Crop-Derived Biochar for Removal of Alachlor from Water

Area of Science:

• Environmental Chemistry
• Water Treatment Technologies
• Materials Science

Background:

• Pesticide contamination in water poses significant environmental and health risks due to high toxicity.
• Conventional water treatment methods can be costly and less effective for removing specific pollutants.
• Biochar derived from agricultural waste offers a promising, cost-effective adsorbent for pollutant removal.

Purpose of the Study:

• To evaluate the efficacy of wheat grain biochar as an adsorbent for removing the pesticide alachlor from water.
• To investigate the sorption properties and removal mechanisms of biochar for alachlor.
• To determine the optimal conditions and capacity for alachlor adsorption by biochar.

Main Methods:

• Preparation of biochar from wheat grains.
• Batch experiments to study the adsorption of alachlor onto biochar at varying initial concentrations.
• Kinetic and isotherm modeling (pseudo-second-order and Langmuir models) to understand adsorption behavior.
• Characterization of biochar properties (micropores, surface functional groups).

Main Results:

• Wheat grain biochar demonstrated significant removal of alachlor, ranging from 76% to 94%.
• Maximum alachlor removal (94%) was achieved at an initial concentration of 1 mg/L.
• Adsorption kinetics followed the pseudo-second-order model (R² = 0.999), and equilibrium data fitted the Langmuir isotherm model (R² = 0.996).
• The maximum adsorption capacity of the biochar for alachlor was determined to be 1.94 mg/g.

Conclusions:

• Wheat grain biochar is an effective and efficient adsorbent for removing alachlor from contaminated water.
• The adsorption process is well-described by pseudo-second-order kinetics and the Langmuir isotherm, indicating chemisorption is likely involved.
• The microporous structure and surface functional groups of the biochar contribute to its high adsorption capacity for alachlor, suggesting its potential for environmental remediation.