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Published on: June 12, 2018
Modifying sorbents in controlled release formulations to prevent herbicides pollution
F Flores Céspedes1, M Villafranca Sánchez, S Pérez García
1Department of Inorganic Chemistry, University of Almería, La Cañada de San Urbano, s/n, Almería 04120, Spain.
Chemosphere
|June 26, 2007
Summary
Alginate granules with sorbents like activated carbon effectively controlled the release of herbicides chloridazon and metribuzin. Sorbent addition significantly reduced herbicide release rates, with activated carbon showing the greatest effect.
Area of Science:
- Environmental Chemistry
- Materials Science
- Agricultural Science
Background:
- Herbicides chloridazon and metribuzin are identified groundwater pollutants.
- Controlled release formulations are needed to mitigate environmental contamination.
- Alginate-based granules offer potential for controlled herbicide delivery.
Purpose of the Study:
- To develop alginate-based granules for controlled release of chloridazon and metribuzin.
- To investigate the impact of sorbents (bentonite, anthracite, activated carbon) on encapsulation and release kinetics.
- To evaluate the sorption behavior of herbicides with selected sorbents.
Main Methods:
- Incorporation of herbicides into alginate-based granules with various sorbents.
- Water release kinetic tests to determine release rates and mechanisms.
- Sorption studies to quantify herbicide-sorbent interactions.
- Analysis of water uptake, permeability, and time to 50% release (T50).
Main Results:
- Sorbents significantly reduced the release rate of both chloridazon and metribuzin compared to formulations without sorbents.
- Activated carbon demonstrated the highest efficacy in decreasing herbicide release rates.
- Herbicide release followed a diffusion-controlled mechanism, influenced by sorbent sorption capacity.
- Metribuzin exhibited a higher release rate than chloridazon due to its greater water solubility.
Conclusions:
- Alginate-based granules incorporating sorbents, particularly activated carbon, are effective for controlling the release of chloridazon and metribuzin.
- Sorbent sorption capacity is the primary factor modulating herbicide release from these formulations.
- This approach offers a promising strategy for reducing the environmental impact of these herbicides.
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