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1

Factors Affecting the Performance of Double Chamber Microbial Fuel Cell for Simultaneous Wastewater Treatment and Power Generation

100%

Khan M. R., Amin M. S. A., Rahman M. T., Akbar F., Ferdaus K.

Polish Journal of Chemical Technology

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2013

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vol. 15

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issue 1

7-11

EN

Electricity generation from the readily biodegradable organic substrate (glucose) accompanied by decolorization of azo dye was investigated using a two-chamber microbial fuel cell (MFC). Batch experiments were conducted to study the effect of dye and substrate concentration on MFC performance. Electricity generation was not significantly affected by the azo dye at 300 mg/L, while higher concentrations inhibited electricity generation. The chemical oxygen demand (COD) removal and decolorization of dye containing wastewater used in the MFC were studied at optimum operation conditions in anode and cathode, 57% COD removal and 70% dye removal were achieved. This study also demonstrated the effect of different catholyte solutions, such as KMnO4 and K2Cr2O7 on electricity generation. As a result, KMnO4 solution showed the maximum electricity generation due to its higher standard reduction potential.

2

Biosorption of toxic metals using freely suspended Microcystis aeruginosa biomass

88%

Rzymski P., Niedzielski P., Karczewski J., Poniedziałek B.

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issue 12

1232-1238

EN

This paper describes the potential application of a freely suspended cyanobacterial biomass of Microcystis aeruginosa as a sorption material for toxic metals, cadmium (Cd) and lead (Pb) from aqueous solutions. In order to identify the most suitable conditions for removal of these elements (concentration range: 1–20 mg L−1), the laboratory experiments were carried out during different incubation times (1–48 h) and under various temperatures (10–40°C), pH (5–9) and with or without light irradiance. Competitive biosorption of Cd and Pb was also investigated. We found that M. aeruginosa demonstrates high efficiency in removing both of the studied metals from aqueous solutions. Sorption of Pb occurred, however, more rapidly and effectively, and was less disturbed by changes in physico-chemical conditions. Under pH=7, 25°C and light, the removal rates after 3 h and 6 h of incubation, were 90–100% for Pb and 79.5–100% for Cd, respectively. The co-occurrence of the metals decreased the rate of metal biosorption. Pb was sequestered preferentially over Cd. From the results we conclude that freely suspended M. aeruginosa can constitute a promising low-cost, easy-producible biosorbent material for toxic metals in contaminated wastewater.

3

A silica gel-bound macrocycle system for the selective separation of toxic cadmium from metal-affluent aqueous matrix

88%

Hasegawa H., Rahman I., Begum Z., Umehara Y., Maki T., Furusho Y., Mizutani S.

Open Chemistry

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2013

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vol. 11

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issue 3

341-347

EN

Abstract Selective separation of cadmium(II) on a macrocycle immobilized solid phase extraction (SPE) system namely AnaLig Cd-01, and commonly known as molecular recognition technology (MRT) gel, have been examined. The MRT-SPE able to retain the cadmium from the metal-affluent aqueous matrix at the pH range of 2 to 8, and the captured species can be recovered via elution with 1 and 6 M HNO3. Besides the effects of solution pH and eluent concentration, the impacts of sample loading flow rates and coexisting matrix ions were also investigated and optimized. The Cd(II) retention capacity of the MRT-SPE was 0.26 mmol g-1, and it can be reused for more than 100 loading and elution cycles. The Cd(II) recovery attained from the metal-spiked natural waters was satisfactory (95.3–98.1%). However, the Cd(II) retention ability of the MRT-SPE was significantly decreased when excess of chelant remain in the aqueous waste matrix. Graphical abstract [...]

4

A comparison of fluorescein and deuterated water as tracers for determination of constructed wetland retention time

88%

Holcová V., Šíma J., Dušek J.

