Sharif Digital Repository

The objective of present study is to analyze the dynamic modeling of bioelectrochemical processes and improvement of the performance of previous models using quantitative data of bacterial transport parameters. The main deficiency of previous MFC models concerning spatial distribution of biocatalysts is an assumption of initial distribution of attached/suspended bacteria on electrode or in anolyte bulk which is the foundation for biofilm formation. In order to modify this imperfection, the quantification of chemotactic motility to understand the mechanisms of the suspended microorganisms’ distribution in anolyte and/or their attachment to anode surface to extend the biofilm is implemented... 

The present study investigates the diversification and dynamic behavior of a multi-population microfluidic microbial fuel cell (MFC) as a biosensor. The cost effective microfluidic MFC coupled to a comprehensive model, presents a novel platform for monitoring chemical and biological phenomena. The importance of competition among different microbial groups, hierarchical biochemical processes, bacterial chemotaxis and different mechanisms of electron transfer were significant considerations in the present model. The validation of the model using experimental data from a microfluidic MFC shows an appropriate match with the hierarchal biodegradation processes of a complex substrate as well as... 

The anionic surfactant linear alkylbenzene sulfonate (LAS) is a major chemical constituent of detergent formulation. Regarding the recalcitrant nature of sulfonoaromatic compounds, discharging these substances into wastewater collection systems is a real environmental issue. A study on LAS biodegradation based on bioelectrochemical treatment and in the form of developing a single-chamber microbial fuel cell with air cathode is reported in the present work. Pretreatment study showed LAS concentration of 60 ppm resulted in the highest anaerobic LAS removal of 57%; so, this concentration was chosen to run the MFC. After the sustained anodic biofilm was formed, LAS degradation rate during 4 days... 

Linear alkylbenzene sulfonate (LAS), one of the most widely used synthetic surfactants in laundry detergent industry, is considered a hazardous contaminant in wastewater. In the present study, a microbial fuel cell (MFC) based biosensor is developed to quantitively determine the LAS concentration in wastewater. To do so, the developed MFC is fed with LAS concentration of 60 mg l−1. Finally, a sustained biofilm is formed after almost 34 days and the highest open circuit potential of 425 mV is recorded. The maximum power and current densities of 75 mW m−3 and 663 mA m−3 are obtained, respectively; and the internal resistance of the MFC-based biosensor is calculated to be about 1 kΩ. After 98... 

This study reports the fabrication of a microfluidic microbial fuel cell (MFC) using nickel as a novel alternative for conventional electrodes and a non-phatogenic strain of Escherichia coli as the biocatalyst. The feasibility of a microfluidic MFC as an efficient power generator for production of bioelectricity from glucose and urea as organic substrates in human blood and urine for implantable medical devices (IMDs) was investigated. A maximum open circuit potential of 459mV was achieved for the batch-fed microfluidic MFC. During continuous mode operation, a maximum power density of 104Wm-3 was obtained with nutrient broth. For the glucose-fed microfluidic MFC, the maximum power density of... 

The present study deals with the feasibility of a microfluidic microbial electrolysis cell (MEC) as an efficient biohydrogen generator for medical usage for the first time. The evaluation of nickel in microfluidic MEC as an alternative for conventional electrodes indicates successful performance in the improvement of bioenergy production. The maximum biohydrogen production rate and produced power density of 2.2 μW cm−2 and 1.4 μl H2 μl substrate−1 day−1 were obtained, respectively. It is considered a promising technology for medical usage due to the following factors: significant biohydrogen generation, low consumption of expensive materials, simple construction, and utilization of human... 

In this study, a new model of microbial fuel cell (MFC) was obtained for the first time. The modeled MFC was made using a combination of two approaches; the conduction-based method and two-step anaerobic digestion. Performance of the MFC was based on calculations for current evolution and polarization curves with different subsequent variables of the biofilm and anolyte. The model was able to make predictions for performance of the MFC for a simple substrate to more complex ones. The model was successfully validated with a variety of substrates (acetate, glucose and dairy wastewater) and the results were compared with previously published measurements. The model polarization results showed... 

In the present study, an attempt was made to investigate the potential of some of the major world’s crops, including wheat, corn, rice, barley, sugarcane, sugar beet, potatoes, and oats, to produce biohydrogen. The collectable amount of agricultural residues that could especially be used to produce hydrogen was estimated in Africa, Asia, Central America, Europe, Northern America, Oceania, and South America, and the potential amount of ammonia as the main nitrogen fertilizer was estimated. Double exponential smoothing method was employed to forecast the future crop production and area harvested. It was calculated that about 10.56 (in 2013) and 15.5 (in 2030) Mt of biohydrogen and 59.84 (in... 

In the present study, an attempt was made to investigate the potential of some of the major world’s crops, including wheat, corn, rice, barley, sugarcane, sugar beet, potatoes, and oats, to produce biohydrogen. The collectable amount of agricultural residues that could especially be used to produce hydrogen was estimated in Africa, Asia, Central America, Europe, Northern America, Oceania, and South America, and the potential amount of ammonia as the main nitrogen fertilizer was estimated. Double exponential smoothing method was employed to forecast the future crop production and area harvested. It was calculated that about 10.56 (in 2013) and 15.5 (in 2030) Mt of biohydrogen and 59.84 (in... 

