Search results for " Metals"

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…

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…

Statistical characterisation of heavy metal contents inParacentrotus lividusfrom Mediterranean Sea

2014

This work focuses on the estimation of Hg, As, Cr, Ni, Cu, V, Cd and Pb by inductively coupled plasma mass spectrometry in 135 adult specimens of Paracentrotus lividus collected in different coastal areas of Sicily (Gela, Punta Secca, Ragusa (RG), Siracusa, Priolo, Catania, Messina, Milazzo, Brolo and Filicudi), in order to monitor the Mediterranean marine ecosystem by use of sea urchin as bioindicator. Moreover, the paper deals with the statistical classification of the tested samples according to the sampling area based on metal concentrations. The descriptive statistics findings were obtained and, a starting multivariate matrix was built. Data-sets were subjected to Kruskal-Wallis test t…

Синтез и оптические свойства монокристаллических слоев окислов щелочноземельных металлов

1980

Coping with uncertainty in the assessment of atmospheric pollution with lichen transplants

2019

In the assessment of atmospheric deposition using lichen transplants, coping with uncertainty is mandatory in cases of environmental forensics, when understanding whether an area is polluted or not, or tracing a given pollution source is of paramount importance. In this article, we have suggested a method based on the calculation of exposed-to-control ratios of element concentrations and on the quantification of the overall uncertainty associated with such calculation, which proved to be very robust and can be applied in most cases using a minimum of three replicates. The method allowed the selection of significantly accumulated elements i.e. those polluting the site under study, as well as…

Use of stevia and chia seeds for the formulation of traditional and vegan artisanal ice cream

2021

Abstract Gelato is the name of the Italian-style artisanal ice cream, a nutritious product widely consumed in different parts of the world. Due to the high content in simple sugars, ice cream should be consumed moderately by diabetic patient. This research aimed to create artisanal ice cream, using Stevia rebaudiana, a plant well known for its sweet taste and its hypoglycemic effect. Traditional and vegan ice cream were formulated using stevia and chia seeds, in order to obtain products with appreciable rheological, textural and sensorial properties. Physical and sensorial properties of the ice cream formulation containing milk protein (traditional) or vegan substitute, were evaluated. Resu…

Benzothiazolethione complexes of coinage metals: from mononuclear complexes to clusters and polymers

2019

Abstract The reactions of 2(3H)-benzothiazolethione (Hbtt) with [AuCl(tetrahydrothiophene)] and CuBr2 were studied, and found to yield a tetranuclear cluster compound [Au(btt)]4 [1] and a polymeric structure [CuBr(btt-btt)]n.nTHF (2). Crystallographic and spectroscopic methods were used for the characterization. In 1, the monoanionic ligand acted as a bidentate bridging N,S-donor giving a molecular cluster structure of an asymmetric coordination isomer. In the formation of 2, the ligand was dimerized by forming a S–S bond after deprotonation, and coordination via nitrogen donors to metal atoms took place leading to a polymeric structure. To clarify the diversity of reactions of Hbtt with co…

Indoor air quality in schools of a highly polluted south Mediterranean area

2019

This study aimed at surveying lower secondary schools in southern Italy, in a highly polluted area. A community close to an industrial area and three villages in rural areas was investigated. Indoor temperature, relative humidity (RH), gaseous pollutants (CO 2 and NO 2 ), selected biological pollutants in indoor dust, and the indoor/outdoor mass concentration and elemental composition of PM 2.5 were ascertained. Temperature and RH were within, or close to, the comfort range, while CO 2 frequently exceeded the threshold of 1000 ppm, indicating inadequate air exchange rate. In all the classrooms, median NO 2 levels were above the WHO threshold value. Dermatophagoides p. allergen concentration…

An increased sensitivity of hydrocarbons-degrading bacteria to heavy metals in the presence of diesel oil

2015

Phase diagram of calcium at high pressure and high temperature

2018

Resistively heated diamond-anvil cells have been used together with synchrotron x-ray diffraction to investigate the phase diagram of calcium up to 50 GPa and 800 K. The phase boundaries between the Ca-I (fcc), Ca-II (bcc), and Ca-III (simple cubic, sc) phases have been determined at these pressure-temperature conditions, and the ambient temperature equation of state has been generated. The equation of state parameters at ambient temperature have been determined from the experimental compression curve of the observed phases by using third-order Birch-Murnaghan and Vinet equations. A thermal equation of state was also determined for Ca-I and Ca-II by combining the room-temperature Birch-Murn…