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EN

Retention time of treated water in a horizontal subsurface flow constructed wetland was determined in the non-vegetative period using fluorescein and deuterium oxide. Fluorescein served as one of the most frequent tracers detectable at extremely low concentrations by fluorimetry; however, deuterated water (concentrations of deuterium measured by IRMS and expressed as δ (‰) against VSMOW) was used to precisely simulate the treated water flow movement. Tracer retention time (TRT) of fluorescein was 194 h while deuterated water TRT was 192 h. TRT and nominal hydraulic retention time (nHRT, 190 h) were nearly exactly equal. The tracer behavior of deuterated water was almost ideal. On the other hand, the fluorescein movement through the system was slightly influenced by the interaction with the vegetation bed (sorption causing the tailing of tracer-response curves). Nevertheless, both tracers can be successfully used and provide similar results. Retention time is a very important characteristic of a constructed wetland. It is closely connected with the efficiency of the contaminant removal from treated water. It has to be determined correctly when wetland operation parameters are optimized. The choice of the suitable and reliable tracer is always necessary. Fluorescein takes preference with respect to its simple and inexpensive determination. [...]

5

Photocatalytic decolorization of methyl orange solution with potassium peroxydisulfate

88%

Junbo Z., Di M., Hong Z., An L., Jiao L., Shengtian H., Jianzhang L.

Open Chemistry

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2008

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vol. 6

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issue 2

245-252

EN

Increasing environmental pollution caused by toxic dyes due to their hazardous nature is a matter of great concern. It has been generally agreed that methyl orange (MO) can be effectively degraded in aerated K2S2O8 homogeneous reaction system using near-UV irradiation. In this paper photocatalytic degradation of MO solutions with K2S2O8 was investigated, with particular attention on the possible underlying mechanisms. This report has shown decolorization efficiency of MO increases with the increasing of the dosage of the catalyst. There is no optimal amount of catalyst in our case, where special attention was paid on the nature of the photocatalyst itself. The current research revealed that the decolorization reaction is a pseudo first-order reaction when the concentration of MO is below 20 mg L−1 and the decolorization reaction is zero-order reaction when the concentration of MO is above 100 mg L−1, but the Langmuir-Hinshewood kinetic model does not describe this. The influence of IO 4−, BrO 3− and H2O2 were investigated in detailed. Several observations indicate that the mechanism is not involved in hydroxyl radical attacks in MO degradation with K2S2O8 by UV irradiation. The possible underlying mechanisms are direct oxidation of the MO by S2O 82− and hydrogen attraction by SO 4•−. [...]

6

Extended Spectrum Beta Lactamase (ESBL) producing enteric bacteria from hospital wastewater, Ibadan, Nigeria

63%

Falodun O. I., Oladimeji O. S.

World News of Natural Sciences

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2019

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vol. 22

62-74

EN

This study was conducted to investigate the occurrence of antibiotic resistance, including β-lactamase and extended spectrum β-lactamase production among enteric bacteria isolated from hospital wastewater from selected hospital within Ibadan. Physico-chemical analysis of hospital wastewater samples was done, enteric bacteria were isolated and identified using convectional biochemical tests while the selection of potential ESBL-producing bacteria was carried out using disc diffusion method and ESBL detection using double synergy test. The turbidity of the wastewater samples ranged between 4.45-6.5 NTU and total suspended solids ranged between 3.4- 45.5 mg/L. While electrical conductivity was between114.25-214 µs/m, the biological oxygen demand was between 25.8-31.25 mg/L and chemical oxygen demand ranged between 41.25-45.38 mg/L. Of the 200 bacteria isolated 35(17.5%) produced ESBL; 14(40%) from the tertiary hospital and 21(60%) from private hospital out of which 85.7%, 80% and 65.7% showed resistance to sulphamethxazole/Trimetoprim, streptomycin and tetracycline respectively, while resistance to meropenem (8.6%) was low. Among the ESBL-producing isolates, K. pneumonia had the highest (15(42.8%) rate of occurrence. This study revealed a need for hospital wastewater to be properly treated before discharged into water bodies and the environment to forestall the indiscriminate discharge of wastewater harbouring ESBL-producing bacteria.

Refine search results

Factors Affecting the Performance of Double Chamber Microbial Fuel Cell for Simultaneous Wastewater Treatment and Power Generation

Biosorption of toxic metals using freely suspended Microcystis aeruginosa biomass

A silica gel-bound macrocycle system for the selective separation of toxic cadmium from metal-affluent aqueous matrix

A comparison of fluorescein and deuterated water as tracers for determination of constructed wetland retention time

Photocatalytic decolorization of methyl orange solution with potassium peroxydisulfate

Extended Spectrum Beta Lactamase (ESBL) producing enteric bacteria from hospital wastewater, Ibadan, Nigeria