Search results for "POLLUTANTs"
showing 10 items of 1125 documents
Spectroscopic and conformational properties of size-fractions separated from a lignite humic acid
2007
Abstract A lignite humic acid (HA) was fractionated by preparative high performance size-exclusion chromatography (HPSEC) in seven different size-fractions. The size-fractions were characterized by cross polarization (CP) magic angle spinning (MAS) 13 C NMR spectroscopy and a further analytical HPSEC elution under UV and fluorescence detection. The alkyl hydrophobic components mainly distributed in the largest molecular-size-fraction, whereas the amount of oxidized carbons increased with decreasing size of fractions. Cross polarization time ( T CH ) and proton spin-lattice relaxation time in the rotating frame ( T 1 ρ (H)) were measured from variable contact time (VCT) experiments. The bulk…
Effects of sewage sludge addition to Norway spruce seedlings on nitrogen availability and soil fauna in clear-cut areas
2012
Anaerobically digested and composted sewage sludge (CSS) has been suggested to be a slow-release fertilizer in forestry and an alternative to quick-release inorganic fertilizers. The effects of CSS with or without added carbohydrate on inorganic nitrogen availability and on soil animals were tested in two Norway spruce plantations. Half of the seedlings were individually fertilized with CSS, and the rest were left as controls. Solid sucrose was added to half of the fertilized and untreated seedlings. Soil samples were taken in the autumn in the first and the second year after the treatments. CSS increased soil NH4-N (2100%), the proportion of soil NO3-N, and the N concentration of spruce ne…
Combined use of liquid chromatography triple quadrupole mass spectrometry and liquid chromatography quadrupole time-of-flight mass spectrometry in sy…
2012
As a suitable way for routine screening of pesticides and control of other organic contaminants in water, the combination of liquid chromatography triple quadrupole tandem mass spectrometry (LC-QqQ-MS/MS) and liquid chromatography-hybrid quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) has been applied to the analysis of 63 surface and waste water samples after conventional solid-phase extraction (SPE). The extracts were screened for 43 pesticides or degradation products by LC-QqQ-MS/MS achieving limits of detection (LOD) ranged from 0.04 to 2 ng L(-1). Of the 43 selected pesticides, 33 were detected in water samples. The ESI-QTOF MS instrument was run using two simultaneous acquisi…
Identification and dose dependency of ibuprofen biliary metabolites in rainbow trout
2012
Abstract The biotransformation of the anti-inflammatory drug ibuprofen (IBF) was studied by exposing rainbow trout ( Oncorhynchus mykiss ) to IBF via intraperitoneal (i.p.) injection, and via water at four (0.17, 1.9, 13 and 145 μg L −1 ) exposure levels for 4 d. Following exposure, the bile was collected and analyzed by LC–MS/MS methods. The identification of the formed metabolites in i.p. injected fish bile was based on the exact mass determinations by a time-of-flight mass analyzer (Q–TOF–MS) and on the studies of fragments and fragmentation patterns of precursor ions by ion trap mass analyzer (IT-MS). In addition to unmetabolized IBF, several phase I and phase II metabolites were found …
Green determination of the presence of volatile organic compounds in vehicle repair shops through passive sampling.
2012
A simple, fast and green direct analytical methodology has been developed to evaluate the concentration level of volatile organic compounds (VOCs) in indoor areas of vehicle repair shops using membrane devices as passive samplers. VOCs retained in the samplers were directly determined without any sample pre-treatment and avoiding the use of solvents by head space (HS) coupled to gas chromatography-mass spectrometry (GC-MS) in only 20 min. Benzene, toluene, tetrachloroethene, m,p-xylene and o-xylene were found at concentration levels from 0.1 to 11.2 mg m(-3).
Chitosan Functionalized with Carboxyl Groups as a Recyclable Biomaterial for the Adsorption of Cu (II) and Zn (II) Ions in Aqueous Media
2022
The modification of chitosan represents a challenging task in obtaining biopolymeric materials with enhanced removal capacity for heavy metals. In the present work, the adsorption characteristics of chitosan modified with carboxyl groups (CTS-CAA) towards copper (II) and zinc (II) ions have been tested. The efficacy of the synthesis of CTS-CAA has been evaluated by studying various properties of the modified chitosan. Specifically, the functionalized chitosan has been characterized by using several techniques, including thermal analyses (differential scanning calorimetry and thermogravimetry), spectroscopies (FT-IR, XRD), elemental analysis, and scanning electron microscopy. The kinetics an…
Pineapple peel biochar and lateritic soil as adsorbents for recovery of ammonium nitrogen from human urine.
2021
Abstract Human urine is a rich source of nitrogen which can be captured to supplement the existing sources of nitrogen fertilizers thus contributing to enhanced crop production. However, urine is the major contributor of macronutrients in municipal wastewater flows resulting into eutrophication of the receiving water bodies. Herein, pineapple peel biochar (PPB), and lateritic soil (LS) adsorbents were prepared for the safe removal of ammonium nitrogen (NH4+-N) from human urine solutions. Physicochemical properties of PPB, and LS were characterized by scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy…
Ambient Air Pollution and Atherosclerosis: Insights Into Dose, Time, and Mechanisms.
2021
Ambient air pollution due to particulate matter ≤2.5 μ is the leading environmental risk factor contributing to global mortality, with a preponderant majority of these deaths attributable to atherosclerotic cardiovascular disease (ASCVD) causes such as stroke and myocardial infarction. Epidemiological studies in humans have provided refined estimates of exposure risk, with evidence suggesting that risk association with particulate matter ≤2.5 levels and ASCVD continues at levels well below air quality guidelines in North America and Europe. Mechanistic studies in animals and humans have provided a framework of understanding of the duration and pathways by which air pollution exposure may pr…
Cardiovascular effects of air pollution
2017
Air pollution is composed of particulate matter (PM) and gaseous pollutants, such as nitrogen dioxide and ozone. PM is classified according to size into coarse particles (PM 10), fine particles (PM 2.5) and ultrafine particles. We aim to provide an original review of the scientific evidence from epidemiological and experimental studies examining the cardiovascular effects of outdoor air pollution. Pooled epidemiological studies reported that a 10 μg/m 3 increase in long-term exposure to PM 2.5 was associated with an 11% increase in cardiovascular mortality. Increased cardiovascular mortality was also related to long-term and short-term exposure to nitrogen dioxide. Exposure to air pollution…
Cadmium regulation of apoptotic and stress response genes in tumoral and immortalized epithelial cells of the human breast
2008
Cadmium (Cd) is a widely-disseminated metal which can be imported and accumulated in living cells thereby drastically interfering with their biological mechanisms. Increasing interest has been recently focused on the elucidation of the cellular and molecular aspects of Cd-dependent regulation of gene expression and signal transduction pathways in different model system. Concerning breast cancer, very limited studies have been produced so far on the role played by Cd on estrogen receptor-negative human breast cancer cells, that are expected to be insensitive to the already-proven metallo-estrogenic effect exerted by Cd on the estrogen receptor-positive cell counterparts. Here, we have examin…