Bioremediation for Oil-Contaminated Sites
Bioremediation of crude oil contaminated sites has become possible in India today because of TERI'S Oilzapper, a crude oil degrading bacterial system that has been developed to reclaim contaminated sites. Oil spills frequently pose a major threat to the environment. Crude oil being lighter than water floats on the water surface, thus, also posing the grave threat of fire hazard.
On land, crude oil is transported through pipelines to various locations, where they are processed. There have been instances when these pipelines have been damaged and large quantities of oil discharged in to open fields.On land, oil spills generally pose three types of hazards. These are: Fire, Ground water pollution and Air pollution due to evaporation.
Bioremediation consists of using biological organisms, usually bacteria, fungi, and to a lesser extent, plants, to reduce or eliminate toxic pollutants. These organisms either eat up the contaminants or assimilate within themselves all harmful compounds in the surrounding area, thereby, rendering the region pollution-free. However, there are situations where the native bacterial population is insufficient to remove pollutants quickly. It has been found that in such situations, biodegradation proceeds at a faster rate when the site is augmented with a species known to meat up these pollutants. This process is known as bioaugmentation.
In India, petroleum refining is being carried out at various geo-climatic locations. These sites produce enormous quantities of oily sludge--a waste, which is generated after crude oil is refined. TERI has a ready stock of bacteria obtained from the natural environment that eat up the harmful compounds in oil spill sites. These bacteria are multiplied under laboratory conditions and are mixed with specific carrier material and packed in polybags for easily transportation to various locations. TERI has named these carrier-based bacteria Oilzapper.
Oilzapper: culture of oil-degrading bacteria-ready to use
Oilzapper was applied at the Mathura refinery over a small area on an experimental basis and following encouraging results obtained there, a larger area, covering about three acres of land. A similar activity has also been undertaken at the Barauni oil refinery.
- Eco-friendly diesel-alcohol fuel mix may get nod
The Union Ministry of Environment and Forests is actively considering the proposal of All India Distiller's Association (AIDA) to make mandatory the use of alcohol or ethanol as an oxygenate in admixture with gasoline or diesel fuel.
AIDA has stated that India has already developed an installed capacity for production of 2,825 million litters of alcohol per year. A major part of the installed capacity has remained under utilised which can be advantageously utilised by producing the required quantity of alcohol for being used as oxygenate in flues in automobiles.
AIDA has further stated that it is universally accepted that the utilisation of ethanol-gasoline blends substantially reduces the harmful emissions of volatile organic compounds, hydrocarbons, oxides of nitrogen, suspended particulate matter, sulphur dioxide and carbon monoxide. Three types of oxygenates are used in different parts of the world namely MTBE, ETBE and ethanol. Ethanol is considered to be best as it is also an octane booster. A large number of distilleries in eight states have already offered to supply 498.8 million litre of anhydrous alcohol (i.e. ethanol with minimum purity of 99.5 percent) at Rs.18.58 per bulk litre. Ethanol blends are in use in a number of European and South American countries, particularly Brazil and US.
AIDA stated that gasoline-alcohol blend in cars is not a new concept to India. During the Second World War in 1940s when petrol became scare, the use of gasoline-alcohol blend was continued till long after the war.
- Pollution control board plans to introduce cleaner fuel
Not satisfied with unleaded fuel to solve pollution-related problems, the Central Pollution Control Board (CPCB) wants to go a step forward and introduce cleaner fuel.
The cleaner fuel would have lower quantities of sulphur, benzene and aromatic content and would therefore be less polluting. The Board plans to implement it all over India by 2005. Though the production cost of this fuel will increase, CPCB is optimistic the proposal will go through, considering the health benefits involved. The norms would apply to all refineries in the country.
Benzene levels in petrol would go down from 3 percent to 1 percent; sulphur would be reduced from 0.20 percent to 0.10 percent and the aromatic content, which leads to hydrocarbon emission, would go down 45 percent to 30 percent. Similarly, CPCB proposes the sulphur levels in diesel be reduced from 0.25 percent to 0.05 percent. This cleaner fuel, says will increase the life of catalytic converters.