Influence of surfactants on leaching of atrazine through soil columns

Abstract

Laboratory experiments were conducted to examine the effect of surfactants, two non‐ionic and one anionic commonly used in detergents, on transport of atrazine through loam and sandy loam soils under saturated conditions. The moment techniques have been used to quantify the effects of surfactants on the mass of atrazine leached, mean time of elution, dispersion and skewness of atrazine breakthrough. Results indicated that application of the anionic surfactant had a dramatic impact on atrazine movement through both soils. The anionic surfactant decreased the amount of atrazine leached from 78% in deionized water to 52% for Elora loam and from 75% to only 13% in sandy soil, respectively. Land application of anionic surfactant also increased the mean time of elution by 142% and 431% compared to deionized water for loam and sandy loam soils, respectively. However, application of non‐ionic surfactants increases atrazine leaching. The percentage of atrazine eluted in the presence of Rexonic at 3000 mg/L and 200 mg/L and Rexol at 200 mg/L were 87%, 80% and 84%, respectively compared to only 76% in deionized water. Results also indicated that application of surfactants results in a physio‐chemical changes in soil matrix that affects atrazine sorption. Non‐equilibrium conditions seemed to govern atrazine movement in the presence of surfactants as noticed from the long tailing and double peaks in the breakthrough curves.