Wyniki wyszukiwania - Biblioteka Nauki

1

Analiza azotanów i bromianów powstających podczas dezynsekcji wody ozonem

100%

Gierak A. , Leboda R.

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tom nr 4

13-16

EN

When the surface water to be treated contains bromides and ammonium salts, ozonation will stimulate the formation of bromates, nitrites and nitrates, which have been identified as potential cancerogenic species. The admissible concentration of nitrates defined in Polish Standards is 10 gN/m (which corresponds to ca. 44 gNO3/m3 ). In Germany, the admissible concentration of nitrites must not exceed 0.1 gN/m3 . In Poland, the admissible concentration ofbromates has not been established yet. The maximal admissible concentrations of bromates in drinking water recommended by US EPA and WHO range between 10 and 50mgBr03 /m3. Moreover, it is postulated that, in future, these levels should be decreased to 5 mg/m3 , as soon as appropriate methods have been developed to enable determination of such low bromate levels. The objective of the present study was to discuss the problems that have to be tackled when determining bromate and nitrate concentrations in municipal water by high-performance ion-exchange chromatograpliy (IC-HPLC) or other teclmiques. Our investigations fiave sliown that direct determinations of nitrates and bromates are feasible at concentrations of 2 gNO3/m3 and over 0.2 gBrO3/m3, respectively.

2

Mikrokolumnowa chromatografia cieczowa (caLC) – porównanie parametrów retencyjnych z danymi TLC

80%

Skorupa A. , Gierak A. , Łazarska I.

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2015

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tom Vol. 69, nr 9

600--605

PL

W artykule przedstawiono nową technikę chromatograficzną, kapilarną chromatografię cieczową (caLC), i możliwość jej zastosowania do analizy mieszaniny barwników spożywczych. Porównano chromatogramy uzyskane na płytkach do chromatografii cienkowarstwowej (TLC) oraz w kolumienkach kapilarnych (caLC). Zastosowano odwrócony układ faz, gdzie adsorbentem był modyfikowany żel krzemionkowy RP-8, a eluentem mieszanina: metanol-woda-kwas octowy (4:5:1, v/v). Porównano dane retencyjne uzyskane na płytkach TLC i w kapilarach caLC na różnych drogach rozwijania oraz w kapilarach o różnych średnicach i różnymi sposobami rozwijania chromatogramów (metodą wstępującą i zstępującą oraz horyzontalną).

EN

This article presents a new chromatographic technique, capillary action liquid chromatography (caLC) and a possibility of its application in the analysis of mixture of food dyes. This work compares chromatograms obtained on a plate of the thin layer chromatography (TLC) and in capillary columns (caLC). The reversed phases chromatography were applied, where modified silicate gel RP-8 was a sorbent, and eluent was a mixture: methanol-water-acetic acid (4:5:1, v/v). The paper compares the retention data obtained with capillary caLC and with TLC plates in various distance of development, additionally for analysis in capillaries with various inner diameters, and different modes of development (ascending, descending, horizontal).

3

Low-cost adsorbents derived from agricultural by-products/wastes for enhancing contaminant uptakes from wastewater: A Review

80%

Sulyman M. , Namiesnik J. , Gierak A.

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tom 26

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nr 2

EN

A major threat to the comfort of human life has been imposed by increased industrialization and urbanization. The generation and disposal of huge amounts of toxic materials and pollutants have heavily contaminated our environment. Some Organics such as synthetic dyes (SD) and heavy metals (HM) are becoming increasingly prevalent as the most dangerous pollutants in soil and surface water environments. They are causing great concern worldwide due to their toxicity to many life forms. Environmentally friendly utilization of agricultural by-products/waste materials either as raw materials or in production of so-called activated carbons (AC) is an important issue. Because it is apparent from our literature review that the main factors characterizing these materials are their affordability, local availability, and efficiencies in removing many unwanted toxics and pollutants, they therefore could be utilized instead of more conventional but expensive adsorbent materials, particularly in developing countries where many industries lack appropriate individual sewage treatment systems; even where they exist, they lack satisfactory functioning and maintenance because of the lack of good budgets. A number of case studies are supplied in this review. These case studies have pointed to the efficient removal of SD/HM ions from aqueous solutions by the agricultural by-products/wastes in the form of a raw material, signifying spent tea leaves (STL) as a good example. Besides, the efficient removal of such ions by AC produced from these agricultural by-products/wastes has also been given in detail, suggesting a variety of AC agricultural by-products/wastes sources. Both kinds are widely used adsorbents in the treatment of wastewaters. Our review has shown that these adsorbents are characterized by many exceptional physical and chemical features that make them widely used adsorbents in the treatment of wastewaters. The adsorption efficiencies by these substances were also affected by the characteristics of AC, which depend on the physical and chemical properties of the precursor (i.e., agricultural by-products/wastes) as well as on the activation method applied, which is either chemical or physical. The structural properties of the resulting AC can be affected by a number of factors such as time of activation, temperature of activation, and the oxidizing agent used in addition to the starting precursor.

4

Determination of phenylbutazone and oxyphenbutazone in bovine plasma using high performance liquid chromatography with UV detection

80%

Jedziniak P. , Szprengier-Juszkiewicz T. , Gierak A.

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nr 2