Environmental factors
organic matter (source of carbon and energy)
oxygen availability
nutrient (N,S, P) availability
temperature
pH
Eh
salinity
water activity
The addition of nutrients and electron acceptors
Stimulate activities that promote degradation of pollutant by the indigenous or existing microbial populations in the contaminated area
The addition of specific metabolic ca
Shortcomings of current process
1. Activated carbon adsorption
2. Direct combustion
3. Catalytic oxidation
4. Ozone oxidation
1. Inconsistent efficiency
Efficiency sharply drops when it works for long time.
It happens as nutrients for microorganisms are insufficient.
2. Unequal growth of microorganisms
Efficiency decreases, hard to handle when factors change suddenly
military base
Layer : contaminated layer on the ground
water surface
Concentration reductions and constituent concentrations are difficult to achieve.
May not be effective for high constituent concentrations
Presence of significant heavy metal concentrations may inhibit microbial growth.
Volatile constituents tend to evaporate
Requires a large land area
contaminant in groundwater not only in Korea, also in many parts of the world today.
When nitrate in ground water is discharged to river or ocean, it can also cause eutrophication in water body.
Nitrate is converted to nitrogen gas by microbial reduction.
It can also be reduced to nitrite and nitrous oxide gas by abiotic reactions, but in the subsurface these reactions are minor compared to bio
microbial control in food, irradiation is an effective alternative to protect food against insect damage and as a quarantine treatment of fresh produce.
The FAO has estimated that worldwide about 25% of all food production is lost to insects, bacteria and rodents after harvesting. The use of irradiation alone as a preservation technique will not solve all the problems of post-harvest food losses