Removal of methyl orange dye and copper (II) ions from aqueous solution using polyaniline-coated kapok (Ceiba pentandra) fibers.

Water Sci Technol. 2018 Oct;78(5):1137-1147. doi: 10.2166/wst.2018.385. Herrera MU1, Futalan CM2, Gapusan R3, Balela MDL3. Author information 1 Institute of Mathematical Sciences and Physics, College of Arts and Sciences, University of the Philippines Los Baños, Laguna, 4031, Philippines E-mail: mlbalela1@up.edu.ph. 2 Environment Business Line, Aecom Philippines Consultants Corporation, Bonifacio Global City, Fort Bonifacio, Taguig 1634, Philippines. 3 Sustainable Electronic Materials Group, Department of Mining, Metallurgical and Materials Engineering, College of Engineering University of the Philippines Diliman, Quezon City 1101, Philippines. Abstract Hollow tubular structured kapok fibers (Ceiba pentandra) were coated with polyaniline (PANI) molecules using an in situ oxidative polymerization technique. The tubular morphology of the kapok fibers was retained after PANI coating. The Fourier transform infrared (FT-IR) spectrum of the PANI-coated kapok fibers illustrated the vibration modes associated with the presence of PANI molecules. The PANI-treated kapok fibers achieved complete wettability with water molecules (zero water contact angle) from initially being highly hydrophobic (contact angle = 120°). In the present work, the removal of contaminants such as methyl orange dye and Cu(II) from aqueous solution using polyaniline-coated kapok fibers was investigated. Isotherm studies show that the removal of methyl orange dye (R2 ≥ 0.959) and Cu(II) (R2 ≥ 0.972) using PANI-coated kapok fibers follow the Langmuir isotherm model with maximum sorption capacities determined to be 75.76 and 81.04 mg/g, respectively. Based from thermodynamic studies, the sorption of methyl orange dye and Cu(II) are endothermic, feasible and spontaneous. Furthermore, kinetic studies show that the both processes follow a pseudo-second-order model, implying that the rate-determining step is chemisorption. PMID: 30339538 PMCID: wst_2018_385 DOI: 10.2166/wst.2018.385 Share on FacebookShare on TwitterShare on Google+