Chromatographic Separation, Total Determination and Chemical Speciation of Mercury in Environmental Water Samples Using 4-(2-Thiazolylazo) Resorcinol-Based Polyurethane Foam Sorbent-Packed Column

2019 ◽  
Author(s):  
Amal H. Al-Bagawi ◽  
Waqas Ahmad ◽  
Hassan Alwael ◽  
Zeinab M. Saigl ◽  
Gharam I. Mohammed ◽  
...  
Keyword(s):  
Polyurethane Foam ◽  
Water Samples ◽  
Chromatographic Separation ◽  
Chemical Speciation ◽  
Packed Column ◽  
Environmental Water ◽  
Environmental Water Samples

scholarly journals Preparation and Utilization of the Precursor Activated Carbon from Carbon Enriched Fuel Oil Fly Ash: Part II Removal and Speciation of Chromium(III and VI) from Wastewater

2017 ◽  
Vol 12 (3) ◽  
pp. 553-566 ◽  
Author(s):  
A. Abu-Rizaiza ◽  
M.W. Kadi ◽  
M.S. El-Shahawi
Keyword(s):  
Activated Carbon ◽  
Water Samples ◽  
Packed Column ◽  
Environmental Water ◽  
Steam Gasification ◽  
Procaine Hydrochloride ◽  
Environmental Water Samples ◽  
Separation Mechanism ◽  
Binary Complex ◽  
Chromium Vi

Activated carbon (AC) prepared from residual fly (FA) was activated by combined CO2-steam gasification and physically modified with procaine hydrochloride (PQ+Cl-). Modified AC was used as low cost and effective solid phase extractor (SPE) for removal, total determination and chemical speciation of chromium(III&VI) in wastewater. Pseudo-second order rate equation is proposed for assigning the kinetics of chromium(VI) sorption in aqueous HCl (1.0 mol L-1) by PQ+Cl-- modified AC . The data were correlated with surface structure of the SPE. A dual separation mechanism of chromium(VI) as a binary complex ion associate [PQ+.CrO3Cl-] in/on the modified AC via "weak base anion exchanger" and an added component of “surface adsorption” is proposed. At 2 mL min-1 flow rate Sorption of spiked chromium(VI) at known concentrations (0.5-20 mg mL-1) from water onto modified AC packed columns at 2 mL min-1 was achieved. The sorbed chromium(VI) species were successfully recovered (106.0±2- 110 ±3%, n=3) from AC packed column with NaOH (10 mL, 1.0 mol L-1). Chromium(III) after oxidation to chromium(VI) was also enriched and eluted from the AC packed column and analyzed. Modified PQ+Cl- AC packed column was also used for total determination and speciation of chromium(III & VI) species at trace levels in environmental water samples. Good apparent recovery percentage (94.6±6.3-102.0± 8.5 %) of chromium species was achieved confirming the analytical utility of the modified AC-packed column for removal, total determination and speciation of chromium(III & VI) species in environmental water samples.

Improving Mycobacterium spp. detection in water: a new methodological proposal

2004 ◽  
Vol 4 (2) ◽  
pp. 103-106
Author(s):  
R. Santos ◽  
S. Gonçalves ◽  
F. Macieira ◽  
F. Oliveira ◽  
R. Rodrigues ◽  
...  
Keyword(s):  
Water Samples ◽  
Recovery Rate ◽  
Opportunistic Infections ◽  
Environmental Water ◽  
Environmental Water Samples ◽  
Sample Treatment ◽  
Detection Time ◽  
Fast Detection ◽  
Enrichment Step ◽  
Mycobacterium Spp

In recent years, non-tuberculous mycobacteria (NTM), once considered merely environmental saprophytes, have emerged as a major cause of opportunistic infections. There is no evidence of human-to-human transmission but they have been found in several environmental water samples. It is, therefore, of the utmost importance to develop methods of rapidly and accurately detecting non-tuberculous mycobacteria in water samples. To obtain a maximum recovery rate and a reduction of Mycobacterium spp. detection time in water samples, different decontamination, enrichment procedures and antibiotics supplements were tested before the inoculation into the Bactec® system. The proposed method of sample treatment (decrease in the decontamination time, followed for a peptone pre-enrichment step and an aztreonam and cefepime supplement) before the inoculation into the Bactec® system proved to be a good option for reliable and fast detection of Mycobacterium spp. in water samples.

The Occurrence of Male-Specific and Somatic Bacteriophages in Polluted South African Waters

1991 ◽  
Vol 24 (2) ◽  
pp. 251-254 ◽  
Author(s):  
R. Kfir ◽  
P. Coubrough ◽  
W. O. K. Grabow
Keyword(s):  
South African ◽  
Water Samples ◽  
Biological Treatment ◽  
Environmental Water ◽  
Environmental Water Samples ◽  
Resistance Pattern ◽  
Male Specific

The occurrence of somatic (F') and male-specific (F') coliphages and Salmonella phages in a variety of environmental water samples was studied using different bacterial hosts. The number of plaque-forming units (pfu) of the different bacteriophages were compared and their resistance pattern to a biological treatment (humus tank) and chlorination was evaluated. The presence of the bacteriophages in shellfish was also studied. The morphology of isolate bacteriophages was examined as well as the visibility of the different plaques formed. Coliphages were found to produce larger and clearer plaques than all other bacteriophages studied. In most of the environmental water samples coliphages outnumbered all other bacteriophages, with the exception of dam water in which higher levels of F' Salmonella phages were detected. The majority of the F' Salmonella phages were shown to be RNA bacteriophages.

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