Physicochemically modified peat by thermal and oxidation processes as an active material for purification of wastewaters from certain hazardous pollutants

The physicochemical modification of peat through thermal and oxidation processes was carried out, in order to obtain new, inexpensive and active material for purification of different types of waters. During the modification, surface chemical compounds of Shilov type were formed. Batch adsorption properties and suitability of physicochemically modified peat (PCMP) for odor removal were tested in aqueous solutions of H2S and colloidal sulphur. Additionally, PCMP was tested in the removal of As(V) which is hazardous ingredient in contaminated waters. Possible mechanisms of pollutants binding include interactions, which lead to formation of adducts and clathrates. All these processes are elucidated in detail. The results showed that the obtained material can be used for the removal of sulphide, colloidal sulphur and As(V) from different types of waters

Influence of the fluorescent brightener Periblanc BA on the degree of whiteness of the knitted cotton fabric

In this study the influence of the different fluorescent brightener Periblanc BA concentrations on the degree of knitted cotton fabric whiteness was investigated. Two consecutive experimental runs were performed. The first was the bleaching of the knitted cotton fabric with hydrogen peroxide using the methods of two and single bath exhaustion while the second was the optical bleaching with fluorescent brightener Periblanc BA using the exhaustion method. CIE Whiteness Index and Tint value were measured on the Color-Eye 3000 spectrophotometer at the standard illuminant D65 (Ice-Texicon, d/8, D65/10°) while K/S values were determined using the Kubelka Munk equation. The results show that cotton fabric bleached with fluorescent brightener Periblanc BA after bleaching with hydrogen peroxide using two bath exhaustion method has higher degree of whiteness (118.8) with a reddish tint in comparison to the one bleached with hydrogen peroxide using single bath method (106.1)

Determination of two reactive dyes concentration in dyed cotton fabric

The purpose of this paper was to determine the unknown concentration of dichlortriazinyl reactive dyes, namely Reactive Yellow 22 and Reactive Blue 163, in dyed cotton fabric. The samples of cotton fabric were dyed individually with each dye as well as with a mixture of two dyes. The unknown concentrations of dyes were determined by measuring the corresponding reflectance values of dyed fabric samples and then using the relation between the concentration and reflectance values of the samples. The method set by Kubelka and Munk was used. The accuracy and repeatability of the concentrations determination were calculated by the statistical processing of the data obtained by measurements. Relative errors of individual determination of Reactive Yellow 22 and Reactive Blue 163 were 3.66% and 5.94% respectively. Relative errors in determination of Reactive Yellow 22 and Reactive Blue 163 in a mixture were 3.47% and 3.19% respectively. The results showed that reflectance spectrophotometry can be successfully used as the method for concentration determination of Reactive Yellow 22 and Reactive Blue 163 in dyed cotton fabric and can therefore be applied as the shade control method in dyeing

Copper(II) and lead(II) complexation by humic acid and humic-like ligands

The stability of metal–humate complexes is an important factor determining and predicting speciation, mobility and bioavailability of heavy metals in the environment. A comparative investigation of the complexation of Cu(II) and Pb(II) with humic acid and humic-like ligands, such as benzoic and salicylic acid, was performed. The analysis was realized at pH 4.0, a temperature of 25 °C and at an ionic strength of 0.01 mol dm-3 (NaCl) using the Schubert ion-exchange method and its modified form. The stability constants were calculated from the experimental data by the Schubert method for complexes with benzoic and humic acid. A modified Schubert method was used for the determination of the stability constants of the complexes with salicylic acid. It was found that Cu(II) and Pb(II) form mononuclear complexes with benzoic and humic acid while with salicylic acid both metals form polynuclear complexes. The results indicate that Pb(II) has a higher binding ability than Cu(II) to all the investigated ligands. The Cu(II)–salicylate and Pb(II)–salicylate complexes showed noticeable higher stability constants compared with their complexes with humic acid, while the stabilities of the complexes with benzoic acid differed less. Salicylic and benzoic acids as humic-like ligands can be used for setting the range of stability constants of humic complexes with Cu(II) and Pb(II)