A study by non-isothermal thermal methods of spruce wood bark materialss after their application for dye removal

This paper deals with a study of some materials obtained from spruce bark (Picea abies, Romania), after retention of some dyes frequently used in dyeing processes in the textile industry and waste water treatment. These materials obtained by dye retention exhibit a particular thermal behavior which is different from that of the blank sample (spruce bark). The characteristic temperatures, weight losses, the residue remaining after thermo-oxidative degradation, as well as the activation energies of the significant thermo-destruction stages, estimated from non-isothermal thermogravimetric data, together with the thermal quantities calculated from DTAdata support the conclusion presented in a previous study on dye retention from aqueous solution. The obtained results made evident that, under optimal retention conditions, spruce bark shows the highest retention capacity for the Basic Blue dye, followed by Direct Brown 95 and Direct Brown 2

Original scientific paper Thermokinetic study on the inactivation reactions of 1-methylphthalazinium ylids

Abstract: The present paper consists in a thermokinetic study on the dimerization reactions of 1-methylphthalazinium ylids with –NO2 (ylid 1) and, respectively, –O–CH3 (ylid 2) substituents in the p position of the benzoyl radical bound to the ylidic carbanion. From experimental data, the reaction order and rate constants have been calculated. The reaction order n = 2 confirmed the ylids ’ dimerization reactions, while the values of the rate constants, k2 = 3.093 ���-2 L/mol s and, respectively, 2.16 � 10-1 L/mol s for the dimerization of ylids 1 and 2 made evident the higher reactivity of ylid 2 versus ylid 1. The same conclusion is also supported by the results of the thermodynamic study based on the chemical affinity of the two reactions, when Ao dim,1 < Ao dim,2

Thermokinetic study on the inactivation reactions of 1-methylphthalazinium ylids

The present paper consists in a thermokinetic study on the dimerization reactions of 1-methylphthalazinium ylids with NO2 (ylid 1) and, respectively, OCH3 (ylid 2) substituents in the p position of the benzoyl radical bound to the ylidic carbanion. From experimental data, the reaction order and rate constants have been calculated. The reaction order n = 2 confirmed the ylids dimerization reactions, while the values of the rate constants, k2 = 3.093×10-2 L/mol s and, respectively, 2.16×10-1 L/mol s for the dimerization of ylids 1 and 2 made evident the higher reactivity of ylid 2 versus ylid 1. The same conclusion is also supported by the results of the thermodynamic study based on the chemical affinity of the two reactions, when Aodim,1 < Aodim,2

JSCS–3372 Original scientific paper

A study by non-isothermal thermal methods of spruce wood bark materialss after their application for dye remova