Physical characteristics of adsorption–desorption of Fipronil in the soil

Abstract

The adsorption-desorption processes of Fipronil have been performed by using batch equilibrium experiments on eight agricultural soils samples from different locations in south of Iraq, Nasiriya, Amara, and mostly Basrah soils. The kinetics study for adsorption-desorption processes proved that first order rate law is ogled. Thermodynamic parameters (ΔG⁰, ΔH⁰ and ΔS⁰) were also calculated for adsorption process of Fipronil at 288.15, 298.15, and 308.15 K. The negative values for each of ΔG⁰, ΔH⁰ and ΔS⁰ parameters confirmed that Fipronil adsorption processes are high at lower temperature and done via enthalpy effect. The effect of organic matter and clay content on the adsorption of Fipronil in soil samples was studied. Also the adsorption effect caused by surfactants like cationic polyacrylamide (PAM), anionic polyacrylic acid (PAA), and nonionic polyvinyl alcohol (PVA) on the solid liquid interface was investigated. Batch adsorption technique was employed for the metal ions adsorption in soils. The amount of metal ions adsorbed increased with time. Copper ion has more adsorption rates than nickel and iron ions.

Keywords: Ethoxylated polyalkylphenol formaldehyde, jet fuel A1, freezing point, electrical conductivity, density, calorific values, emulsion stability.