Adsorption and recovery of nonylphenol ethoxylate on a crosslinked beta-cyclodextrin-carboxymethylcellulose polymer.
A study of adsorption/recovery of nonylphenol 9 mole ethoxylate (NP9EO) on a crosslinked beta-cyclodextrin-carboxymethylcellulose (beta-CD-CMC) polymer was carried out by ultraviolet-visible (UV-vis) and Fourier transform infrared (FTIR) spectroscopies. The adsorption was performed in mixtures containing 500 mg of the beta-CD-CMC polymer and aqueous NP9EO solutions at concentrations 12-82 mg/L, whereas the recovery of NP9EO was effectuated by shaking the beta-CD-CMC polymer loaded with methanol. The assays were made at 25 degrees C and atmospheric pressure under agitation. The results have shown that the adsorption is a rapid process and the beta-CD-CMC polymer exhibits a high NP9EO adsorption capacity of 83-92 w% (1.1-6.8 mg NP9EO/g beta-CD-CMC polymer) dependent of the initial NP9EO concentration in liquid phase. This adsorption may involve the formation of an inclusion complex beta-CD-NP9EO and a physical adsorption in the polymer network. The adsorption equilibrium measurements, which were analyzed using the Langmuir isotherm, have indicated a monolayer coverage and the homogeneous distribution of active sites at the surface of the beta-CD-CMC polymer. Moreover, the negative value obtained for the free energy change (-13.2 kJ/mol) has indicated that the adsorption process is spontaneous. In parallel, the beta-CD-CMC polymer exhibited a high NP9EO recovery efficiency of 97 w% that may occur through a decrease of binding strength between beta-CD-CMC polymer and NP9EO. Together, these results suggest that the beta-CD-CMC polymer could constitute a good adsorbent for removing nonylphenol ethoxylates from wastewater due to its high adsorption capacity and non-toxic character of beta-CD and CMC to environment.
Bonenfant
Danielle
D
Département de génie de la construction, STEPPE-Ecole de Technologie Supérieure, 1100, Notre-Dame Ouest, Montréal Québec, Canada H3C 1K3. Danielle.Bonenfant@ens.etsmtl.ca
Niquette
Patrick
P
Mimeault
Murielle
M
Hausler
Robert
R
D000327:Adsorption; D002266:Carboxymethylcellulose Sodium / Q000737:chemistry*; D005026:Ethylene Glycols / Q000737:chemistry*; D015394:Molecular Structure; D011108:Polymers / Q000737:chemistry*; D014865:Waste Disposal, Fluid; D014867:Water / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000737:chemistry; D018508:Water Purification / Q000379:methods; D047392:beta-Cyclodextrins / Q000737:chemistry*
D005026:Ethylene Glycols; D011108:Polymers; D014874:Water Pollutants, Chemical; D047392:beta-Cyclodextrins; D014867:Water; C021754:terics; C031215:betadex; D002266:Carboxymethylcellulose Sodium