title: Development of a polyaniline-lignocellulose composite for optimal adsorption of Congo red.
abstract: A polyaniline lignocellulose composite (PLC) was synthesized and used in the removal of Congo red (CR) from aqueous solution. The adsorption process showed good fits to both the pseudo-second-order and pseudo-first-order models and the Redlich Peterson isotherm. Boundary layer diffusion was the rate-limiting step. The adsorption was spontaneous and endothermic. The combined effect of pH and initial dye concentration was antagonistic; the combined effect of initial dye concentration and temperature was synergistic, while the combined effect of pH and temperature was reciprocal. The maximum CR adsorption capacity of PLC was evaluated as 1672.5 mg g(-1). The optimal removal was calculated as 99.85% at pH 4.29, initial dye concentration of 28.5 mg L(-1) and adsorbent dosage of 0.69 g L(-1). The predicted removal capacity showed a good correlation to the experimental results. PLC has demonstrated a superior adsorption capacity to many other adsorbents reported and could be used as an efficient adsorbent for CR removal from industrial wastewater.
authors.affiliation: Department of Applied Chemistry, University of Johannesburg, Johannesburg, South Africa. Electronic address: sushanta.debnath@yahoo.com.
authors.forename: Sushanta
authors.initials: S
authors.lastname: Debnath
authors.affiliation: Department of Applied Chemistry, University of Johannesburg, Johannesburg, South Africa.
authors.forename: Niladri
authors.initials: N
authors.lastname: Ballav
authors.affiliation: Department of Applied Chemistry, University of Johannesburg, Johannesburg, South Africa; National Centre for Nano-structured Materials, Council for Scientific and Industrial Research (CSIR), Pretoria, South Africa. Electronic address: AMaity@csir.co.za.
authors.forename: Arjun
authors.initials: A
authors.lastname: Maity
authors.affiliation: Department of Applied Chemistry, University of Johannesburg, Johannesburg, South Africa. Electronic address: kriveshinip@uj.ac.za.
authors.forename: Kriveshini
authors.initials: K
authors.lastname: Pillay
mesh_terms: D000327:Adsorption; D000704:Analysis of Variance; D000814:Aniline Compounds / Q000737:chemistry*; D003224:Congo Red / Q000302:isolation & purification*; D004058:Diffusion; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008031:Lignin / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D008962:Models, Theoretical; D016062:Porosity; D012044:Regression Analysis; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D014961:X-Ray Diffraction
chemical_list: D000814:Aniline Compounds; C416807:polyaniline; C036909:lignocellulose; D003224:Congo Red; D008031:Lignin
keywords: Congo red; Kinetics; Polyaniline-coated lignocelluloses; Response surface methodology; Thermodynamics