International Journal of Environmental Sciences

Volume 2 Issue 3 2012           Pages:1609- 1624

The adsorptive removal of cationic dye from aqueous solution using Poly (methacrylic acid) Hydrogels:Part-I. equlibrium studies

Author Information:

Bajpai S.K and Mahendra Manika- Polymer  Research  Laboratory, Department of Chemistry, Govt. Model Science College Jabalpur, Madhya Pradesh, India

Chand Navin - Scientist G & Head Polymer Composites, Advanced Materials and Processes Research Institute, (AMPRI) (Formerly RRL) (CSIR), Bhopal 462064, Madhya Pradesh, India

In this work poly(methacrylic acid) hydrogels were prepared by free radical aqueous polymerization of methacrylic acid(MAc) using N,N’-methylene bisacrylamide (MB) as crosslinker and potassium persulfate (KPS) as initiator. The hydrogels were characterized by FTIR and TG analysis. The gels exhibited pH-dependent swelling behavior, with equilibrium   percent mass swellings of about 110 and 403 at pH 1.0 and 7.4 respectively. The swelling exponent, n, was found to be 0.31 and 0.59 respectively, thus indicating a diffusion controlled and chain relaxation controlled swelling at these pH values respectively. The equilibrium adsorption of a cationic dye Methylene Blue (MB) was studied at 250C using the Langmuir and the Freundlich adsorption isotherm models. The maximum sorption capacity Q0 was found to be 169.43 mg/g . The equilibrium dye uptake was found to increase with the pH of the adsorbate medium and attained an optimum value of 77.8 mg/g for the initial dye concentration of 200 mg/L at 250C at pH 5.2. The adsorption showed negative temperature dependency thus suggesting exothermic nature of the adsorption process. Finally, the various thermodynamic parameters were also evaluated.

Keywords : Adsorption, FT-IR, Thermodynamics, hydrogels, Isotherm

DOI: 10.6088/ijes.00202030046

© 2012 Copyright Bajpai S.K et al, licensee IPA.This is an open access article distributed under the Creative Commons Attribution License (2.0) which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The electronic version of the article can be downloaded below.

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