Modeling of Experimental Adsorption Isotherm Data

Adsorption is considered to be one of the most effective technologies widely used in global environmental protection areas. Modeling of experimental adsorption isotherm data is an essential way for predicting the mechanisms of adsorption, which will lead to an improvement in the area of adsorption science. In this paper, we employed three isotherm models, namely: Langmuir, Freundlich, and Dubinin-Radushkevich to correlate four sets of experimental adsorption isotherm data, which were obtained by batch tests in lab. The linearized and non-linearized isotherm models were compared and discussed. In order to determine the best fit isotherm model, the correlation coefficient (r2) and standard errors (S.E.) for each parameter were used to evaluate the data. The modeling results showed that non-linear Langmuir model could fit the data better than others, with relatively higher r2 values and smaller S.E. The linear Langmuir model had the highest value of r2, however, the maximum adsorption capacities estimated from linear Langmuir model were deviated from the experimental data.

[1]  D. Kinniburgh,et al.  General purpose adsorption isotherms. , 1986, Environmental science & technology.

[2]  G. Zeng,et al.  Removal of phosphate from aqueous solution by magnetic Fe-Zr binary oxide , 2011 .

[3]  Liang Yan,et al.  Adsorption of phosphate from aqueous solution by hydroxy-aluminum, hydroxy-iron and hydroxy-iron-aluminum pillared bentonites. , 2010, Journal of hazardous materials.

[4]  G. P. Thim,et al.  Adsorption of phosphate from aqueous solution by hydrous zirconium oxide , 2012, Environmental technology.

[5]  Jun Yang,et al.  One-Pot Synthesis of Mesoporous MCM-41 with Different Functionalization Levels and their Adsorption Abilities to Phosphate , 2012 .

[6]  T. Waite,et al.  Effects of pH, floc age and organic compounds on the removal of phosphate by pre-polymerized hydrous ferric oxides , 2012 .

[7]  G Thompson,et al.  The treatment of pulp and paper mill effluent: a review. , 2001, Bioresource technology.

[8]  M. Dubinin,et al.  The Equation of the Characteristic Curve of Activated Charcoal , 1947 .

[9]  Xian-Zheng Yuan,et al.  Phosphorus fixation in lake sediments using LaCl3-modified clays. , 2009 .

[10]  Kai Xu,et al.  One-pot synthesis of Fe(III)-coordinated diamino-functionalized mesoporous silica: Effect of functionalization degrees on structures and phosphate adsorption , 2013 .

[11]  Irving Langmuir,et al.  The constitution and fundamental properties of solids and liquids. Part II.—Liquids , 1917 .

[12]  Y. Ho.  Isotherms for the Sorption of Lead onto Peat: Comparison of Linear and Non-Linear Methods , 2006 .

[13]  I. Langmuir.  THE CONSTITUTION AND FUNDAMENTAL PROPERTIES OF SOLIDS AND LIQUIDS , 1917 .

[14]  K. Y. Foo,et al.  Insights into the modeling of adsorption isotherm systems , 2010 .

[15]  Xinze Wang,et al.  Phosphorus removal from wastewater using nano-particulates of hydrated ferric oxide doped activated carbon fiber prepared by Sol–Gel method , 2012 .

[16]  Kai Xu,et al.  Fabrication of Fe-coordinated diamino-functionalized SBA-15 with hierarchical porosity for phosphate removal , 2013 .