Crude oil removal from aqueous solution using raw and carbonized Xanthoceras sorbifolia shells

Area of Science:

• Environmental Science
• Materials Science
• Chemical Engineering

Background:

• Crude oil contamination in aqueous solutions poses significant environmental risks.
• Development of cost-effective and sustainable biosorbents is crucial for remediation.
• Agricultural residues offer a promising source for novel adsorbent materials.

Purpose of the Study:

• To investigate Xanthoceras sorbifolia (X. sorbifolia) fruit shell as a biosorbent for crude oil removal.
• To compare the efficacy of raw and carbonized X. sorbifolia shell.
• To optimize adsorption conditions and elucidate the sorption mechanism.

Main Methods:

• Characterization of raw and carbonized X. sorbifolia shell using SEM and FTIR.
• Batch adsorption experiments to evaluate oil removal capacity.
• Orthogonal experimental design for optimization of adsorption parameters.
• Kinetic modeling to describe the adsorption process.

Main Results:

• Raw X. sorbifolia shell exhibited a higher crude oil removal capacity (75.1 mg g⁻¹) than carbonized material (49.5 mg g⁻¹).
• Saponin content in raw shell positively correlated with oil removal, indicating its role in adsorption.
• Optimized conditions achieved high removal efficiency using 4 g L⁻¹ raw shell (<0.15 mm), 400 mg L⁻¹ initial oil concentration, 30°C, 10 min, and 150 rpm.
• Adsorption followed a pseudo-second-order kinetic model.

Conclusions:

• Raw X. sorbifolia shell is a highly effective and low-cost biosorbent for crude oil removal from aqueous solutions.
• The presence of saponins and their functional groups significantly contributes to the biosorbent's efficacy.
• Agricultural residues like X. sorbifolia shell can be utilized directly as biosorbents, reducing the need for energy-intensive processing.