Preparation and characterization of aspartic acid doped polypyrrole for the efficient removal of Cr(VI) from aqueous solution. (June 2016)

• Record Type: Journal Article
• Authors: Amalraj, Augustine; Selvi, M. Kalai; Rajeswari, A.; Pius, Anitha
• Is Part Of: Journal of water process engineering. Volume 11(2016)
• Page Start: 162
• Page End: 173
• Publication Date: 2016-06
• Subjects: Aspartic acid -- Polypyrrole -- Hexavalent chromium -- Adsorption -- Isotherm; Water-supply engineering -- Periodicals; Saline water conversion -- Periodicals; Seawater -- Distillation -- Periodicals; Sanitary engineering -- Periodicals; Sewage -- Purification -- Periodicals; 627
• DOI: 10.1016/j.jwpe.2016.05.005
• Languages: English
• ISSNs: 2214-7144

Abstract

Graphical abstract: Highlights: Asp-PPy polymer composite was prepared and characterized for Cr(VI) removal. Adsorption capacity is highly dependent on pH. The maximum adsorption capacity is found to be 176.7 mg/g. The equilibrium adsorption data fit well to the Langmuir isotherm model. Asp-PPy can be reused four times without loss of its Cr(VI) removal efficiency. Abstract: A new aspartic acid doped polypyrrole (Asp-PPy) was prepared via in situ polymerization of pyrrole with aspartic acid for the removal of Cr(VI) from aqueous solutions. The prepared Asp-PPy was characterized using FT-IR, SEM with EDS, XRD, XPS and BET methods. The adsorption experiments were carried out in batch mode to optimize various parameters viz., contact time, pH, adsorbent dose, co-ions and temperature that influence the adsorption rate. Langmuir, Freundlich and Dubinin-Radushkevich adsorption isotherm models were applied to describe isotherm constants. Equilibrium data agreed well with the Langmuir isotherm model with maximum adsorption capacity of 176.7 mg/g. Thermodynamic studies revealed that the nature of adsorption is spontaneous and endothermic. The kinetic process demonstrates that the adsorption process follows pseudo-second-order and intra-particle diffusion models. The mechanism of Cr(VI) adsorption by Asp-PPy was governed by the ionic interaction between NH3 + of Asp and HCrO4 − ions. Asp-PPy can be reused successfully for the removal of Cr(VI) four times without loss of its removal efficiency. Asp-PPy can be a promising material to remove toxic Cr(VI) from the aqueous environment due to having high Cr(VI) capacity, good ion exchange property, non-toxic, environmental stability and low cost.