A review on the adsorption of diuron, carbaryl, and alachlor using natural and activated clays

Abstract

Pesticides are considered predominant organic pollutants because they are widespread in many ecosystems. Pesticide residues can degrade chemically, physically, and biochemically in nature, but, because of their high stability and, in some cases, water solubility, they continue to persist in the environment. Pesticides have been eliminated from contaminated waters using a variety of methods that fall under the categories of biological, chemical, physical, and physicochemical remediation processes from various types of matrices, including water and soil. Due to their excellent qualities as adsorbents and pesticide transporters, the use of natural soil components such as clays, iron oxides, or humic acid has recently attracted growing interest. Clays have several advantages over other adsorbents, including large specific surface areas due to their small particle size, low cost, and widespread availability. Clay minerals have a great capacity for adsorption due to Coulombic forces and, attributable to their large surface area, van der Waals forces. This review describes historical, current, and emerging techniques and materials to remove the pesticides diuron, carbaryl, and alachlor using clays as adsorbents.

Soil Organic Matter Composition and pH as Factors Affecting Retention of Carbaryl, Carbofuran and Metolachlor in Soil

“…This is in accordance with the study of Singh et al [ 70 ], who found that carbofuran adsorption was strongly correlated with clay content followed by the organic matter content of soils. However, insecticide uptake on the loam soil material was attributed solely to montmorillonite, presumably due to the enhanced physical diffusion of the pesticide into Mt interlayers, governed by van der Waals forces [ 71 ]. It is commonly observed that the particulate organic (or organo-mineral) soil fractions form stable microaggregates where the retention of pesticides could depend more on steric factors and diffusion mechanisms than on the type and amounts of oxygen-containing functional groups [ 72 ].…”

Multicomponent Adsorption of Pollutants from Wastewater Using Low-Cost Eco-Friendly Iron-Modified Rice Husk Biochar in the Era of Green Chemistry

“…The lower Qmax values may have been due to the competition between aldrin and the other ions for adsorption sites on the surface, resulting in reduced adsorption of Hg 2+ , Pb 2+ , and Cd 2+ (Figure 3). The dimensionless equilibrium (R L ) parameter was close to unity for most of the binary combinations, indicating a favorable adsorption process [36]. The quaternary combinations showed favorable adsorption with R L values less than one (Table 4).…”