Alumina-silica-titania adsorbent for hazardous azo and phtalocyanine dyes removal from textile baths and wastewaters – the impact of ionic surfactants

Abstract

Two aspects of interfacial phenomena were discussed in the manuscript. The first one concerns the adsorptive removal of two azo dyes such as C.I. Acid Yellow 219 (AY219) and C.I. Direct Yellow 142 (DY142) as well as the phtalocyanine C.I. Reactive Blue 21 (RB21) on the alumina-silicatitania oxide (4% wt. Al2O3-8% wt. SiO2-88% wt. TiO2; AST88) in the ionic surfactants presence. The second one deals with the determination of interaction mechanism in the dyes-AST88, dyes-surfactant-AST88 systems using the data obtained from the surface charge density and zeta potential studies. The sodium dodecyl sulphate (SDS) with anionic character and hexadecyltrimethylammonium bromide (CTAB) with cationic ones were used. The adsorption capacities of 205.2 mg/g for AY219, 36.5 mg/g for RB21 and 18 mg/g for DY142. The potentiometric titration and Doppler laser electrophoresis methods enable determination of sign and magnitude of charge located in both the surface and the slipping plane layers around the solid particles. The structure of electrical double layer was determined in the AST88 systems without as well as with dyes and with mixed dye + surfactant adsorbates.

Activated biocarbons obtained from post-fermentation residue as potential adsorbents of organic pollutants from the liquid phase

“…Moreover, such effect observed for MG is considerably greater than that of MB. The adsorption of cationic molecules causes the creation of additional number of negatively charged surface groups on the activated biocarbon surface, and thus the absolute value of the solid negative The analogous behaviour was noted in the systems containing ionic dye and other solids, namely simple and mixed oxides (Wawrzkiewicz et al 2017(Wawrzkiewicz et al , 2019Wiśniewska et al 2008Wiśniewska et al , 2020. For these suspensions the adsorption of anionic dye resulted in the solid surface charge density increase, whereas the adsorption of cationic dye caused its decrease (due to the creation of additional surface groups oppositely charged in relation to the adsorbate molecules).…”

“…For these suspensions the adsorption of anionic dye resulted in the solid surface charge density increase, whereas the adsorption of cationic dye caused its decrease (due to the creation of additional surface groups oppositely charged in relation to the adsorbate molecules). Some changes in the surface properties of the solid in the dye presence can be also caused by the formation of hydrogen and chemical bonds between the nitrogen and sulfur atoms with free electron pairs and activated biocarbon surface groups, mainly of acidic character (Wiśniewska et al 2020).…”

Wpływ Surfaktantów Na Właściwości Adsorpcyjne Substancji Organicznych I Jonów Metali Ciężkich W Układach Koloidalnych

“…Podobne mechanizmy wiązania barwnika w obecności anionowego i kationowego surfaktantu zaobserwowano w układzie zawierającym tlenek potrójny AST88 i barwniki AY219, DY142 oraz RB21, chociaż w tym przypadku obecność kationowego surfaktantu skutkowała obniżeniem wielkości adsorpcji barwnika [39]. Prawdopodobnie związane było to z tym, że utworzone kompleksy barwnik-CTAB wykazywały słabsze powinowactwo do aktywnych miejsc powierzchniowych ciała stałego i jednocześnie silną tendencję do pozostawania w roztworze.…”

“…Możliwe typy oddziaływań cząsteczek badanych barwników z miejscami aktywnymi na powierzchni tlenku mieszanego[39] Figure4.…”

Removal of methylene blue from aqueous solutions via adsorption on activated biocarbon obtained from post-extraction residue

“…One of the main problems of wastewater treatment is the removal of dyes and heavy metals (Yagub et al, 2014). It can be realised via osmosis or coagulation processes, but the most effective and relatively cheap method is adsorption on porous sorbents, due to the high efficiency of the process and the possibility of recovering many of the removed contaminants, for example metal ions (Wiśniewska et al, 2020;Wawrzkiewicz et al, 2019;Rafati et al, 2016;Peruchi et al, 2015;Saleh and Gupta, 2012;Huang and Chen, 2009). Activated carbons are the most often used materials for this purpose.…”