scholarly journals Evaluation of Benzene Derivatives Migration from Solid Residuals by Alternative Leaching Process Using HS‑SPME GC‑MS

Author(s):  
Jocinei Dognini ◽  
Luiz Madureira
Tehnika ◽  
2021 ◽  
Vol 76 (4) ◽  
pp. 426-436
Author(s):  
Miroslav Sokić ◽  
Branislav Marković ◽  
Dušan Milojkov ◽  
Aleksandra Patarić ◽  
Mladen Bugarčić ◽  
...  

The results of polymetallic sulphide Cu-Zn-Pb concentrate leaching with sulphuric acid in the presence of sodium nitrate as an oxidizing agent, at atmospheric pressure, are presented and discussed. Chemical composition and phase ratio of the starting concentrate and solid residuals after the leaching process are shown. Chemical reactions of leaching and their thermodynamic probabilities are predicted based on the calculated Gibbs energies and analysis of E-pH diagrams. The influence of temperature and time on the leaching degree of the concentrate's components is experimentally determined. It is shown that it is possible to obtain copper, zinc and iron in a solute form, while lead in the anglesite (PbSO4) form remains in the solid residual after the leaching process. The iron is being oxidized to Fe(III)-sulphate, which takes part in a sulphide leached minerals and turns into Fe(II)-sulphate.


1991 ◽  
Vol 88 ◽  
pp. 509-514 ◽  
Author(s):  
MA Cuevas Diarte ◽  
T Calvet ◽  
M Labrador ◽  
E Estop ◽  
HAJ Oonk ◽  
...  

Author(s):  
Autumn Flynn ◽  
Kelly McDaniel ◽  
Meredith Hughes ◽  
David Vogt ◽  
Nathan Jui

A photocatalytic system for the dearomative hydroarylation of benzene derivatives has been developed. Using a combination of an organic photoredox catalyst and an amine reductant, this process operates through a reductive radical-polar crossover mechanism where aryl halide reduction triggers a regioselective cyclization event, giving rise to a range of complex spirocyclic cyclohexadienes. This light-driven protocol functions at room temperature in a green solvent system (aq. MeCN), without the need for precious metal-based catalysts or reagents, or the generation of stoichiometric metal byproducts.


1985 ◽  
Vol 20 (2) ◽  
pp. 36-43 ◽  
Author(s):  
Klaus L.E. Kaiser ◽  
Juan M. Ribo ◽  
Brian M. Zaruk

Abstract This paper gives the results of part of a systematic investigation into contaminant toxicity to Photobacterium phosphoreum in the Microtox™ test. Reported are the toxicity values for 39 para-chloro substituted benzene derivatives of the general formula l-Cl-C6h4-4-X=CH2CH(NH2)COOH, F, SO2NH2, OCH2COOH, CH2COOH, CONHNH2, NHCOCH3, CONH2, CH=CHCOOH, SeOOH, CH2NH2, CH2CH2NH2, NO2, H, CF3, CHO, CH2OH, OH, CH3, CCl3, COCH3, COOH, NH2, SO2C6H5, Cl, CH2COCH3, COCl, CN, OCH3, NCO, NHCH3, I, COC6H5, CH2Cl, SH, CH2SH, NCS, CH2CN and SO2C6H4Cl. Except for the last compound, whose solubility is below the required concentration, the toxicities increase in the presented order with a total range of more than three orders of magnitude. The data are discussed in terms of quantitative structure-toxicity correlations with compound-specific structural parameters. In combination with a previously developed submodel on chlorinated benzenes, phenols, nitrobenzenes and anilines, the observed relationships allow the prediction of the toxicity of some 780 possible chloro derivatives of the general formula C6H5-nClnX, where n=<5 and X is a functional group as listed above.


Author(s):  
Yusup Hendronursito ◽  
Muhammad Amin ◽  
Slamet Sumardi ◽  
Roniyus Marjunus ◽  
Frista Clarasati ◽  
...  

This study was aimed to increase granite's silica content using the leaching process with HCl concentration variation. The granite used in this study came from Lematang, South Lampung. This study aims to determine the effect of variations in HCl concentration, particle size, and rotational speed on the crystalline phase and chemical elements formed in the silica product produced from granite. The HCl concentration variations were 6.0 M, 7.2 M, 8.4 M, and 9.6 M, the variation in particle size used was 270 and 400 mesh. Variations in rotational speed during leaching were 500 and 750 rpm. Granite powder was calcined at 1000 ºC for 2 hours. Characterization was performed using X-Ray Fluorescence (XRF), X-Ray Diffraction (XRD), and Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP- OES). The results showed that the silica content increased with increasing HCl concentration, the finer the particle size, and the higher the rotational speed. XRF analysis showed that the silica with the highest purity was leached with 9.6 HCl with a particle size of 400 mesh and a rotational speed of of 750 rpm, which was 73.49%. Based on the results above, by leaching using HCl, the Si content can increase from before. The XRD diffractogram showed that the granite powder formed the Quartz phase.


1969 ◽  
Vol 24 (11) ◽  
pp. 1365-1370 ◽  
Author(s):  
H.-H. Perkampus ◽  
U. Krüger ◽  
W. Krüger

The proton chemical shifts of aromatic compounds are strongly concentration dependent. Moreever, for molecules with a dipole moment a temperature dependence of the proton chemical shifts is observed. For hemellitone, p-methylanisole, o-chlortoluene, p-chlortoluene, pyrrole and N-methyl-pyrrole the enthalpies of a dipole-dipole association between -0,7 and -1,8 Kcal could be estimated by NMR measurements combined with the temperature dependence in the whole range of the molefraction (0 → 1).


2021 ◽  
Vol 6 (3) ◽  
pp. 425-429
Author(s):  
Haleemathul Zahadiya ◽  
Ruwan P. Wijesundera ◽  
Champika V. Hettiarachchi ◽  
Ishanie R. Perera

1978 ◽  
Vol 9 (31) ◽  
Author(s):  
V. A. GRINBERG ◽  
V. R. POLISHCHUK ◽  
L. S. GERMAN ◽  
L. S. KANEVSKII ◽  
YU. B. VASIL'EV
Keyword(s):  

1999 ◽  
Vol 23 (1) ◽  
pp. 60-61
Author(s):  
O. I. Kalchenko ◽  
A. V. Solovyov ◽  
J. Lipkowski ◽  
V. I. Kalchenko

Stability constants of the host–guest complexes of 5,17-bis( N-tolyliminomethyl)-25,27-dipropoxycalix[4]arene with benzene derivatives were determined by reversed-phase HPLC in acetonitrile–water solution.


Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 810
Author(s):  
Zhanyong Guo ◽  
Ping Guo ◽  
Guang Su ◽  
Fachuang Li

In this paper, nickel-containing residue, a typical solid waste produced in the battery production process, was used to study the cavitation characteristics of ultrasonic waves in a liquid–solid reaction. The ultrasonically-enhanced leaching technology for multicomponent and complex nickel-containing residue was studied through systematic ultrasonic-conventional comparative experiments. An ultrasonic leaching kinetics model was established which provided reliable technological guidance and basic theory for the comprehensive utilization of nickel-containing residue. In the study, it was found that ultrasonically-enhanced leaching for 40 min obtained the same result as conventional leaching for 80 min, and the Ni extraction degree reached more than 95%. According to the kinetic fitting of the leaching process, it was found that the sulfuric acid leaching process belonged to the diffusion-controlled model of solid product layers under conventional and ultrasonic conditions, and the activation energy of the reaction was Ea1 = 17.74 kJ/mol and Ea2 = 5.04 kJ/mol, respectively.


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