Research School for Socio-Economic and
Natural Sciences of the Environment
Research School for Socio-Economic and
Natural Sciences of the Environment

Shrutika Wadgaonkar

Date: 18 December 2017
Time: 15:30 - 16:30
Location: IHE Delft Auditorium A1b, Westvest 7, 2611 AX, Delft

Dissertation title: 

Novel bioremediation processes for treatment of seleniferous soils and sediment

Group: IHE Delft, Pollution Prevention and Control
Promotor: Professor Piet Lens
Copromotors: Prof.dr. Eric van Hullebusch, Prof.dr. Giovanni Esposito, Dr. Yarlagadda Nancharaiah


The aim of this Ph.D. was to develop a technology for the remediation of seleniferous soils/sediments and to explore microbial reduction of selenium oxyanions under different respiration conditions and bioreactor configurations. Seleniferous soil collected from the wheat-grown agricultural land in Punjab (India) was characterized and its soil washing was optimized by varying parameters such as reaction time, temperature, pH and liquid to solid ratio. The effect of competing ions and oxidizing agents as chemical extractants for soil washing were also studied. Soil leachate containing selenium oxyanions obtained from soil washing was treated in a UASB reactor by varying the organic feed. Moreover, ex situ bioremediation of selenium oxyanions was studied under variable conditions. An aerobic bacterium capable of transforming selenate and selenite to elemental selenium, anaerobic bioreduction of selenate coupled to methane as electron donor and the effect of contamination of other chalcogen oxyanions in addition to selenium was studied.