of zinc and copper (900mV),the third series of experiments was coducted, that show the independent variable was in the ambient temperature. The reasons of these observations will be explained throughout the paper. The study proved that the electricity production of MFC can be increased by selecting the right condition of sample type, temperature and type of electrode. 


2019 ◽  
Vol 7 (2) ◽  
pp. 38-46
Author(s):  
Hayder H. Abbas ◽  
Fakhri H. Ibraheem ◽  
Ahmed A. Maaroof

Koya city, like any other city in the world, faces a critical environmental problem which is global warming and the increase in the rate of production of gaseous pollutants. This research is involved with the negative effects of private Electrical Power Generators (EPGs) on the environment in Koya City. The environmental pollutants resulted from EPGs were investigated by performing an actual study on land for the number of (EPGs), types, and distribution. Koya city is divided into 18 quarters. The investigation covers a period from 2009 to 2017, included. The production of power was increased due to the increase in the number of generators and supplying hours. The power production in 2009 was 23,850 megawatt (MW) whereas it was 49,635 MW in 2017. The amount of fuel consumed in 2009–2017 was relatively increased from 30,000 to 62,500 barrel/year. The total amount of pollutants was increased by about 108% during the period 2009–2017. The results showed that the most significant increase in pollutants was carbon dioxide (CO2). The annual amount of (CO2) emitted in 2009 was 6588 tons whereas it has increased in 2017–13710 tons. The conclusion of this study was that the highest pollution occurred in the center of Koya City in Nabeel quarter, which represented 22% of the whole pollutants.


Energy ◽  
2012 ◽  
Vol 45 (1) ◽  
pp. 62-70 ◽  
Author(s):  
Stanisław Sieniutycz ◽  
Artur Poświata

Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 740 ◽  
Author(s):  
Jesus L. Lobo ◽  
Igor Ballesteros ◽  
Izaskun Oregi ◽  
Javier Del Ser ◽  
Sancho Salcedo-Sanz

The prediction of electrical power produced in combined cycle power plants is a key challenge in the electrical power and energy systems field. This power production can vary depending on environmental variables, such as temperature, pressure, and humidity. Thus, the business problem is how to predict the power production as a function of these environmental conditions, in order to maximize the profit. The research community has solved this problem by applying Machine Learning techniques, and has managed to reduce the computational and time costs in comparison with the traditional thermodynamical analysis. Until now, this challenge has been tackled from a batch learning perspective, in which data is assumed to be at rest, and where models do not continuously integrate new information into already constructed models. We present an approach closer to the Big Data and Internet of Things paradigms, in which data are continuously arriving and where models learn incrementally, achieving significant enhancements in terms of data processing (time, memory and computational costs), and obtaining competitive performances. This work compares and examines the hourly electrical power prediction of several streaming regressors, and discusses about the best technique in terms of time processing and predictive performance to be applied on this streaming scenario.


2020 ◽  
Author(s):  
Jinpeng Liu ◽  
Harald Horn ◽  
Michael Wagner

<p>Carbon-based and stainless steel-based materials are widely utilized as anode/cathode electrodes in bio electrochemical systems (BESs) due to its low capital cost, high conductivity and large specific surface area. Carbon-based materials such as carbon veil are mostly applied in lab-scale reactors because of its versatile shape and configuration. Moreover, stainless steel type materials show higher strength and are easier to incorporate within flow field. Optical coherence tomography (OCT) as an image technique is a suitable method to monitor biofilm growth and fluid-structure interactions at the meso-scale. In BESs, investigating bulk-biofilm interface (fluid-structure interactions) is of particular interest to optimize the mass transfer under suitable hydrodynamic condition and enhances the overall effectivity of BESs systems. To extend the knowledge about the influence of different anode electrodes as substratum on OCT monitoring and quantification, the biofilm structural properties analyzed by OCT image processing and bioelectrochemical systems performance were compared.  </p> <p>A custom-designed dual-chamber setup was constructed by two transparent optical flow cells and fixed in the automated monitoring platform (Evobot). Herein, we applied OCT to in-situ characterize and quantify the biofilm structure properties on two different anode electrodes (carbon veil-CV and porous stainless steel-SS) as substratum in microbial fuel cell (MFC) mode.  3D OCT dataset analysis presented 3 structural parameters for biofilm-carbon veil interface and 5 structural parameters for biofilm-stainless steel interface, separately. Biofilm volume (BioV) was calculated to compare CV and SS anode electrodes.</p> <p>In this study, a time-series of biofilm development was performed on both CV and SS materials. At the fourth day, the biofilm almost covered the entire anode surface and achieved 97% substratum coverage. Afterwards the biofilm grew mostly in vertical direction. With the further biofilm growth along height the electric resistance increased and power production gradually reached the equilibrium. Nevertheless, both materials did not show predominant advantage on power production. Furthermore, a relatively small error appeared on quantitative analysis of Biofilm volume using stainless steel. Whereas, the predictability of biofilm volume on the carbon veil anodes was hindered by the appearance of shadowing effects. Thus, it can be concluded that stainless steel flat plate electrode is preferable as anode material to investigate the interaction between biofilm structure, hydrodynamic conditions and mass transfer in BESs via OCT.</p>


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