Aerobic Biodegradation of a Sulfonated Phenylazonaphthol Dye by a Bacterial Community Immobilized in a Multistage Packed-Bed BAC Reactor

Abstract

A microbial community able to aerobically degrade the azo dye Acid Orange 7 was selected from riparian or lacustrine sediments collected at sites receiving textile wastewaters. Three bacterial strains, pertaining to the genera Pseudomonas, Arthrobacter, and Rhizobium, constitute the selected community. The biodegradation of AO7 was carried out in batch-suspended cell culture and in a continuously operated multistage packed-bed BAC reactor. The rapid decolorization observed in batch culture, joined to a delay of about 24 h in COD removal and cell growth, suggests that enzymes involved in biodegradation of the aromatic amines generated after AO7 azo-bond cleavage (1-amino-2-naphthol [1-A2N] and 4-aminobenzenesulfonic acid [4-ABS]), are inducible in this microbial consortium. After this presumptive induction period, the accumulated byproducts, measured through COD, were partially metabolized and transformed in cell mass. At all azo dye loading rates used, complete removal of AO7 and 1-A2N was obtained in the multistage packed-bed BAC reactor (PBR).; however, the overall COD (eta ( COD )) and 4-ABS (eta ( ABS )) removal efficiencies obtained in steady state continuous culture were about 90%. Considering the toxicity of 1-A2N, its complete removal has particular relevance. In the first stages of the packed-bed BAC reactor (Fig. 4a-c), major removal was observed. In the last stage, only a slight removal of COD and 4-ABS was obtained. Comparing to several reported studies, the continuously operated multistage packed-bed BAC reactor showed similar or superior results. In addition, the operation of large-packed-bed BAC reactors could be improved by using several shallow BAC bed stages, because the pressure drop caused by bed compaction of a support material constituted by small and fragile particles can be reduced.

Microbial degradation of microcystin in Florida’s freshwaters

“…are common soil bacteria that form plant nodules and have the enzyme nitrogenase for fixing nitrogen. Biodegradation of sulfonated phenylazonaphthol dye (Ruiz-Arias et al 2010) and phenol (Wei et al 2008) was found to be associated with Rhizobium sp. While Microbacterium sp.…”

Biological approaches to the purification of textile wastewater

“…Ruiz-Arias et al worked on the discoloration of acid orange with the help of a bacterial consortium Pseudomonas, Arthrobacter and Rhizobium. The results showed complete discoloration at a concentration of 200 mg/l, pH 7 [48].…”

“…Such an acid is susceptible to decomposition by the same consortium under aerobic conditions. About 97% decomposition within 24 hours of direct blue dye 15 with a concentration of 250 mg/l (98 COD) is reported by Jain et al and Ruiz-Arias et al worked on the discoloration of acid orange with the help of a bacterial consortium [47,48]. Ruiz-Arias et al worked on the discoloration of acid orange with the help of a bacterial consortium Pseudomonas, Arthrobacter and Rhizobium.…”

Co‐enhanced activated sludge system by static magnetic field and two halotolerant yeasts for azo dye treatment

“…In detail, bacterial genera Rhizobium, Rhodobacter, Altererythrobacter, and Dyella were enriched in the six treated samples. Relevant literatures showed that species belonging to Rhizobium and Rhodobacter could degrade azo dyes and other aromatic compounds (Bin et al, 2004;Huang et al, 2016;Ruiz-Arias et al, 2010;Song, Zhou, Wang, Yan, & Du, 2003). Some of them were even halotolerant species (Diagne et al, 2017;Tangprasittipap, Prasertsan, Choorit, & Sasaki, 2007).…”