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1

Optimization and performance evaluation of microbial fuel cell by varying agar concentration using different salts in salt bridge medium

Singh K., Dharmendra

Archives of Materials Science and Engineering

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2020

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Vol. 101, nr 2

79--84

EN

Purpose: Comparative study of various agar-agar (C14H24O9) percentage and different salts concentration in the salt bridge is carried out to check the efficiency of microbial fuel cell. Design/methodology/approach: Dual chambered microbial fuel cell was used for the overall experiments. Anode and cathode chambers were made of 500 ml plastic jar. Salt bridge was fabricated with agar-agar technical and 3 M NaCl in a PVC pipe of 2 cm long. Chemical Oxygen Demand, pH and electrical conductivity of wastewater were examined. Oxygen was supplied in the cathode chamber using the aquarium pump. Voltage (open circuit voltage) was observed using digital multimeter. Graphite rods were used as anode and cathode electrodes. Findings: Salt bridge was constructed of 3 M NaCl with 5, 7.5, 10 and 12 percent variation of agar amounts in MFC. The maximum outputs were observed 301, 306, 325 and 337.25 mV with the variation of agar 5, 7.5, 10 and 12 percentages respectively as well as chemical oxygen demand (COD) removal efficiency was observed 47.92, 56.25, 52.08 and 64.58 percentages respectively. The optimum agar concentration was found to be 12 percent and a maximum voltage of 337.25 mV and COD removal of 64.58 percent was achieved. After the optimization of agar percentage two salts i.e., Sodium chloride and potassium chloride were analysed. This study also reveals that the NaCl salt bridge is more efficient than KCl salt bridge for the same agar concentration. The maximum voltage for NaCl and KCl were 319 and 312 mV respectively. Research limitations/implications: The amount of electricity production is low and field scale implementation is difficult using microbial fuel cell. The research is still on progress in this field. Originality/value: here is very little research with salt bridge and MFC. Comparative study of different mole of salt is available but agar variation is not yet studied.

2

Fabrication of Agar-Silica Aerogel Nanocomposite Films

Lee Min-Jin, Jung Hyun-Ah, Lee Kyong-Jin, Hwang Haejin

Archives of Metallurgy and Materials

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2019

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Vol. 64, iss. 3

851--855

EN

In this study, agar-based nanocomposite films containing ultra-porous silica aerogel particles were fabricated by gel casting using an aqueous agar/silica aerogel slurry. The silica aerogel particles did not show significant agglomeration and were homogeneously distributed in the agar matrix. Transmission electron microscopy observations demonstrated that the silica aerogel particles had a mesoporous microstructure and their pores were not incorporated into the agar polymer molecules. The thermal conductivities of the agar and agar/5wt.% silica aerogel nanocomposite films were 0.36 and 0.20 W·m-1·K-1, respectively. The transmittance of the agar films did not decrease upon the addition of silica aerogel particles into them. This can be attributed to the anti-reflection effect of silica aerogel particles.

3

Immobilization of Lycinibacillus fusiformis B26 cells in different matrices for use in turquoise blue HFG decolourization

Dogan N. M., Sensoy T., Doganli G. A., Bozbeyoglu N. N., Arar D., Akdogan H. A., Canpolat M.

Archives of Environmental Protection

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2016

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Vol. 42, no. 2

92--99

EN

The decolourization of Turquoise Blue HFG by immobilized cells of Lysinibacillus fusiformis B26 was investigated. Cells of L. fusiformis B26 were immobilized by entrapment in agar and calcium alginate matrices and attached in pumice particles. The effects of operational conditions (e.g., agar concentrations, cell concentrations, temperature, and inoculum amount) on microbial decolourization by immobilized cells were investigated. The results revealed that alginate was proven to be the best as exhibiting maximum decolourization (69.62%), followed by agar (55.55%) at 40°C. Pumice particles were the poorest. Optimum conditions for agar matrix were found: concentration was 3%, cell amount was 0.5 g and temperature was 40°C (55.55%). Ca-alginate beads were loaded with 0.5, 1.0 and 2.0 g of wet cell pellets and the highest colour removal activity was observed with 2.0 g of cell pellet at 40°C for alginate beads. Also, 0.5 and 1.0 g of pumice particles that were loaded with 0.25 and 0.5 g of cell pellets respectively were used and the results were found very similar to each other.

4

Algi – przyszłość z morza

Kępska D, Olejnik Ł.

Chemik

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2014

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Vol. 68, nr 11

967--972

PL

Algi są organizmami fotosyntetyzującymi, prokariotycznymi albo eukariotycznymi. Ich komórki zawierają aminokwasy, witaminy, składniki mineralne, NNKT, aosainę,polifenole, kwasy o silnym działaniu nawilżającym i pobudzające krążenie krwi polisacharydy, a także β- karoten i karotenoidy. Ze względu na swój bogaty skład chemiczny, biomasa glonów znalazła zastosowanie w przemyśle spożywczym, farmaceutycznym i kosmetycznym. Preparaty z alg, stosowane jako suplementy diety i składniki środków upiększających, cechuje wysoka czystość chemiczna i efektywność działania. Do najlepiej poznanych polisacharydów alg należą: agar oraz alginian. Ponadto, prowadzone są badania dotyczące zastosowania alg jako źródła alternatywnej energii w postaci biopaliw, a także w procesie oczyszczania ścieków.

