Bioremediation of Organochlorine Solvents in Groundwater. Institute of Technology, Sligo Department of Environmental Science and Technology By: Leif Barry Edel Kilgallon Breda King Subject: Waste Management Lecturer: Dr. Michael Broaders. INTRODUCTION Organochlorine Compounds.
Institute of Technology, Sligo
Department of Environmental Science and Technology
Subject: Waste Management
Lecturer: Dr. Michael Broaders
All have been manufactured since the 1940s for use as pesticides. They are not safe for household application. They persist in the environment long after initial use.
Chlorinated solvents and their natural transformation products are the most prevalent organic groundwater contaminants.
Consisting of chlorinated alphatic hydrocarbons (CAHs) have been used for:
Degreasing aircraft engines
Dry cleaning clothes
tetrachloroethane is a manufactured chemical that is widely used in the dry cleaning of fabrics,including clothes. tetrachloroethane is found in consumer products including some paints and spot removers, water repellents, brake and wood cleaners, glues and suede protectors.
Other names for tetrachloroethane include perchloroethylene (PERC) and tetrachloroethylene.
In the USA, EPA studies showed that people who wear freshly dry cleaned clothes, such as a jacket and shirt, every week over a 40 year period could inhale enough PERC to measurably increase their risk of cancer by as much as 150 times.
Organochlorine solvents discharged in sufficient quantities may form an immiscible layer separate from the main body of water.
This is because of the
Low solubility of the solvents
And their different characteristics they are:
An aquifer may remain contaminated for hundreds or thousands of years.
Due to low guideline values it may only take a few litres of solvent to contaminat millions of gallons of groundwater.
Contaminant Guideline value (mg/l)
1,2- dichloroethane 10
1,1- dichloroethane 0.3
Guideline value (ug/l)1,2-
Tentative guideline values:
Common acute effects from solvent exposure include:
The right temperature, nutrients, and amount of oxygen must be present in the soil and groundwater.