Aspects regarding colour fastness and adsorption studies of a new azo-stilbene dye for acrylic resins

The aim of this study was the colour fastness investigation of the new synthetized direct symmetrical azo-stilbene dye, using two of the film field domain reference tests, namely the wet-scrub and the UV tests. The dye was incorporated in a water-based resin, and then was applied on a PCV foil. The film colour parameters were determined before and after 200 wet-scrub cycles. Further, the dye was mixed with an acrylo-polyurethanic resin and then was applied on an aluminium plate, which was exposed to UV radiation for 414 h. The film colour parameters were recorded periodically. The maxima of the reflectance spectra depend on the UV time exposure. The quality of the film was analysed by the degree of gloss. A second focus was the elimination of the dye’s traces from wastewaters (these may be resulted from the industries which apply surface coating methods), using the active carbon powder. The main operational adsorption process parameters influence were investigated. Equilibrium, kinetic and thermodynamic studies were performed. The adsorption process was confirmed by the CIEL*a*b* colour space analysis. All colour studies were investigated using UV–Vis spectroscopy.

The Removal of Deinking Wastewater Using Neutralization, Activated Carbon, and Hydrogen Peroxide Oxidation

Treatment of deinking wastewater with neutralization, activated carbon, and hydrogen peroxide oxidation is investigated. Discusses the various factors of the neutralization experiment and catalytic experiment on the influence of the experimental results. The results show that for the 20mL deinking wastewater, first neutralize it to pH=4 with dilute sulfuric acid, then the mass fraction of 0.8mLH2O2 (mass fraction of 30%) and 0.8g active carbon powder in oxidative 19min under conditions of pH=3 with an optimum addition of 0.8mg H2O2 (30%) as well as 0.8g active carbon powder, the CODcr can be reduced from 31000mg/L to 2300 mg/L, and the color unit can be reduced from 15000 to 0 after treatment ,its CODcr and color unit decrease significantly and the removal rates reach 90% and 100% respectively.

Orthogonal Experiments for Optimizing Adsorption of Methyl Orange from Aqueous Solution

The adsorption of methyl orange dye from aqueous solution was investigated with active carbon powder as sorbents. Effects of selected factors were studied through the use of L16 (44) orthogonal experiment for the optimal parameter. The results demonstrated that the orders of their influences were contact time > initial dye concentration > the dosage of active carbon powder > pH. It was then concluded that contact time must be given priority in removing methyl orange dye from wastewater. Under the optimum conditions (the dosage 10g, time70min, initial dye concentration 35mg/L, pH7), The active carbon powder possessed good adsorption capacity to methyl orange which the removal efficiency could reached 95.96%.