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Volume 7 Biosensors Journal
ISSN: 2090-4967 Electrochemistry 2018
June 11-12, 2018
June 11-12, 2018 | Rome, Italy
4th International Conference on Electrochemistry
Activated carbon felt and graphite felt as efficient electrode materials for sulfide removal from waste
water streams
N Sergienko1, O Gutierrez1, I Rodriguez Roda1, 2 and J Radjenovic1, 3
1Catalan Institute for Water Research, Spain
2LEQUiA - University of Girona, Spain
3Catalan Institution for Research and Advanced Studies, Spain
S ulfide, a by-product of many industrial processes, causes a wide number of environmental problems. Electrochemical
treatment is one of the most emerging techniques used for its removal nowadays since it offers low cost treatment that
allows robust removal of sulfide in situ . In this study we evaluated the efficiency of low cost electrode materials such as activated
carbon felt (ACF) and graphite felt (GF) and proposed the mechanismof sulfide removal. In order to avoid electrode passivation
with sulfur, different electrode regeneration strategies were evaluated. Both materials enabled complete removal of sulfide, with
ACF requiring lower energy, i.e., 4.6x10-3 Wh/L compared to GF (11x10-3 Wh/L). Also, the mechanism of sulfide removal on
ACF and GF was different. Sulfide removal on ACF occurred mostly due to its rapid chemisorption, as a result of which pre-
adsorbed HS reacted with oxygen functional group on the ACF surface and formed elemental sulfur. The resulting sulfur was
incorporated into the ACF matrix and therefore it was not available for recovery. As for GF, chemisorption also occurred, but
it was slower and less efficient due to the smaller surface area of the material, lower concentration of oxygen functional groups
at its surface and higher GF hydrophobicity. In addition to chemisorption, other processes contributed to sulfide removal,
including electrochemical oxidation of sulfide to elemental sulfur and indirect oxidation to sulphate with oxygen produced
on the anode due to parasitic reaction. To recover the GF electrode, electrodeposited sulfur was successfully reduced in situ
to sulfide/polysulfides. In this study, we confirmed that adsorption governs the process of sulfide removal when ACF is used
as an anode, while electro-oxidation likely plays a minor role. GF could be successfully applied for anodic oxidation of sulfide
present in wastewater. Moreover, the possibility of in situ regeneration of GF electrodes prolongs the lifetime of an electrode
and makes its application more sustainable..
Biosens J 2018, Volume 7
DOI: 10.4172/2090-4967-C1-003