Answer: Using living organisms (bacteria, fungi, plants) to degrade or detoxify pollutants: Pseudomonas degrades hydrocarbons in oil spills; phytoremediation removes heavy metals; mycoremediation degrades persistent organic pollutants.
- A Using mainly largely synthetic chemical agents and industrial solvents to chemically neutralize pollution at the source, with little living biological organism involved in this process in general practice as frequently described
- B Using living organisms (bacteria, fungi, plants) to degrade or detoxify pollutants: Pseudomonas degrades hydrocarbons in oil spills; phytoremediation removes heavy metals; mycoremediation degrades persistent organic pollutants
- C Bioremediation remains, by some accounts, a largely theoretical laboratory concept that has rarely been put into effect at any real-world contamination site anywhere in most textbook accounts during normal conditions
- D Bioremediation techniques have been demonstrably proven effective mainly against pollution found within freshwater bodies and lakes, rarely proving effective in soil or groundwater contexts as generally observed in typical laboratory settings
Correct answer: B. Using living organisms (bacteria, fungi, plants) to degrade or detoxify pollutants: Pseudomonas degrades hydrocarbons in oil spills; phytoremediation removes heavy metals; mycoremediation degrades persistent organic pollutants
Explanation: Bioremediation exploits natural metabolic abilities: (1) Oil spills - Pseudomonas, Alcanivorax degrade hydrocarbons (enhanced by nitrogen/phosphorus addition); (2) Heavy metals - Thlaspi caerulescens accumulates Zn/Cd (phytoremediation); (3) Chlorinated solvents (TCE) - Dehalococcoides bacteria dechlorinate; (4) PAHs - white rot fungi (Phanerochaete chrysosporium); (5) Mine drainage - Acidithiobacillus. Advantages: cheaper than chemical methods, in situ possible, sustainable.
Sunlight passes through the atmosphere and warms the surface; the surface re-radiates this energy as infrared heat, which greenhouse gases (CO₂, CH₄, water vapour) absorb and trap - a naturally beneficial process that intensifies into global warming as gas concentrations rise from human activity.
Concept context
Pollution, global warming, ozone depletion, deforestation, and sustainability. Important for NEET and general awareness.