UPSC Express

In focus: The magic biopolymer gel

• The magic biopolymer was made by chemically treating ‘chitosan’, which is a natural biopolymer.
• Chitosan is a polysaccharide present in chitins of organisms such as shrimp.
• The chemically fabricated biopolymer gel can switch from being water-repelling in air and oil-repelling under water.
• This is the first time that a material is made switchable, from superhydrophobic to superoleophobic.
• As a result it can be used to separate oil or water from oil-water mixture.
• Besides the gel can be used to separate various oil-water mixtures of different densities of oil such as crude oil, kerosene, motor oil, olive oil etc.

Solution for oil spills

• Due to switchable water-repelling and oil-repelling property the biopolymer gel can be used in oil spills both large scale and small scale.
• Land-based oil spill: In case of small-scale oil spill such as that on land, the gel can made water-repelling so that it can collect the oil.
• Water-based oil spill: In case of large-scale oil spill, the gel can be made oil-repelling so that it can collect and remove water.

About Oil Spills

• Oil Spill is basically leakage of oil and its products in the environment.
• While oil spills are catastrophic when they occur in water, they can severely affect the environment when they occur on land too.
• In water, the major oil spills occur due to accidents, release of crude oil from tankers, refuse of waste oil offshore, drilling rigs etc
• Land-based oil spills occur due to leakage in tankers, vehicles etc.

Major Oil spills

• Recent events of major oil spills include
  • Deepwater Horizon oil spill in Gulf of Mexico. (2010)
  • Exon Valdez oil spill in Alaska (1989)
  • Gulf war oil spill in Kuwait (1991)
  • 2014 Sundarbans oil spill in Shela River in Bangladesh Sundarbans.
  • 2017 Ennore oil spill in Kamarajar Port near Chennai.

Harmful effects

• Oil spills cause severe mortality among seabirds.
• The feathers of the seabird is significantly affects by oil thereby reducing their insulating ability and less buoyant in the water.
• Oil during oil spills is consumed by planktons and bio-accumulate the entire marine food chain including fish, crabs and other aquatic animals.
• Other marine mammals exposed to oil spill get severely affected in terms of insulating property.
• Land-based oil spill cause soil and water pollution
• Sunderban oil spill have severely affected the mangrove forests.

Bio-remediation

• Bioremediation is the use of microorganisms to metabolize and remove oil during oil spills.
• The bacteria used for bio-remediation could include sulfate-reducing bacteria, acid-producing anaerobic bacteria etc.

Advantage of biopolymer gel over bioremediation

• While bioremediation is seen as a solution for oil spill, it significantly changes the ecology of the marine environment.
• Anaerobic bacteria used in bioremediation of oil spill replace other aerobic bacteria in the marine ecosystem.
• Besides the efficiency of biopolymer gel in removing oil spills is 95%.
• Therefore the biopolymer gel could be a good solution to bioremediation.