Adsorption of methylene blue from an aqueous solution using a cucurbituril polymer

Abstract

This article presents a study on the batch adsorption of methylene blue (MB) in an aqueous solution onto a cucurbituril polymer (CP) in order to explore its potential use as an adsorbent for dye removal from wastewater. Equilibrium studies showed that MB had a high affinity in a basic medium, but decreased as solution pH decreased. The adsorption of MB decreased with an increase in ionic strength for all four types of cations (Na+, K+, Mg2+, and Ca2+). The pseudo first‐order, pseudo second‐order kinetic model, and the intraparticle diffusion model were used to fit the kinetics process of MB adsorption on the CP. The result implies that the pseudo second‐order model provided a high degree of correlation with the experimental data, and intraparticle diffusion is not the only rate‐limiting step. The experimental isotherm data were analyzed using the Langmuir, Freundlich, and Redlich–Peterson isotherm model at initial pH 5.6 and 11. Five error analysis methods were used to evaluate the data. The error values indicated that the Redlich–Peterson and Langmuir models could provide the better quality of fit at initial pH 5.6, and Redlich–Peterson and Freundlich models described better the MB adsorption data at initial pH 11.0. © 2014 American Institute of Chemical Engineers Environ Prog, 34: 512–519, 2015

Fabrication, characterization and adsorption properties of cucurbit[7]uril-functionalized polycaprolactone electrospun nanofibrous membranes

“…Compared with the reported works on CB[ n ]-based absorbents [34–36], the maximum adsorption capacity of MB by PCL/CB[7] nanofibrous membranes is relatively low. The unexpected low adsorption capacity for MB should be mainly ascribed to the weak binding between CB[7] and MB in ethanol, as in non-aqueous solvents the hydrophobic effect is tremendously weakened.…”

“…According to the comparison of correlation coefficients R 2 , it is apparent that the experimental equilibrium adsorption data of MB by PCL/CB[7] nanofibrous membranes are better fitted with the Langmuir isotherm model. Therefore, it is easily concluded that the adsorption of MB took place at specific homogeneous sites within the nanofibrous membrane and formed a monolayer coverage of MB at the surface of the nanofibrous membrane [34].…”

Assessment of cationic dye biosorption onto anaerobic digested sludge: Spectroscopic characterization

“…New environmentally friendly adsorbents are also being developed and have also been tested for the removal of MB. This is the case for Cucurbit[n]uril (CB[n]) attached to a carrier, to allow its use for the adsorption of cationic dyes . Following this line, the direct use of sewage sludge as an absorbent whenever possible may be of great interest since the reduction in costs is significant and the relatively high adsorption capacity of this sort of material has been widely proven (above 100 mg g −1 for pyrolyzed and dehydrated sewage sludge) .…”

Preparation of an allyloxy-cucurbit[6]uril-modified polymer monolithic column for microextraction of estrogens in cosmetics

“…22 CBs have the structure of a hydrophobic cavity with identical carbonylfringed portals, which makes them have great potential in the field of adsorption. 23 For instance, there have been reports about the adsorption of sulfamonomethoxine antibiotics, 22 gases, 24 oils, 25 humic acid, 26 and methylene blue 27 with CBs and their derivatives. In our previous work, a CB [6] pseudorotaxane was employed to modify a poly(glycidyl methacrylate-co-ethylene dimethacrylate) monolithic column and applied to the efficient enrichment of nitroaromatics.…”