EN

Algae are photosynthetic prokaryotic or eukaryotic organisms. Their cells contain amino acids, vitamins, minerals, essential fatty acids, aosain, polyphenols, a potent moisturizing acids, polysaccharides, which are stimulating blood circulation, β-carotene and carotenoids. With such a rich chemical composition, biomass of algae has been used in food, pharmaceutical and cosmetic industries. Preparations of algae used as dietary supplements and beauty measures are characterized by high chemical purity and effectiveness. The best known algal polysaccharides are: agar and alginate. In addition, there is a research conducted on the use of algae as an alternative source of energy in the form of biofuels as well as in waste water treatment.

5

Changes of some Selected Soil Properties Incubated with the Addition of Agar, Starch and Effective Microorganisms

Jakubus M., Kaczmarek Z., Wolna-Maruwka A.

Ecological Chemistry and Engineering. A

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2012

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Vol. 19, nr 1-2

61-68

EN

From among increasing numbers of various ecological solutions which are applied in traditional farming, considerable usefulness of the Effective Microorganism (EM) technology is frequently indicated. This preparation is believed to exhibit a wide spectrum of activities both in plant as well as in animal production. It has been demonstrated that after soil application of the discussed preparation, mineralisation and humification processes of organic compounds are accelerated. Possible changes in soil chemical properties which could occur following the application of this conditioner continue to remain debatable. In the light of the above, investigations were undertaken with the aim to determine the impact of EM on selected physicochemical and chemical soil properties. The above tasks were realised with the assistance of an incubation experiment employing Phaeozems inoculated with EM to which increasing doses of agar or starch were added. The obtained data revealed that the application of EM with polysaccharides can exert different effects on the examined soil properties. No statistically significant influence was observed with regards to the majority of the examined physicochemical properties. Quantitative changes of macro- and microelements depended on the type of the applied polysaccharide and its dose.

PL

Wśród różnych rozwiązań ekologicznych mających zastosowanie w tradycyjnym rolnictwie wskazuje się na dużą przydatność technologii Efektywnych Mikroorganizmów (EM). Preparatowi temu przypisuje się szerokie spektrum działania tak w produkcji roślinnej, jak i zwierzęcej. Wykazuje się, że po zastosowaniu doglebowym omawianego preparatu następuje przyspieszenie procesów mineralizacyjno-humifikacyjnych związków organicznych. Dyskusyjną kwestią są zmiany we właściwościach chemicznych gleb, jakie mogłyby nastąpić w konsekwencji oddziaływania tego kondycjonera. W związku z powyższym podjęto badania mające na celu określenie wpływu EM na wybrane właściwości fizykochemiczne i chemiczne gleb. Realizacji tego zadania dokonano w oparciu o doświadczenie inkubacyjne z glebą czarna ziemia właściwą zaszczepioną EM, do której dodawano wzrastające dawki agaru lub skrobi. Uzyskane dane świadczą o różnym wpływie EM z polisacharydami na badane właściwości gleby. W odniesieniu do większości badanych właściwości fizykochemicznych nie stwierdzono oddziaływania istotnego statystycznie. Zmiany ilościowe makro- i mikroskładników były uzależnione od rodzaju polisacharydu oraz jego dawki.

6

Wpływ gumy guar na właściwości reologiczne żeli agaru

Różański J.

Inżynieria i Aparatura Chemiczna

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2009

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Nr 4

110-111

PL

W pracy przedstawiono wyniki badań Teologicznych dla żeli agaru i mieszanek agaru z gumą guar w przepływie ścinającym i oscylacyjnym. Zaobserwowano, że żele, w których agar był częściowo zastąpiony przez gumę guar charakteryzowały się niższą temperaturą żelowania i wyższą temperaturą rozpuszczania. Wyniki badań uzyskane w pomiarach oscylacyjnych wskazują, że dodatek gumy guar do roztworu agaru powoduje wzrost modułu sprężystości.

EN

Rheological research results dealing with agar ge)s and mixtures of gar and guar gum in shear and osciHatory flow arę presented in the paper. It was observed that gels in which agar was partially substituted by guar gum were characterized by the lower gelling temperature and higher dissolving temperature. The results obtained using osciHatory measurements indicate that the guar gum addition to agar solution causes the increase of elastic modulus of viscoelastic properties.

7

Method for Evaluating Germicidal Ultraviolet Inactivation of Biocontaminated Surfaces

Gorsuch E. L., Grinshpun S. A., Willeke K., Reponen T., Moss C. E., Jensen P. A.

International Journal of Occupational Safety and Ergonomics

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1998

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Vol. 4, No. 3

287--297

EN

Safety issues related to work-site conditions often deal with potential worker exposure to infectious airborne microorganisms due to their dissemination in indoor air and contamination of surfaces. Germicidal ultraviolet (GUV) radiation is used in health-care settings and other occupational environments for microbial inactivation. In this study, a new methodology for determining the efficiency of GUV microbial inactivation of surfaces was developed and evaluated. The method utilizes identical chambers in which test microorganisms are irradiated on agar surfaces at different humidity and irradiation intensity levels. The effects of GUV intensity and exposure time on microbial inactivation were examined for Micrococcus luteus and Serratia marcescens. It was found that at low humidity levels (20-25%) both organisms can be inactivated with at least 95% efficiency if the GUV intensity exceeds 50 /zW/cm2 for at least 3-5 min (corresponding to a dose of ~ 1 0 mJ/cm2). The radiation dose needed for effective inactivation of S. marcescens, as measured by a UV meter near the microbial sample, was found not to be affected by the humidity level, whereas that of M. luteus increased at higher humidities. The findings of this study can be used to determine sufficient GUV inactivation doses for occupational environments with various microbial contaminations.