Conducting polypyrrole films as a potential tool for electrochemical treatment of azo dyes in textile wastewaters

Kinetic model and thermodynamic study of Acid Red 1 entrapment at electropolymerised polypyrrole films

“…Polypyrrole-Acid Red 1 films were prepared by following a procedure previously reported by us [24]. Briefly, each polypyrrole-Acid Red 1 film was galvanostatically polymerised on a 3 cm  1.5 cm stainless steel working electrode (manufactured by Macquarie Engineering and Technical Services, Macquarie University) in the presence of 0.2 mol L À1 pyrrole and 60-2000 mg L À1 Acid Red 1 for a duration from 20 to 480 min.…”

“…Recently, we have reported the application of the conducting polymer, polypyrrole, as a potential green technology to electrochemical treatment of azo dyes using Acid Red 1 (5-(acetylami no)-4-hydroxy-3-(phenylazo)-2,7-naphthalenedisulfonic acid) as a model dye [24]. The structural formula of Acid Red 1 is depicted in Fig.…”

“…Similarly, by applying a reduction potential of À0.80 V, the polypyrrole film gains electrons and becomes neutral, resulting in the liberation of Acid Red 1 from the film [24]. In the presence of an Acid Red 1 solution, the dye is then easily re-entrapped in the film at +0.88 V for a desired period and again liberated at À0.80 V. In our pilot study [24], we have successfully synthesised polypyrrole-Acid Red 1 films and characterised them by microscopy and spectroscopy, the results of which supported Acid Red 1 entrapment by polypyrrole during oxidation of pyrrole. In the same study, we have used a two-level full factorial design to determine that the solution pH, initial concentration of Acid Red 1 and polymerisation time were all significant factors affecting the Acid Red 1 entrapment process at polypyrrole films.…”

“…[24], followed by examining the possible isotherms and the associated thermodynamics at the polypyrrole film-Acid Red 1 solution interface. Different dye adsorption kinetics, isotherm and thermodynamics at different materials have already been reported in literature, for example, a reactive dye at chemically prepared polypyrrole-saw dust [33], Tartrazine at chemically oxidised polypyrrole and polyaniline [34,35], Amido Black 10B at a chemically oxidised polyaniline/iron oxide composite [36], Acid Blue 193 at benzyltrimethylammonium bentonite [37] and natural sepiolite [38].…”

Application of PVDF ultrafiltration membranes to treat and reuse textile wastewater

“…There are more than 100,000 different synthetic dyes and their annual production is about 7·10 5 tonnes [3]. Particularly, the textile industry consumes 10 7 kg of dye per year [4] and 15% of dyes consumed are discharged into the textile wastewater [5] causing serious problems upon aquatic flora and fauna [6].…”