Adsorption and recovery of nonylphenol ethoxylate on a crosslinked beta-cyclodextrin-carboxymethylcellulose polymer

Water Sci Technol. 2010;61(9):2293-301. doi: 10.2166/wst.2010.152.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adsorption
  • Carboxymethylcellulose Sodium / chemistry*
  • Ethylene Glycols / chemistry*
  • Molecular Structure
  • Polymers / chemistry*
  • Waste Disposal, Fluid
  • Water / chemistry
  • Water Pollutants, Chemical / chemistry
  • Water Purification / methods
  • beta-Cyclodextrins / chemistry*

Substances

  • Ethylene Glycols
  • Polymers
  • Water Pollutants, Chemical
  • beta-Cyclodextrins
  • Water
  • terics
  • betadex
  • Carboxymethylcellulose Sodium