Immobilization of metal–humic acid complexes in anaerobic granular sludge for their application as solid-phase redox mediators in the biotransformation of iopromide in UASB reactors
2016; Elsevier BV; Volume: 207; Linguagem: Inglês
10.1016/j.biortech.2016.01.125
ISSN1873-2976
AutoresAracely S. Cruz-Zavala, Aurora M. Pat‐Espadas, J. René Rangel-Méndez, Luis F. Cházaro-Ruíz, Juan A. Ascacio‐Valdés, Cristóbal N. Aguilar, Francisco J. Cervantes,
Tópico(s)Pharmaceutical and Antibiotic Environmental Impacts
ResumoMetal-humic acid complexes were synthesized and immobilized by a granulation process in anaerobic sludge for their application as solid-phase redox mediators (RM) in the biotransformation of iopromide. Characterization of Ca- and Fe-humic acid complexes revealed electron accepting capacities of 0.472 and 0.556milli-equivalentsg(-1), respectively. Once immobilized, metal-humic acid complexes significantly increased the biotransformation of iopromide in upflow anaerobic sludge blanket (UASB) reactors. Control UASB reactor (without humic material) achieved 31.6% of iopromide removal, while 80% was removed in UASB reactors supplied with each metal-humic acid complex. Further analyses indicated multiple transformation reactions taking place in iopromide including deiodination, N-dealkylation, decarboxylation and deacetylation. This is the first successful application of immobilized RM, which does not require a supporting material to maintain the solid-phase RM in long term operation of bioreactors. The proposed redox catalyst could be suitable for enhancing the redox conversion of different recalcitrant pollutants present in industrial effluents.
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