A potential application of sludge-based catalysts for the anaerobic bio-decolorization of tartrazine dye

Abstract

Two highly efficient (K₂CO₃/sludge carbon and ZnCl₂/sludge carbon) solids were prepared by chemical addition following carbonization at 800 °C and were tested for anaerobic reduction of tartrazine dye in a continuous upflow packed-bed biological reactor, and their performance was compared to that of commercial activated carbon (CAC). The chemical and structural information of the solids was subjected to various characterizations in order to understand the mechanism for anaerobic decolorization, and efficiency for SBCZN800 and SBCPC800 materials was 87% and 74%, respectively, at a short space time (τ) of 2.0 min. A first-order kinetic model fitted the experimental points and kinetic constants of 0.40, 0.92 and 1.46 min⁻¹ were obtained for SBCZN800, SBCPC800 and CAC, respectively. The experimental results revealed that performance of solids in the anaerobic reduction of tartrazine dye can depend on several factors including chemical agents, carbonization, microbial population, chemical groups and surface chemistry. The Langmuir and Freundlich models are successfully described in the batch adsorption data. Based on these observations, a cost-effective sludge-based catalyst can be produced from harmful sewage sludge for the treatment of industrial effluents.

Keywords:

• sewage sludge
• carbonization
• bio-decolorization
• tartrazine
• wastewaters

Disclosure statement

No potential conflict of interest was reported by the authors.

Funding

Financial support for this research was provided by the Q3 Spanish Ministerio de Educación y Ciencia and FEDER, projects CTM2008-03338 and CTM2011-23069. The financial support (2010BRDI/06-35) for the doctoral fellowship from the Universitat Rovira i Virgili (Tarragona, Spain) is gratefully acknowledged. The author's research group is recognized by the Comissionat per a Universitats i Recerca del DIUE de la Generalitat de Catalunya (2009SGR865) and supported by the Universitat Rovira i Virgili (2010PFR-URV-B2-41).

ORCID

Josep Font http://orcid.org/0000-0002-4007-7905

Frank Stüber http://orcid.org/0000-0001-9424-1400

Christophe Bengoa http://orcid.org/0000-0001-9160-5010