Jane Catherine Ngila
University of Johannesburg, South Africa
Title: Dechlorination of pesticides in water using Fe-Pd bimetallic nanoparticles on membrane composite
Biography
Biography: Jane Catherine Ngila
Abstract
We report dechlorination of mixed pesticides (dieldrin, chlorpyrifos, diuron and fipronil) using Fe-Pd nanoparticles anchored on acrylic acid (AA) grafted mesoporous silica (MS) membrane as inert support designated as (Fe-Pd/MS-g-PAA). Nanocomposites made up of inorganic nanoparticles give enhanced performance due to their high surface area to volume ratio. When Fe-Pd is loaded on MS-g-PAA substrate, the costly post-treatment and filtration processes associated with powdered materials are eliminated. Chlorinated pesticides are manufactured in large quantities primarily for eradication of pests in agriculture. However, they finally end up in our soils, food and water sources. These pesticides are cholinesterase inhibitors and their adverse health effects manifest in the nervous, immune and endocrine systems. Therefore, their removal from contaminated water is necessary. Bimetallic iron-palladium nanoparticles immobilized on MS-g-PAA were used for their dechlorination to benign products. The loading of Fe-Pd was done by adding 1 g MS-g-PAA to a ferrous sulfate solution followed by reduction with NaBH4. The precipitate was then added to palladium acetate solution, reduced, filtered, washed and dried. The composite was characterized using FTIR, XRD, SEM, BET and TEM and chemical analysis was done using GCxGC-TOFMS. The results obtained show that 95 to 99 % of dieldrin, chlorpyrifos and diuron were dechlorinated in 60, 120 and 180 minutes respectively, while for fipronil, it took 180 minutes to reach 90%. The data was processed to obtain kinetic parameters. However, mineralization rate (mr) was low at 36 %, 45 %, 43 % and 45% for chlorpyrifos and dieldin, fipronil and diuron, respectively.