Adsorption isotherms and kinetic studies for the removal of toxic reactive dyestuffs from contaminated water using a viologen-based covalent polymer

Abstract

A polyviologen-based adsorbent was prepared via polymerization of a viologen-dialdehyde with a hydroxyl-substituted aryl-dihydrazide in acidified water. The viologen-based covalent polymer aerogel was then generated by freeze-drying. The adsorption of...

Simultaneous removal of Pb2+ and direct red 31 dye from contaminated water using N-(2-hydroxyethyl)-2-oxo-2H-chromene-3-carboxamide loaded chitosan nanoparticles

“…Several studies have reported maximum adsorption for anionic dyes at acidic pH. 15,[47][48][49][50] Under neutral and alkaline conditions, the functional groups of C1@CsNPs become either neutral or deprotonated. Thus, electrostatic attractions disappear, consequently, the R% of DR31 decreases.…”

“…Also, several reports found that the PFO gives the best t to the experimental data. 15,[57][58][59][60][61] For Pb 2+ adsorption, Table 2 shows that Elovich model has the highest R 2 and lowest error values indicating that the adsorption kinetics can be accurately described by Elovich model. Thus, according to Elovich assumptions, the adsorption of Pb 2+ onto C1@CsNPs follows a chemisorption process involving surface chelation, electron-transfer, and/or sharing/ exchange of electrons between C1@CsNPs and Pb 2+ .…”

“…6,9,13 In this context, several chemical, physical, biological and combined treatment techniques have been applied to remove dyes and trace metals from water. 1,2,4,14,15 Adsorption is one of these techniques that is characterized by high efficiency, cost effectiveness, simplicity, exibility, ease operation, inertness towards toxic contaminants and eco-friendliness. 2,5,6,10,12,16,17 Therefore, adsorption has gained immense attention as a promising technology for decontaminating water from toxic dyes and trace metals.…”

One-Step Room-Temperature Synthesis of Bimetallic Nanoscale Zero-Valent FeCo by Hydrazine Reduction: Effect of Metal Salts and Application in Contaminated Water Treatment

“…Several treatment methods such as flocculation, ultrafiltration, and the biological method have been used in textile wastewater treatment and have been shown to be inefficient. − On the contrary, the adsorption process, which is widely used, has been shown to be highly effective and more economical. , Numerous materials have been used as adsorbents. Among them, magnetic zero-valent-based bimetallic nanoparticles (NPs) have attracted growing interest owing to their promising features.…”

Simultaneous decolorization of anionic and cationic dyes by 3D metal-free easily separable visible light active photocatalyst

“…These wastewaters contain a variety of organic and inorganic contaminants (Liu et al 2021 ). Synthetic organic dyes are one of the largest groups of organic contaminants because of their extensive use in several industries (Kasumov et al 2021 ; Nour et al 2021 ). The features of synthetic dyes such as bio-recalcitrance, toxicity, carcinogenicity, mutagenicity, and light absorbance make them harmful to humans and aquatic environment (Kasumov et al 2021 ; Nour et al 2021 ; Zhang et al 2021 ).…”