טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentMarek Orly
SubjectComparative Study of Soil Bioremediation by Internal and
External in Situ Treatment
DepartmentDepartment of Civil and Environmental Engineering
Supervisor Professor Emeritus Noah Galil (Deceased)


Abstract

The contamination of the under-ground and the groundwater caused by fuels which origin from NAPL is a growing global problem. These fuels contain dangerous chemical compounds and if found in groundwater it will be revoked as supply water. One of the technologies to remove the NAPL pollution is biological degradation also known as bioremediation.

The bioremediation process uses microorganism that are found in the ground to eliminate organic pollutants. In order to encourage this microbial activity, addition of electrons acceptor as well as nutrients and microelements are required.

    The purpose of this research was to examine three different approaches for bioremediation, using a typical petrochemical pollutant - kerosene.
  1. Biological degradation in the ground.
  2. Biological degradation using trickling filter above ground.
  3. Biological degradation using external biological treatment.

This research examined the effectivity of the pollutants decompositions in terms of biodegradation rate and determines which is the most efficient method.


Three subsystems were operated under saturated flow conditions and a steady head of water above bed. Each column was polluted on separate events. The systems were operated continuously for 7 months and different parameters were measured at different time intervals in order to monitor the changes of the water quality and of the progress of the biodegradation.

Additional experiments were carried out in batch systems and investigated adsorption and evaporation mechanisms. Flow measurements were performed as an indication for hydraulic conductivity of the columns.

All parameters show a clear advantage to the combination of external and internal ground treatment. Nutrients consumption, kerosene removal and biosolids accumulation clearly indicate advantage for system no.3 in which intensive external biotreatment was combined with insitu treatment.