Search results for "microbial"

Using Matlab's wavelet toolbox to compare electric signals outputted by microbial fuel cells

2019

Motivation: microbial fuel cells (MFC) represents a wastewater treatment technology with the potential for a relevant electric energy generation. The monitoring of the electric current outputted generates time series of data. It was generated two time series using an experimental setup with a low-cost dual chamber microbial fuel cell treating cassava wastewater and, also, it was used the electric current data from a previously described experiment with this same setup treating cheese whey. All of this, innovatively, according our best knowledge, was studied using power spectral density, multifractal and wavelet coherence analysis. Results are promising and indeed point out this approach as …

Effect of sludge age on microbial consortia developed in MFCs

2017

BACKGROUND This work is focused on the assessment of the performance of mini-scale air-breathing microbial fuel cells (MFCs), by monitoring the evolution of the bio-electrogenic activity for a period of 40 days and by comparing the microorganisms populations developed in each of the MFC after this period. RESULTS Five MFCs were operated at sludge ages ranging from 1.4 to 10.0 days. Results showed the superb performance of the MFC operating under a sludge age of 2.5 days. Desulfuromonas, Syntrophothermus, Solitalea, Acholeplasma, Propionicimonas, Desulfobacula and Sphaerochaeta are proposed as potential responsible for the bio-electrogenic activity. CONCLUSIONS Microbial population analysis …

Development of a module of stacks of air-breathing microbial fuel cells to light-up a strip of LEDs

2018

Abstract This work focuses on scaling-up of the microbial fuel cells technology according to the principle of miniaturization and multiplication. Seven stacks of 16 mini-MFCs (electrodic area of 0.866 cm2) were built up leading to a big module of 112 MFCs. The electrical connection among the MFCs in the stacks and among the stacks into the modules was optimized in order to implement this technology. Results show that 1 MFC generates 1.22 mW while the optimization of the electric connection in order to achieve the maximum power results in 6.62 mW compared to the theoretical 182 mW, indicating the existence of large energy losses in the system. However, to light a LED there is not a threshold…

On the staking of miniaturized air-breathing microbial fuel cells

2018

Abstract This work focuses on the scale-up of the MFCs by miniaturization and multiplication strategy. Performances of five stacks containing 1, 2, 5, 8 and 16 MFCs were compared. Each stack was evaluated under individual, parallel and series electrical connection as well as for cascade or individual hydraulic connection. Cascade feeding mode with a tank per stack favours the COD removal when the number of MFCs in the stack increases. However, despite operating without COD limitations, the energy production was disadvantaged. By changing the feeding system of a tank per stack into an individual tank per MFC, the performance of the whole stack enhances considerably. Stacking in series can in…

A single-chamber membraneless microbial fuel cell exposed to air using Shewanella putrefaciens

2016

Abstract Microbial Fuel Cells (MFCs) are bio-electrochemical devices which convert the chemical energy content of organic fuels into electricity, thanks to the ability of anode respiring bacteria to give electrons to the anode. This result is usually achieved under anaerobic conditions, obtained with a sealed anode chamber. Despite this, Shewanella oneidensis has been recognized by many authors to obtain the same results in presence of air. Furthermore, another member of the Pseudomonaceae family, Shewanella putrefaciens, has also shown the capability to catalyze the cathodic oxygen reduction. In this work the capability of S. putrefaciens to work under both anaerobic and micro-aerobic cond…

Possibility of Wastewater Treatment Using MFC with Ni-Co Catalyst of Fuel Electrode

2016

Abstract One of the problems with microbial fuel cells is a low current density of those energy sources. Nonetheless, it is possible to increase the current density by using the catalyst for fuel electrode (anode) - as long as a low cost catalyst can be found. The possibility of wastewater treatment using the Ni-Co alloy as catalyst for MFC’s is presented in this paper. The alloys were obtained with different concentrations of Co (15 and 50% of Co). The increase of current density with Ni-Co catalyst is approximately 0,1 mA/cm2. So, a fundamental possibility wastewater treatment using the Ni-Co alloy as catalyst for microbial fuel cells was presented.

Optimization of the performance of an air-cathode MFC by changing solid retention time

2017

Experimental Evaluation of a New Thermal Process for Microorganisms Inactivation

2015

A new thermal process for the inactivation of microorganisms in beverages has been studied and is presented in this paper. The treatment, not yet studied in the scientific literature, mainly consists of a thermal shock characterized by temperature increases up to 30°C/s, with final temperatures up to 65°C. This study presents the first experimental results obtained by the application of the new thermal treatment, with different combinations of the process parameters (rate of temperature rise, final temperature and holding time), on separate suspensions of Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Listeria innocua and Candida albicans. The required rapid temperature in…

Characterization in the archaeological excavation site of heterotrophic bacteria and fungi of deteriorated wall painting of Herculaneum in Italy

2011

Microbiological characterization of frescos in four different locations (Collegio degli Augustali, Casa del Colonnato Tuscanico, Casa dello Scheletro and Casa del Gran Portale) of excavation sites of Herculaneum was carried out. The use of infrared thermography allowed detecting sample points on frescos with greatest moisture not visible to the naked eye, resulting in structural damage. The microclimatic conditions provided perfect habitat for bacteria and fungi, particularly of spore forming and mould. In fact, heterotrophic bacteria were prevalent in all wall paintings monitored (ranging from 18 +/- 2 CFU 100 cm(-2) to 68 +/- 4 CFU 100 cm(-2)), whereas fungi were also detected but at lowe…

MODERN TECHNOLOGIES FOR CONSERVATION OF VILLA ZITO PAINTINGS COLLECTION (PALERMO – SICILY)

2017

In this study we describe the conservative integrated approach performed on 40 paintings, dating from different period (XVII- XX century), belonging to “Fondazione Sicilia “ and exposed in Villa Zito paint gallery in Palermo (Mazzocca 2015). Through a multidisciplinary approach both constitutive materials and state of conservation have been determined. Particularly, pigments and executive techniques were identified by non-invasive diagnostic investigation (XRF analysis, UV fluorescence acquisition, and IR Reflectography) as well as previous restorations events. The study has included the revealing of microbial colonization by using non-invasive sampling methods (Nylon membrane fragment) and…