Decolorization of Direct Red 28 by mixed bacterial culture in an up-flow immobilized bioreactor

Abstract

Aerobic mixed bacterial culture comprised of five isolates (Bacillus vallismortis, B. pumilus, B. cereus, B. subtilis and B. megaterium) identified by 16srDNA analysis was developed from wastewater samples from the aeration tank of an effluent treatment plant of a textile and dyeing industry and evaluated for its ability to decolorize azo dye Direct Red 28 in an up-flow immobilized packed bed bioreactor using marble chips as support matrix. The bioreactor was operated under two parameters: an aeration rate of 0.4 and 0.6 mmol/min at a flow rate of 60, 90 and 120 ml/h, respectively. At a constant aeration rate of 0.4 mmol/min and with flow rates of 60, 90 and 120 ml/h, optimum decolorization of 91, 75 and 72% was observed, while at an aeration rate of 0.6 mmol/min and flow rates of 60, 90 and 120 ml/h, optimum decolorization of 93, 78 and 72% was observed over 10 days. The study concluded that across the two aeration rates and the respective flow rates, the higher aeration rate of 0.6 mmol/min along with a flow rate of 60 ml/h was best suited to decolorize Direct Red 28 in the packed bed bioreactor. Spectral changes of the input and output of the bioreactor by UV-visible spectroscopy indicated decolorization of the dye solution by degradation in addition to the visual observation of the biosorption process.

Bioremediation and Detoxification of Synthetic Wastewater Containing Triarylmethane Dyes by Aeromonas hydrophila Isolated from Industrial Effluent

“…Toxic effect was probably due to inhibition of cellular metabolic activities and cell growth. Several authors have also reported decreasing color removal with increasing dye concentration during decolorization of other dyes by bacteria [22, 36, 37]. …”

“…However, due to operational ease and facile adaptability of microorganisms to a given set of conditions, the biodegradation mechanism is considered efficacious in comparison to biosorption for treatment of dye wastewater [21]. Over the past few decades, numerous microorganisms have been isolated and characterized for degradation of various synthetic dyes, but most of the reports have dealt mainly with decolorization of azo dyes [22–24]. There is a dearth of information regarding the degradation and detoxification of triarylmethane dyes by microbial systems despite their increased use by the textile industry.…”

Isolation, characterization, and decolorization of Disperse Blue 60 by newly isolated bacterial strains from Kashan textile wastewater

“…Also, the inhibition of cell growth and cellular metabolic properties causes toxicity. According to findings from studies on other bacteria and dyes, the decolorization is decreased with the increasing of dye concentration (Jadhav, Jadhav, Kagalkar, & Govindwar, ; Saratale, Saratale, Chang, & Govindwar, ; Tony, Goyal, & Khanna, ).…”

Microbial Degradation of Reactive Orange M2R Dye by an Application of Bacterial Consortium ETL-A: Bioremedial Approach towards Sustainable Environment

“…However, due to operational ease and facile adaptability of microorganisms to a given set of conditions, the biodegradation mechanism is considered efficacious in comparison to biosorption for treatment of dye wastewater [Singh & Arora., 2011]. Over the past few decades, numerous microorganisms have been isolated and characterized for degradation of various synthetic dyes, but most of the reports have dealt mainly with decolorization of azo dyes [Tony et al, 2009, Gou et al, 2009, Telke et al, 2008. In the present study, a consortium was selected from four consortiums isolated from soil and water samples collected from areas of textile dyeing and printing in Ankleshwar, Gujarat, India and its ability to degrade Reactive Orange M2R (ROM2R) a monoazo dye was analyzed.…”