Search Results

You are looking at 1 - 3 of 3 items for

  • Author or Editor: A. Meghea x
  • Refine by Access: All Content x
Clear All Modify Search

Abstract  

The adsorption of phenol and ten substituted phenols on activated carbon was examined. For a comparative study, the substituted phenols were selected after nature, position, and number of functional groups; they, are: o-,m-,p-cresol, o-,m-,p-chlorphenol, m-,p-nitrophenol, resorcine, and methyl-resorcine. p-chloraniline was also studied. The single solute data were statistically fitted on 13 isotherm models: the Freundlich, Langmuir, Freundlich-Langmuir, BET, Dubinin-Raduskevitch, the three parameters empirical equation proposed by Radke and Prausnitz, Redlich-Petersen, Tóth, Myers, as well as generalised, Volmer, virial and sigmoidal isotherms. A computer program was developed to determine the most precise parameter models. The prediction results on the adsorption isotherms are compared by absolute relative percent deviations.

Restricted access

Abstract  

The present paper deals with the competitive adsorption on activated carbon of three aqueous bi-solute systems (phenol/p-nitrophenol, phenol/p-chlorphenol, p-nitrophenol/p-chlorphenol) and of the tri-solute system phenol/p-nitrophenol/p-chlorphenol. In this context two experimental methods to evaluate the equilibrium characteristics for the adsorption of phenols on powdered activated carbon were used. The competitive adsorption data were statistically fitted on four models: the Langmuir competitive model, the Freundlich-Langmuir competitive model, and the Fritz-Schlunder model, the last one in two particular cases for the monosolute representation. The prediction for all models, excepting the Fritz-Schlunder model, were performed using only single-solute data, while the parameters for the Fritz-Schlunder model were obtained using both single and multi-solute data.

Restricted access

Abstract  

Composite SiO2—iron oxide materials were prepared by three experimental procedures. In the first case, the iron oxides were precipitated during a sol-gel process. In the second case, a SiO2 matrix was initially obtained, and the iron oxides were formed by thermal treatment after impregnation of a soluble Fe2+ salt in the previously processed matrix. In the third method, ferrite powders, prepared by wet chemical method, were embedded into a SiO2 based sol-gel matrix. Materials with convenient porosity and nano-sized iron oxide content could be prepared using the mentioned methods. The prepared composite has been tested for arsenic(V) removal.

Restricted access