title: Single stage batch adsorber design for efficient Eosin yellow removal by polyaniline coated ligno-cellulose.
abstract: Polyaniline-coated lignin-based adsorbent (PLC) was synthesized and used for uptake of reactive dye eosin yellow (EY) from aqueous solution. The adsorption capability of the adsorbent was found to be more effective than the unmodified adsorbent (LC). In particular, the adsorption capability of the PLC was effective over a wider pH range. This could be owing to its higher point of zero charge, which is more favorable for the uptake of the anionic dye. Adsorption isotherm models suggested a monolayer adsorption was predominant. The mean free energy of adsorption (E(DR)) was found to have values between 8 and 16 kJ mol(-1) which suggests that an electrostatic mechanism of adsorption predominated over other underlying mechanisms. The adsorption process was also found to be spontaneous, with increasing negative free energy values observed at higher temperatures. Chemisorption process was supported by the changes in enthalpy above 40 kJ mol(-1) and by the results of desorption studies. This new adsorbent was also reusable and regenerable over four successive adsorption-desorption cycles. The single stage adsorber design revealed that PLC can be applicable as an effective biosorbent for the treatment of industrial effluents containing EY dye.
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. Electronic address: nballav2@gmail.com.
authors.forename: Niladri
authors.initials: N
authors.lastname: Ballav
authors.affiliation: National Centre for Nano-structured Materials, Council for Scientific and Industrial Research (CSIR), Pretoria, South Africa; Department of Civil and Chemical Engineering, University of South Africa (UNISA), 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; D000814:Aniline Compounds / Q000737:chemistry* / Q000378:metabolism; D004801:Eosine Yellowish-(YS) / Q000737:chemistry* / Q000302:isolation & purification; D007700:Kinetics; D008031:Lignin / Q000737:chemistry* / Q000378:metabolism; D008956:Models, Chemical; D012996:Solutions / Q000737:chemistry; D013816:Thermodynamics
chemical_list: D000814:Aniline Compounds; D012996:Solutions; C416807:polyaniline; C036909:lignocellulose; D008031:Lignin; D004801:Eosine Yellowish-(YS)
keywords: Adsorption; Eosin yellow; Polyaniline coated ligno-cellulose