PTCC ۱۰۱۵S strain of Bacillus cereus as an effective medium for removing azo dyes; acid blue ۱۱۳ and acid orange ۷

AbstractBackground: Bio-remediation methods of organic pollutants are promising due to their high efficiency, low cost, and green chemistry. These methods are effective alternatives to traditional elimination methods. Methods: Bacillus cereus PTCC ۱۰۱۵S strain was used to eliminate acid blue ۱۱۳ (AB۱۱۳) and acid orange ۷ (AO۷) from aqueous solutions. The bacteria activated in the Luria Bertani Broth (MILLER) culture medium. The effective parameters such as incubation time and temperature, pH of dye solution, dye concentration, and the bacterial inoculation quantity on decolorization were investigated. Kinetic and thermodynamic studies were done to clarify the different aspects of the introduced method. Also, the reliability of the method to remove studied dyes was investigated in dye factory wastewater samples.Results: The first-order kinetic model was the best model to describe the kinetics of decolorization. The obtained thermodynamic data showed that the elimination process was endothermic (∆H۰ = +۲۹.۰۳, ۳۰.۵۳) while it was spontaneous (∆G۰<۰) for both studied dyes and so entropy change (∆S۰ = +۱۰۹.۶۳, ۱۱۶.۳۲) was an effective force in the decolorization. In optimized conditions Bacillus cereus PTCC ۱۰۱۵S showed high average removal; ۹۸.۵ and ۹۹.۳ % for AB۱۱۳ and AO۷ respectively in dye model solutions. The removal efficiency was more than ۸۵ % for both studied dyes in wastewater spiked samples.Conclusions: The Bacillus cereus PTCC ۱۰۱۵ strain is capable of being exploited in the removal of AB۱۱۳ and AO۷ dye molecules as an affordable and eco-amiable method for the treatment of aqueous samples contaminated with the studied azo dyes.

کلیدواژه ها:

Dye elimination ، Bio-remediation ، Bacterial medium ، Wastewater