Optimization and characterization of Congo red dye biosorption by Serratia marcescens MM06

Dyes, toxic and carcinogenic substances, have detrimental effects on the environment and human health when present in wastewater. Biosorption is the most effective and versatile method for removing dye from wastewater since it is highly efficient and cost- effective. The impact of dye pollution has been felt in many countries, including Malaysia. Dye is a frequent pollutant found in water that can come from a variety of places, including manufacturing companies, research centres, and medical centers. Dye pollution has major negative consequences on both the environment and human health. The purpose of the research is to investigate the efficacy of bacterial biomass biosorption of Congo red dye for industrial applications. The objectives of this study are to: (a) screen and optimize the bacterial sorption of Congo red dye using one factor at a time (OFAT) and response surface methodology (RSM); (b) conduct Fourier Transform Infrared (FTIR), scanning electron microscope (SEM), and energy dispersive x-ray (EDX) analysis; (c) determine the kinetics and equilibrium model for Congo red dye biosorption; and (d) study the thermodynamics of Congo red dye biosorption. Numerous bacterial isolates from twelve (12) different species were tested against Congo red. The amount of dye removed from Serratia marcescens strain MM06 biomass was found to be greater compared to the other 11 bacterial isolates. The biomass was incubated with a known dye concentration (100 ppm), centrifuged, and the absorbance was measured at 507 nm. The results were investigated under various biosorption conditions, including agitation, dye concentrations, time, temperature, and pH. The optimal conditions for dye removal were determined to be 90 mg/L dye concentration, 125 rpm agitation, 20 minutes contact time, pH 7.0, and 25 °C, resulting in 91.75% Congo red dye removal. The biosorption process was characterized and confirmed using FTIR analysis. Using this approach, the functional groups involved in the biosorption of congo red dye were thoroughly studied, and include alkyl, hydroxyl, amide, and thiol. SEM was used to examine the surface morphology of the biomass before and after adsorption, and it revealed the presence of macro-pores on the surface that were unevenly distributed smoothly and tightly, and that these macro-pores improved the adsorption of Congo red dye molecules onto the surface of Serratia marcescens strain MM06. Because of the material's porosity and the electrostatic interaction between the biosorbent and the Congo red dye, the physical adsorption process was found to predominate based on SEM and FTIR analysis. In the EDX study, various components from biomass were detected by the EDX spectrum before and after biosorption. C, O, P, and S were found, and elemental analysis revealed that C (53.44% and 69.63%) and O (79.96% and 28.17%) had the largest percentages before and after dye treatment, respectively. Nonlinear regression was employed to study biosorption isotherms, kinetics, and finally thermodynamic parameters. Pseudo-second order kinetics and the Langmuir isotherm best describe the biosorption process. In the Isotherms investigations, all eight of the Isotherm models tested on the dye (Henry, Langmuir, Freundlich, BET, Toth, Sips, Fritz-Schlunder IV, and Fritz-Schlunder V), with the exception of the Henry and Toth model, yielded a satisfactory fitting result. The parameters of the fitted isotherms, namely, Langmuir, Freundlich, BET, Sips, Fritz-Schlunder IV, and Fritz-Schlunder V were 4.387657 mg/g, 3.750862 mg/g, 4.387657 mg/g, 2.800659 mg/g, 12.178957 mg/g, 2.557313 mg/g respectively. The parameters of thermodynamics Gibbs free energy (DG◦), enthalpy (DH◦), and entropy (DS◦) changes showed that the biosorption process was exothermic and spontaneous. Based on the findings, Congo red dye can be removed from wastewater effluent using Serratia marcescens mm06 as biosorbent.

Text FBSB 2023 10 - Full Text.pdf Available under License Creative Commons Attribution Non-commercial No Derivatives. Download (6MB) Text FBSB 2023 10.pdf Restricted to Repository staff only Available under License Creative Commons Attribution Non-commercial No Derivatives. Download (7MB)

Actions (login required)

View Item