Adsorption of Cationic Contaminants by Cyclodextrin Nanosponges Cross-Linked with 1,2,3,4-Butanetetracarboxylic Acid and Poly(vinyl alcohol)

Abstract

Cationic organic pollutants (dyes and pesticides) are mainly hydrosoluble and easily contaminate water and create a serious problem for biotic and abiotic species. The elimination of these dangerous contaminants from water was accomplished by adsorption using cyclodextrin nanosponges. These nanosponges were elaborated by the cross-linking between 1,2,3,4-butanetetracarboxylic acid and β-cyclodextrin in the presence of poly (vinyl alcohol). Their physicochemical characteristics were characterized by gravimetry, acid-base titration, TGA, 13C NMR, ATR-FTIR, Raman, X-ray diffraction, and Stereomicroscopy. The BP5 nanosponges displayed 68.4% yield, 3.31 mmol/g COOH groups, 0.16 mmol/g β-CD content, 54.2% swelling, 97.0% PQ removal, 96.7% SO removal, and 98.3% MG removal for 25 mg/L of initial concentration. The pseudo-second-order model was suitable for kinetics using 180 min of contact time. Langmuir isotherm was suitable for isotherm with the maximum adsorption of 120.5, 92.6, and 64.9 mg/g for paraquat (PQ), safranin (SO), and malachite green (MG) adsorption, respectively. Finally, the reusability performance after five regeneration times reached 94.1%, 91.6%, and 94.6% for PQ, SO, and MG adsorption, respectively.

Cyclodextrin-Based Nanosponges: Overview and Opportunities

“…Recently, poly (vinyl alcohol)-βCD has been synthesised and its adsorption performance evaluated towards paraquat. The obtained material shows a very fast adsorption of pesticide, with a RE of around 96% in just 3 min, following a Langmuir mechanism ( Martwong et al, 2021 , 2022 ).…”

Adsorption of Cationic Pollutants from Water by Cotton Rope Coated with Cyclodextrin Polymers

“…A concentration of paraquat of 0.1 mg/L has been the maximum permissible concentration for drinking water [11]. Different adsorbents have been elaborated for PQ adsorption such as kaolin [12], activated carbon [13], bentonite [14], cellulose nanofiber [15], biobased material [16][17][18], cyclodextrin polymers coated on textile [19,20], and cyclodextrin nanosponges [21][22][23][24]. Methylene blue (MB) is a hydrosoluble cationic dye with the chemical structure of thiazine that is used as a dye for the textile coloration, a medication for the treatment of methemoglobinemia, a stain for chromoendoscopy or different staining procedures, an antidote to potassium cyanide poisoning, a redox indicator in analytical chemistry, and a treatment for fungal infections in aquaculture [25].…”

Cotton Cord Coated with Cyclodextrin Polymers for Paraquat Removal from Water

“…Furthermore, this method has possibly featured excellent removal efficiency for pollutants from water and obtained considerable attention in recent years because of the low investment costs, the minimal energy requirements, the ease of operation, the recyclability and selectivity of adsorbents, and the flexibility for technology transfer [ 10 ]. Various effective environment-friendly adsorbents were prepared for PQ removal such as activated carbon [ 11 ], bentonite [ 12 ], bio-based material [ 13 , 14 , 15 ], cellulose nanofiber [ 16 ], cyclodextrin polymers coated on textile [ 17 , 18 ], cyclodextrin nanosponges [ 19 , 20 , 21 , 22 ], kaolin [ 23 ], and microorganisms [ 24 ].…”

“…Moreover, the appearance of charge or different functional groups on cyclodextrin and its derivatives could enrich the adsorption capacity of organic molecules. A tetrafunctional cross-linking agent (1,2,3,4-butanetetracarboxylic acid (BTCA)) was used as a bridging agent to establish the cross-linked network with cyclodextrin to form insoluble nanosponges for the adsorption of bisphenol A, radionuclides (Uranium (VI) and Europium (III)) [ 48 ], and paraquat [ 17 , 19 , 22 ]. BTCA was also used to react with cellulose [ 49 , 50 ], starch [ 51 ], poly (vinyl alcohol) [ 52 , 53 ], and wool [ 54 ].…”