Response surface methodology for cadmium biosorption on Pseudomonas aeruginosa

Area of Science:

• Environmental Science
• Biotechnology
• Chemical Engineering

Background:

• Cadmium (Cd2+) is a toxic heavy metal pollutant.
• Biosorption offers a sustainable method for heavy metal removal.
• Pseudomonas aeruginosa is a potential biosorbent material.

Purpose of the Study:

• To investigate the biosorption of Cd2+ by Pseudomonas aeruginosa.
• To determine the effects of physicochemical factors on Cd2+ uptake.
• To analyze the thermodynamic and kinetic properties of the biosorption process.

Main Methods:

• Studied effects of initial metal concentration, pH, and contact time.
• Applied Langmuir adsorption isotherm model.
• Utilized response surface methodology (RSM) for optimization.
• Analyzed thermodynamic parameters (ΔG(0), ΔH(0), ΔS(0)) at varying temperatures.

Main Results:

• Equilibrium time for Cd2+ biosorption by P. aeruginosa was approximately 5 minutes.
• Langmuir equation accurately described adsorption equilibrium data.
• Maximum biosorption capacity was extrapolated to 0.56 mmol/g.
• Biosorption is a spontaneous and endothermic process (ΔH = 36.35 J/mol).
• RSM quadratic model showed high accuracy (R² = 0.98).
• Optimal conditions: 0.5 g/L biosorbent, pH 6, 30°C.

Conclusions:

• P. aeruginosa is an efficient biosorbent for Cd2+ removal.
• Physicochemical factors significantly influence biosorption efficiency.
• The process is thermodynamically favorable and spontaneous.
• Identified optimal conditions provide a basis for practical application in wastewater treatment.