A study by non-isothermal thermal methods of spruce wood bark materials 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 pro- cesses 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 resi- due remaining after thermo-oxidative degradation, as well as the activation energies of the significant thermo-destruction stages, estimated from non-isothermal thermo- gravimetric data, together with the thermal quantities calculated from DTA data sup- port the conclusion presented in a previous study on dye retention from aqueous so- lution. 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.