Search results for "Disposal"
showing 10 items of 1300 documents
A Method to Quantitatively Trap Volatilized Organoselenides for Stable Selenium Isotope Analysis
2011
If volatile organoselenides are to be analyzed for their stable Se isotope composition to elucidate sources and formation processes, organoselenides need to be trapped quantitatively to avoid artificial Se isotope fractionation. We developed an efficient trap of organoselenides to be used in microcosms designed to determine the Se isotope fractionation by microbial transformation of inorganic Se to volatile organoselenides. The recoveries of volatilized dimethyldiselenide (DMDSe) from aqueous standard solutions by activated charcoal and alkaline peroxide solution with subsequent freeze-drying and purification via a cation exchange resin were tested. Microcosm experiments with the Se-methyla…
Influence of ground tire rubber on the transient loading response of a peat biofilter
2010
Abstract The effect of using ground tire rubber (GTR) as an adsorptive material in the removal of a 2:1:1 weight mixture of n-butyl acetate, toluene and m-xylene by using a peat biofilter under different intermittent conditions was investigated. The performance of two identical size biofilters, one packed with fibrous peat alone and the other with a 3:1 (vol) fibrous peat and GTR mixture, was examined for a period of four months. Partition coefficients of both materials were measured. Values of 53, 118 and 402 L kg −1 were determined for n-butyl acetate, toluene and m-xylene in peat, respectively; and values of 40, 609 and 3035 L kg −1 were measured for the same compounds in GTR. Intermitte…
Comparison of different removal techniques for selected pharmaceuticals
2015
[EN] Recently, there is an emergence of endocrine-disrupting compounds, pharmaceuticals, and personal care products (EDC/PPCPs) as important pollutants to remove from drinking water and reclaimed wastewater. In this work, the efficiency of removing pharmaceuticals (PCs) from model aqueous solutions and raw wastewater with ultrafiltration (UF), nanofiltration (NF), activated carbon adsorption (AC), biological methods (SBR) and oxidation with ClO2 was investigated. Some treatments have also been used as combined processes: UF + NF, UF +AC, SBR + ClO2. Ibuprofen, Acetaminophen, Diclofenac, Sulfamethoxazole, Clonazepam, and Diazepam were selected as model compounds. In order to evaluate their r…
On-line Chloride Interference Removal for Arsenic Determination in Waste Water and Urine by ICP-MS Using a Modified Capillary
2002
The determination of arsenic in environmental samples like waste waters from industrial effluents and in biological samples like urine is very important due to the toxic nature of some of its species at moderate levels of exposure. The objective of this study was to evaluate the capability of modified anionic capillaries to remove chloride for ICP-MS determination of arsenic, which causes spectral interference due to formation of 40 Ar 35 Cl + . Also high chloride content gives non-spectral interferences. The results indicate that arsenic at a concentration higher than 1 µg L m 1 in a matrix with a chloride content up to 600 mg L m 1 can be accurately determined using a 3-aminopropyltrimeth…
Determination of Phenols from Automobile Exhaust by Means of High-Performance Liquid Chromatography (HPLC)
1981
Abstract The paper describes a procedure to determine ten representative phenols (phenol, m-, p-, o-cresol, 2,4-, 2,6-, 3,4-, 3,5-xylenol, 2,3,6-, 2,4,6-trimethylphenol) in engine exhaust. Sampling was performed by a conventional Grimmer device. A sample of the water condensate collected was extracted with ether. After concentration of the ether extract phenols were isolated from other interfering compounds by stepwise elution on a Lobar column packed with LiChroprep Si 60 under controlled conditions. Relative recovery of the majority of reference phenols ranged from 90-100%. Separation of phenols into individual components was performed on polar packings as well as on Reverse Phase packing…
Performance of a series of novel N-substituted acrylamides in capillary electrophoresis of DNA fragments
1996
DNA separations by capillary electrophoresis in viscous solutions of novel polymers, made with Ω-hydroxyl, N-substituted acrylamides (notably N-acryloyl amino propanol, AAP and N-acryloyl amino butanol, AAB) are evaluated. Whereas in standard poly(acrylamide), at 6% concentration, the theoretical plate number (N) does not exceed 500 000, in 6% poly(AAP) N reaches 922 000 and in 6% poly(AAB) N values as high as 1 200 000 are obtained. Also, copolymers of AAP and AAB give N values in excess of 1 million plates. The two novel monomers (AAP and AAB) remain extremely stable during alkaline hydrolysis and display very good hydrophilicity, while being devoid of the noxious habit of auto-polymeriza…
A clean analytical method for the spectrophotometric determination of formetanate incorporating an on-line microwave assisted hydrolysis step
1999
Abstract A fast and completely automated procedure is proposed for the spectrophotometric determination of formetanate in waters by means of its reaction with p-aminophenol (PAP). The method involves the on-line alkaline hydrolysis of formetanate to m-aminophenol (MAP) and its reaction, in the presence of KIO 4 as oxidant agent, with the quinoneimine form of PAP, to form a blue indophenol dye which absorbs at 576 nm. The on-line hydrolysis can be carried out in a 6 m reaction coil located inside the cavity of a domestic microwave oven operated at 650 W, or in a 4 m reaction coil located inside the cavity of a Microdigest 301 microwave system operated at 60 W and allows us, in both cases, a …
Solid-Phase Extraction of Organochlorine Pesticides from Water Samples
1990
Abstract A procedure for the accumulation of organochiorine pesticides by reversed-phase adsorption on octadecylsilica glass microcolumns was used for the isolation and concentration from spiked distilled and natural waters. The pesticides were eluted from the octadecylsilica with light petroleum, and analyzed by gas chromatography using an electron capture detector. The average recovery was over 90% in spiked water samples at 0.1 ng/ml. The performance of the octadecylsilica when applied to the analysis of water samples were compared with the Rodier and the APHA solvent extraction methods.
Cultivation of granular sludge with hypersaline oily wastewater
2015
The time required to stabilise mature aerobic granules is rather variable. In addition, cultivation time and the structural characteristics of granules seem to be related to the nature of wastewater influent. Granular sludge has been used for the treatment of several industrial wastewaters, but nothing has been reported about wastewater characterized by the simultaneous presence of hydrocarbons and high chloride concentration. In this work, the authors analysed the granulation process and performance as well as the physical characteristics of aerobic granules in two Granular Sequencing Batch Airlift Reactors (GSBARs), fed with acetate-based synthetic wastewater in reactor 1 (R1) and with a …
Classification of vegetable oils according to their botanical origin using n-alkane profiles established by GC-MS.
2013
n-Alkane profiles established by gas chromatography-mass spectrometry (GC-MS) were used to classify vegetable oils according to their botanical origin. The n-alkanes present in corn, grapeseed, hazelnut, olive, peanut and sunflower oils were isolated by means of alkaline hydrolysis followed by silica gel column chromatography of the unsaponifiable fractions. The n-alkane fraction was constituted mainly of n-alkanes in the range C8-C35, although only those most abundant (15 n-alkanes, from 21 to 35 carbon No.) were used as original variables to construct linear discriminant analysis (LDA) models. Ratios of the peak areas selected by pairs were used as predictors. All the oils were correctly …