Optimization of effective environmental parameters on Astrazon Red GTL removal by dominant species Bacillus and Aeromonas: in a concurrent culture study

Astrazon Red GTL is one of chemical dyes that vastly used in various industries. According to effects of this dye, degradation of wastewater containing Astrazon Red GTL is vital. According to previous researches, suspended microorganisms reactor is one of economically methods. suspended biofilm microorganisms reactor can reach to optimal efficiency in suitable retention time. In this research, for the first time, two cylindrical reactor was used and a new reactor was designed and called as “circulating feed biofilm reactor”. Every of these cylindrical reactors had 2.75 litter volume, 10 cm area and 35 cm height. In this research “circulating feed biofilm reactor” was used for growing of mixed culture microorganism containing Bacillus and Aeromonas. This reactor was used for treatment of Astrazon Red GTL wastewater. In “circulating feed reactor”, two independent variables including retention time and input concentration of pollutant were measured and the effect of each variable were studied on the removal percentage of dye. Following that, modeling and determining the optimum conditions for operating the FB/FFMBBR was carried out based on Response Surface Methodology (RSM). The results showed that the optimum condition occurred at retention time of 6.21 h and input dye concentration of 74.77 mg/l. Based on this research, retention time has the greatest impact on the removal efficacy of this biological system.