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Feeding a Membrane-less Microbial Fuel Cell by Mixed Municipal and Industrial Wastewater

Włodarczyk Barbara, Włodarczyk Paweł P.

Civil and Environmental Engineering Reports

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2023

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Vol. 33, no. 4

50--62

EN

Due to the constant growth of the world's population, the amount of generated wastewater is also constantly increasing. One of the devices that can use wastewater as a raw material for energy production is a microbial fuel cell (MFC). MFCs technology is constantly evolving. However, to increase its use, it is necessary to improve its efficiency. There are various possibilities to ensure this, such as the use of new electrode materials, new cell designs, or the use of wastewaters from different sources. In this paper the analysis of MFC operation (cell voltage, power, and current density) fed by mixed municipal and industrial wastewaters was shown. Moreover, the change in time of COD was analyzed. Due to cost reduction the membrane-less microbial fuel cell (ML-MFC) was chosen. It was noted that the addition of concentrated process wastewater increases the COD reduction time in the ML MFC. An increase of generated bioelectricity during fed ML-MFC by mixed municipal and industrial (process wastewater from yeast production) wastewater was demonstrated. The highest values of average cell voltage (598 mV), maximum power (4.47 mW) and maximum current density (0.26 mA•cm-2) were obtained for a 10% share of yeast process wastewater in the mixed wastewater, which fed the ML-MFC.

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Effect of Using Various Cathode Materials (Carbon Felt, Ni-Co, Cu-B, and Cu-Ag) on the Operation of Microbial Fuel Cell

Włodarczyk Paweł P., Włodarczyk Barbara

Civil and Environmental Engineering Reports

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2023

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Vol. 33, no. 4

95--105

EN

Wastewater has high potential as an energy source. Therefore, it is important to recover even the smallest part of this energy, e.g., in microbial fuel cells (MFCs). The obtained electricity production depends on the process rate of the electrodes. In MFC, the microorganisms are the catalyst of anode, and the cathode is usually made of carbon material. To increase the MFC efficiency it is necessary to search the new cathode materials. In this work, the electricity production from yeast wastewater in membrane-less microbial fuel cells with a carbon felt, Ni-Co, Cu-B, and Cu-Ag cathodes has been analyzed. In the first place, the measurements of the stationary potential of the electrodes (with Cu-Ag catalyst obtained by the electrochemical deposition technique) were performed. Next, the analysis of the electric energy production during the operation of the membrane-less microbial fuel cell (ML-MFC). The highest parameters were obtained for the Ni-Co and Cu-Ag catalysts. The cell voltage of 607 mV for Ni-Co and 605 mV for Cu-Ag was obtained. Additionally, the power of 4.29 mW for both cathodes - Ni-Co and Cu-Ag was obtained. Moreover, Ni-Co and Cu-Ag allow the shortest time of COD reduction. Based on the test results (with selected MFC design, wastewater, temperature, etc.), it can be concluded that of all the analyzed electrodes, Cu-Ag and Ni-Co electrodes have the best parameters for use as cathodes in ML-MFC. However, based on the results of this study, it can be concluded that all the tested electrodes can be used as cathode material in MFC.

3

An attempt to apply fenton system in wastewater pretreatment from acetazolamide production

Rauckyte T., Żak S.

Chemia i Inżynieria Ekologiczna

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2006

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Vol. 13, nr 10

1133-1141

EN

The research was made on the possibility of pretreating wastewater from acetazolamide (2-acctyloaminc-1,3,4-thiadiazolc-5-sulphonamidc) production with the use of deep oxidation by the application of Fenton mixture. Optimal range of the reaction (pH), concentrations of iron(II) salts and hydrogen peroxide as well as their mutual molar proportions for which maximal COD reductions occurred were determined. Changes in the relations BOD5/COD, COD/N and BOD5/N were determined. It was found that the application of Fenton system significantly reduced COD and total suspended solids and eliminated color completely. The level of COD load depended on the quantity and the mutual proportions COD:Fe(II):H2O2. A high repeatability of the results and COD reduction more than 60 % were obtained for iron concentrations 500-2000 mg/dm3 with molar surplus of [H2O2] :[Fe(II)] - 2-10:1 and the reaction pH = 2.5-3.5. Within this range of reagents' concentrations, the distribution of COD reduction values correlated with the equation: COD = Ax3 - Bx2 + Cx - D(where: x=[H2O2] :[Fe(II)]). The method helped us consider possibilities of chemical pretreatment of wastewater from acetazolamide production and then a complete biological treatment by conventional methods.

PL

Przeprowadzono badania nad możliwością podczyszczania ścieków z produkcji acetazolamidu (2-acctylo-amino-1,3,4-tiadiazo-5-sulfonamid) z zastosowaniem głębokiego utleniania za pomocą mieszaniny Fentona. Wyznaczono optymalny zakres odczynu pH, stężeń soli żelaza(II) oraz nadtlenku wodoru, a także ich wzajemne proporcje molowe, dla których zachodziły maksymalne redukcje ładunku ChZT. Określono zamiany relacji BZT5/ChZT oraz ChZT/N i BZT5/N. Stwierdzono, że zastosowanie układu Fentona pozwala na dużą redukcję ChZT i zawiesin ogółem oraz pełną eliminację barwy. Poziom redukcji ładunku ChZT zależy od ilości i wzajemnych proporcji ChZT : Fe(II) : H202. Dla stężeń żelaza 500-2000 mg/dm3 przy nadmiarze molowym [H2O2] :[Fe(II)) - 2-10:1 i odczynie pH = 2.5-3.5 uzyskano bardzo dobrą powtarzalność wyników oraz redukcję ChZT, przekraczającą 60 %. W tym zakresie stężeń reagentów rozkład wartości redukcji ChZT korelował z równaniem postaci ChZT = Ax3 - Bx2 + Cx - D (gdzie: x=[H2O2] :[Fe(II)]). Metoda pozwala na rozwalenie możliwości wstępnego chemicznego podczyszczania ścieków z produkcji acetazolamidu a następnie pełnego biologicznego oczyszczania metodami konwencjonalnymi.