Search results for "metals"
showing 10 items of 2013 documents
Influence of Heavy Metal Concentration on Chlorophyll Content in Pleurozium schreberi Mosses
2020
Abstract The aim of biomonitoring is assessment of environment condition. Biomonitoring studies with the use of mosses focus mainly on analytes accumulation and determining elements’ concentrations in the study area. It is often forgotten that a bioindicator should be alive during biomonitoring studies (which can be determined by, e.g., analysis of chlorophyll content). The objective of the carried out research was an assessment of the influence of selected heavy metals concentration: Ni, Cu, Zn, Cd and Pb accumulated by Pleurozium schreberi mosses during 3-month exposition within active biomonitoring, on their vitality, assessed by an analysis of a and b chlorophyll concentrations. The stu…
Organic matter quantity and quality, metals availability and foraminiferal assemblages as environmental proxy applied to the Bizerte Lagoon (Tunisia)
2016
International audience; This study analyzes the benthic trophic state of Bizerte Lagoon (Tunisia) based on the total organic matter and the bioavailability of biopolymeric carbon including proteins (PTN), carbohydrates (CHO), lipids (LIP), chlorophyll a, as well as bacteria counts. The overall simultaneously extracted metals (SEM), and acid volatile sulfides (AVS) as well as the SEM/AVS ratio indicative of the toxicity of the sediments also were analyzed aiming to study their impact in the dimension, composition and structure of both dead and living benthic foraminiferal assemblages.In the studied sites TOC content is relatively high and the PTN/CHO values indicate that they can be consider…
A battery of toxicity tests as indicators of decontamination in composting oily waste.
2000
Heterogeneous oily waste from an old dumping site was composted in three windrows constructed from different proportions of waste, sewage sludge, and bark. The objectives of this pilot study were to examine the usefulness of composting as a treatment method for this particular waste and to study decontamination in the composting process by using a battery of toxicity tests. Five samples from the windrow having intermediate oil concentrations were tested with toxicity tests based on microbes (Pseudomonas putida growth inhibition test, ToxiChromotest, MetPLATE, and three different modifications of a luminescent bacterial test), enzyme inhibition (reverse electron transport), plants (duckweed …
Optically Detected Magnetic Resonance of Chlorophyll Triplet States in Water-Soluble Chlorophyll Proteins from Lepidium virginicum: Evidence for Exci…
2018
Optically detected magnetic resonance of triplet states populated by photoexcitation in water-soluble chlorophyll proteins (WSCPs) from Lepidium virginicum has been performed using both absorption and fluorescence detection. Well resolved triplet-singlet (T-S) spectra have been obtained and interpreted in terms of electronic interactions among the four chlorophylls (Chls), forming two dimers in the WSCP tetramer. Localization of the triplet state on a single Chl leads to a redistribution of the oscillator strength in the remaining three Chls of the complex. By comparing the spectra with those obtained on a substoichiometric WSCP complex containing only 2 Chls per protein tetramer, we proved…
Cr(VI) sorption by intact and dehydrated Candida utilis cells in the presence of other metals
2002
This study examined the Cr(VI), Cu(II), Zn(II), Cd(II), Pb(II) sorption by intact and dehydrated Candida utilis cells. The anion [Cr2O7]2− and cation Me2+ sorption kinetics was investigated in both single- and dual-metal situations. Uptake of chromate anions occurred much more slowly singularly than with metal cations. A combination of Pb or Cu and chromate anions gave a synergistic effect for Cr(VI) sorption, but not Cd and Zn, which inhibited Cr(VI) sorption by dehydrated cells. The use of alcian blue to occupy maximum vacant adsorption sites on the cell surface unexpectedly did not influence further adsorption of Me2+. Metal uptake by C. utilis was 7 mg (135 μM) Cr, 23 mg (362 μM) Cu, 39…
Towards a revisitation of vesuvianite-group nomenclature: the crystal structure of Ti-rich vesuvianite from Alchuri, Shigar Valley
2016
Vesuvianite containing 5.85 wt% TiO2from an Alpine-cleft-type assemblage outcropped near Alchuri, Shigar Valley, Northern Areas, has been investigated by means of electron microprobe analyses, gas-chromatographic analysis of H2O, X-ray powder diffraction, single-crystal X-ray structure refinement,27Al NMR,57Fe Mössbauer spectroscopy, IR spectroscopy and optical measurements. Tetragonal unit-cell parameters are:a= 15.5326 (2),c= 11.8040 (2) Å, space groupP4/nnc. The structure was refined to finalR1= 0.031,wR2= 0.057 for 11247I> 2σ(I). A general crystal-chemical formula of studied sample can be written as follows (Z= 2):[8–9](Ca17.1Na0.9)[8]Ca1.0[5](Fe2+0.44Fe3+0.34Mg0.22)[6](Al3.59Mg0.41)…
Protection against chemical submission: naked-eye detection of γ-hydroxybutyric acid (GHB) in soft drinks and alcoholic beverages
2020
Two new oxazole derivatives, able to detect γ-hydroxybutyric acid (GHB) in soft drinks and alcoholic beverages, by color and fluorescence changes, are reported.
Effect of pruning-derived biochar on heavy metals removal and water dynamics
2014
Biomass-derived biochar is considered as a promising heavy metal adsorbent, due to abundance of polar functional groups, such as carboxylic, hydroxyl, and amino groups, which are available for heavy metal removal. The aims of this study were to evaluate the effectiveness of an orchard pruning-derived biochar in removing some heavy metals (through the evaluation of isotherms) and to study water dynamics at the solid-liquid interface as affected by heavy metal adsorption (through an innovative nuclear magnetic resonance (NMR) relaxometry approach). Both isotherms and NMR spectra revealed that Pb and Cr showed a good affinity for the biochar surface (Pb > Cr), while Cu was less affine. Accordi…
A new selective fluorogenic probe for trivalent cations.
2012
[EN] A new selective chromo-fluorogenic probe for Fe 3+, Cr 3+ and Al 3+ is reported. Detection limits are in the ¿M range and the fluorogenic sensing ability could be observed by the naked eye when illuminated with UV-light. No response is observed with divalent cations. © 2012 The Royal Society of Chemistry.
Toxicity of binary mixtures of Cu, Cr and As to the earthworm Eisenia andrei
2020
AbstractChromated copper arsenate (CCA) mixtures were used in the past for wood preservation, leading to large scale soil contamination. This study aimed at contributing to the risk assessment of CCA-contaminated soils by assessing the toxicity of binary mixtures of copper, chromium and arsenic to the earthworm Eisenia andrei in OECD artificial soil. Mixture effects were related to reference models of Concentration Addition (CA) and Independent Action (IA) using the MIXTOX model, with effects being related to total and available (H2O and 0.01 M CaCl2 extractable) concentrations in the soil. Since only in mixtures with arsenic dose-related mortality occurred (LC50 92.5 mg/kg dry soil), it wa…