Modern Chemistry & Applications

Dechlorination of pesticides in water using Fe-Pd bimetallic nanoparticles on membrane composite

International Conference on Applied Chemistry

October 17-18, 2016 Houston, USA

Jane Catherine Ngila and Nthumbi R M

University of Johannesburg, South Africa

Scientific Tracks Abstracts: Mod Chem appl

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/MSg- 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.

Biography :

Jane Catherine Ngila has a Bed (Sci) and MSc (Chemistry) from Kenyatta University (KU), Kenya (1986 and 1992) and PhD from UNSW Australia (1996). She worked as a tutorial fellow/Lecturer at KU from 1989-1997 and as a Lecturer/Senior Lecturer from 1998-2006 at University of Botswana. She also worked as Senior Lecturer from 2006-2011 at University of KwaZulu Natal and as Professor of Chemistry at University of Johannesburg (UJ) in April 2011. She has taught various courses in Analytical/Environmental Chemistry and research in water quality monitoring and treatment using nanocomposite membranes; modelling mass balance in wastewater treatment plants. She has published more than 100 journal articles and graduated more than 50 postgraduate students.

Email: jcngila@uj.ac.za