In the present study, an attempt was made to investigate the potential of some of the major world’s crops, including wheat, corn, rice, barley, sugarcane, sugar beet, potatoes, and oats, to produce biohydrogen. The collectable amount of agricultural residues that could especially be used to produce hydrogen was estimated in Africa, Asia, Central America, Europe, Northern America, Oceania, and South America, and the potential amount of ammonia as the main nitrogen fertilizer was estimated. Double exponential smoothing method was employed to forecast the future crop production and area harvested. It was calculated that about 10.56 (in 2013) and 15.5 (in 2030) Mt of biohydrogen and 59.84 (in... 

The present study investigated the biological treatment of produced water in a microbial electrochemical cell (MXC). The main objectives were to develop a novel spiral microbial electrochemical cell (SMXC) and test its performance for produced water treatment under highly saline conditions (salinity > 200000 ppm). The bioelectrochemical performance of the system was also evaluated in terms of power and hydrogen production over time. The comparatively inexpensive material and ease of application increased the feasibility of the SMXC configuration for produced water treatment. Optimal SMXC performance as a microbial fuel cell was achieved at a maximum open circuit potential of 330 mV, maximum... 

This study develops a photosynthetic microalgae microbial fuel cell (PMMFC) engaged Chlorella vulgaris microalgae to investigate effect of light intensities and illumination regimes on simultaneous production of bioelectricity, biomass and wastewater treatment. The performance of the system under different light intensity (3500, 5000, 7000 and 10,000 lx) and light/dark regimes (24/00, 12/12, 16/8 h) was investigated. The optimum light intensity and light/dark regimes for achieving maximum yield of PMMFC were obtained. The maximum power density of 126 mW m−3, the coulombic efficiency of 78% and COD removal of 5.47% were achieved. The maximum biomass concentration of 4 g l−1 (or biomass yield... 

A successful design, previously adapted for treatment of complex wastewaters in a microbial fuel cell (MFC), was used to fabricate two MFCs, with a few changes for cost reduction and ease of construction. Performance and electrochemical characteristics of MFCs were evaluated in different environmental conditions (in complete darkness and presence of light), and different flow patterns of batch and continuous in four hydraulic retention times from 8 to 30h. Changes in chemical oxygen demand, and nitrate and phosphate concentrations were evaluated. In contrast to the microbial fuel cell operated in darkness (D-MFC) with a stable open circuit voltage of 700mV, presence of light led to growth of... 

In this research, different coating methods of polyaniline (PANI) on the anode electrodes and their performance in microbial fuel cells (MFCs) were investigated. The performance of systems in a discontinuous state was studied using the high energy content dairy industry wastewater. The phase enrichment assessment was conducted under open circuit potential (OCP) and the performance of MFCs coated with PANI through three methods was evaluated via chemical oxygen demand (COD), polarization, power density, energy coulombic efficiency (ECE), coulombic efficiency (CE), and potential efficiency (PE) values. The results showed the maximum value for the power density of 28Wm-3, CE of 17%, and COD of... 

This study reports the fabrication of a new cathode electrode assembly using polyaniline (PANI) and graphene on a stainless steel mesh (SSM) as an alternative for the conventional expensive cathode of microbial electrolysis cells (MECs). With respect to the previous efforts to propose an efficient and cost-effective alternative for platinum (Pt) catalysts and cathode electrodes, the present study investigates the assessment of different catalysts to elucidate the potential of the modified SSM cathode electrode for larger-scale MECs. In the case of feeding dairy wastewater to the MEC, the maximum hydrogen production rate and COD removal were obtained by SSM/PANI/graphene cathode and had the... 

The present study investigated the capability of coupled microfluidic microbial electrolysis cell-microbial fuel cell (MEC-MFC) to remove oxalate as a toxic end-metabolite and produce hydrogen as an effective antioxidant without any external power. The modification of the system to enhance the hydrogen generation and reduce the number of microfluidic MFCs supporting the external power supply of the microfluidic MEC was implemented by using zinc anode and inoculation of Shewanella oneidensis MR-1 at a simple straight microchannel. The selection of the mentioned elements resulted from the assessment of spiral and straight geometries, nanoparticle growth, and injection rates of the substrate.... 

In this study, the effect of utilization of a nanostructured nickel based material as a negative electrode on the performance of microfluidic microbial fuel cell (MFC) with Escherichia coli as biocatalyst has been investigated. Designing the microfluidic MFC with nickel nanostructure resulted in a higher volumetric power density of 343 W m−3 compared to the previously published results. The assessment of effective parameters on the electrochemical performance of cell was investigated. The investigation of the hydraulic diameter impact on the power generation proves that reducing the microchannel hydraulic diameter from 1000 to 350 μm minimized the internal mass-transfer resistance, and...