PhD Topic: Geochemical controls on arsenic mobilization, speciation and distribution in alluvial aquifer deposits of Nawalparasi district, Nepal.
Supervisors: Assoc. Prof Scott Johnston, Assoc. Prof Ed Burton & Assoc. Prof Suresh Das Shrestha
MSc, Environmental Sciences, 2010 (Wageningen University)
Research interests / background:
The Terai region of Nepal is the upper part of the Indo-Gangetic plain and is contaminated with high arsenic concentration. Nawalparasi is one of the most As contaminated districts in the Terai region. The sedimentary origins of As and the precise mechanism(s) responsible for As mobilization in alluvial aquifer sediments of the Nawalparasi district are unknown. This PhD study will help to indentify these gaps by conducting an in-depth study of the geochemical characteristics of alluvial aquifer sediments from the Terai region of Nepal. The knowledge gained by this project will make a significant contribution towards the identification of the primary mechanism controlling As-release in the holocene aquifer.
The project has four primary aims:
- Conducting a high-resolution spatial survey of aquifer aqueous geochemistry to examine geochemical evidence for various arsenic mobilisation mechanisms.
- Undertake an in-depth mineralogical characterisation of contrasting aquifer sediments.
- Quantify As sorption behaviour in contrasting aquifer sediments.
- Examine the reductive mobilisation of Arsenic from contrasting natural aquifer sediments.
Johnston S.G., Diwakar J., Burton E.D. (2015) Arsenic solid-phase speciation in an alluvial aquifer system adjacent to the Himalayan forehills, Nepal. Chemical Geology, 419, 55-66.