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.

This study evaluates and compares the adsorptive properties of four natural clays from Albania regions: Brari, Currila, Dardha and Prrenjasi, in regards to the adsorption of two insecticides, dimethoate and methomyl, from their aqueous solutions. Special studies on the adsorption of these two insecticides have been previously published by authors, [45], [58], [59], and [60] while this research is focused on the comparison of the adsorbent properties of the four above mentioned clays based on the obtained experimental results. Dimethoate adsorption was performed at T=25

Desorption of some insecticides used in agriculture from natural Albanian clays impregnated with these insecticides is evaluated in this study. There are well-known compounds in this field such as: Dimethoate, Methomyl, Metribuzin and 2-4-D which have been studied as insecticides. The study was performed using natural clays selected from the regions of Brari, Currila, Dardha and Prrenjasi, which have been used in parallel for other studies in the field of adsorption of insecticides through natural clays. In the course study the clays were impregnated with insecticides with a concentration of 1mg/g of clay -calculated as pure insecticide, while the desorption process was investigated from 2 hours to 24 hours and in special cases up to 48 hours. It has been noticed that the insecticides desorption from clays occurred fast, within the first few hours. Most of the insecticides are transferred into the water, with the exception of 2,4-D which desorbs slowly and for 48 hours reaches a desorption rate of 27%. Based on the studied desorption process of the selected insecticides from the natural clays, it is possible to impregnate clays with different insecticides with well-calculated concentrations and use these clays in agriculture to combat crop damage. In this way the quantities of released insecticides are completely controlled and do not create environmental pollution. The use of natural clays as adsorbants/desorbants presents an effective formulation in combating crop damage. Since the insecticides desorption from clays requires a certain time, their aimed activity is prolonged whilst causing less damage on the agricultural crops.