Remediation of oil-polluted soil using anionic and non-ionic composite biosurfactants

Area of Science:

• Environmental Science
• Soil Remediation
• Green Chemistry

Background:

• Petroleum hydrocarbons contaminate soil, posing risks to ecosystems and health.
• Surfactant washing is effective for hydrocarbon remediation, but biosurfactants are costly.
• Biosurfactants offer environmental compatibility, driving interest in their application.

Purpose of the Study:

• To develop a cost-effective cleaning agent for petroleum-contaminated soil using biosurfactants.
• To optimize a novel cleaning agent formula through compounding and additive selection.
• To evaluate the efficiency of the developed biosurfactant system for soil remediation.

Main Methods:

• Selected β-cyclodextrin (C1) and sodium carboxymethyl cellulose (C2) as biosurfactants.
• Developed a cleaning agent formula by compounding C1 and C2 with sodium humate and sodium carbonate.
• Optimized oil washing parameters including temperature, pH, time, solid-liquid ratio, and oscillation frequency.

Main Results:

• An optimal C1:C2 volume ratio of 8:2 with 8 g/L electrolyte mixture minimized surface tension and maximized oil removal.
• Synergistic behavior of mixed micelles was explained using ideal solution theory and the Rubingh model.
• Optimized conditions yielded a 76% oil removal rate.

Conclusions:

• The developed cleaning agent is cost-effective, easy to apply, and environmentally friendly.
• The agent demonstrates rapid and significant cleaning effects for petroleum-contaminated soil.
• This biosurfactant-based cleaning agent shows promise for field-scale soil purification applications.