Azo dye decolorization in an up-flow bioelectrochemical reactor with domestic wastewater as a cost-effective yet highly efficient electron donor source

Abstract

a b s t r a c tA major challenge of employing bioelectrochemical system (BES) for reductively degrading recalcitrant contaminants in industrial wastewater is lacking sufficient electron donors. In this work, domestic wastewater (DW) was demonstrated to efficiently drive BES for implementing the decolorization of azo dye, acid orange 7 (AO7). Side benefit was the simultaneous treatment of DW. Decolorization efficiency in BES fed with DW (R DW ) was found to be comparable with that either fed with glucose (R Glu ) or acetate (R Ac ). Much lower reductant usage ratio was observed in R DW . As a result, when the ratio of electron donors to azo dye decreased to 4.4 mol COD mol À1 AO7, DE of R DW kept over 90% while DEs of R Ac and R Glu were significantly dropped due to the insufficient electrons donation. Besides serving as electron donor, DW was proved to also provide some conductivity and buffer capacity. Accordingly, DE of R DW was less deteriorated when fully removing the external buffer slats. This study comprehensively revealed the feasibility and superiority of DW as a cost-effective electron donor source in BES and brings this technology closer to the practice.

Decolorization of Reactıve Blue 19 Dye By Bacillus Megaterium Isolated From Soil

“…These types of dyes cannot be decolorized with chemical and physical methods led up to the idea that biological treatment methods are usable applications in eliminating environmental pollutions. Many conducted studies show that microorganisms are capable of eliminating a variety of synthetic dyes in aerobic and anaerobic conditions via biosorption, bioaccumulation, and biodegradation [6][7][8][9]. Conducted studies show that complex organic compounds are degraded by various enzymes such as laccase (EC 1.10.3.2) [10], lignin peroxidase (EC 1.11.1.14) [11], NADP-DCIP reductase(EC 1.6.99.3) [12] and tyrosinase (EC 1.14.18.1) [13].…”

Corrugated stainless-steel mesh as a simple engineerable electrode module in bio-electrochemical system: Hydrodynamics and the effects on decolorization performance

“…Bio-electrochemical systems (BESs) have been explored extensively for its innovative features and environmental benefits for the degradation of a number of recalcitrant contaminants [1,2], such as azo dyes [3][4][5], nitro-aromatics [6][7][8], and halogenated aromatics [9]. Although the BESs commonly shows a superior performance compared to the traditional biological processes, this technology is still far away from the full-scale application, which especially suffers from the high capital cost as well as the scaling-up of the electrode [2,10,11].…”

Increasing the bio-electrochemical system performance in azo dye wastewater treatment: Reduced electrode spacing for improved hydrodynamics

“…Recently, BESs have been explored extensively for its innovative features and environmental benefits for recalcitrant contaminants degradation in wastewater (Logan et al, 2006a,b;Rozendal et al, 2008), especially for azo dyes (Cui et al, 2016a;Mu, 2009;Sun et al, 2011), nitro-aromatics (Liang et al, 2014;Wang et al, 2011), and halogenated aromatics (Liang et al, 2013) reduction. However, most bio-electrochemical technologies developed until now have been restricted to lab scale as lacking of appropriate strategies to scaling-up.…”