Question

Difficulty: HardSoil Pollution, Pesticides, Heavy Metals, and Waste Management

Match each soil pollutant or waste management technique in Column A with its corresponding chemical mechanism, bio-environmental effect, or operational principle in Column B.

  • Arsenic (As\text{As}) contamination in agricultural soilDisruption of cellular respiration by binding to sulfhydryl (SH-\text{SH}) groups of enzymes and chemically mimicking inorganic phosphate ions
  • Organophosphate pesticides (e.g., Parathion, Malathion)Inhibition of acetylcholinesterase enzymes at neuromuscular junctions, possessing shorter environmental persistence than organochlorines
  • Phytoremediation using hyperaccumulating speciesExtraction and bioconcentration of heavy metals or organic contaminants from soil matrices directly into harvestable plant biomass
  • Pyrolysis of non-biodegradable polymeric wasteThermal decomposition of organic and synthetic polymeric materials in the complete absence of oxygen to yield bio-oil, combustible gases, and char

Answer

Arsenic contamination in agricultural soil matches the disruption of cellular respiration by binding to sulfhydryl groups and mimicking phosphate ions. Organophosphate pesticides match the inhibition of acetylcholinesterase enzymes with shorter environmental persistence. Phytoremediation matches the extraction and bioconcentration of soil heavy metals into plant biomass. Pyrolysis matches thermal decomposition in the absence of oxygen to produce bio-oil, gases, and char.
Each soil contaminant and waste treatment procedure is correctly linked to its fundamental biochemical pathway or thermodynamic condition: Arsenic disrupts sulfhydryl enzymes and phosphate pathways; Organophosphates selectively inhibit acetylcholinesterase; Phytoremediation relies on plant bioaccumulation of soil metals; and Pyrolysis achieves thermal decomposition under anaerobic conditions.

Step-by-Step Solution

1
Analyze the biochemical toxicity mechanism of Arsenic
Arsenic (As\text{As}) forms covalent bonds with enzyme sulfhydryl (SH-\text{SH}) groups and acts as a structural analog to phosphate, inhibiting ATP synthesis.
Heavy metals disrupt metabolic pathways by binding to functional group residues on key metabolic enzymes.
2
Examine the mode of action and biodegradability of Organophosphates
Organophosphates inhibit acetylcholinesterase, leading to acetylcholine buildup. They are biodegradable compared to persistent chlorinated hydrocarbons like DDT.
Synthetic pesticide classification relies on chemical structure, biological targets, and environmental degradation rates.
3
Identify the eco-friendly soil cleanup method utilizing plants
Phytoremediation uses hyperaccumulators to take up heavy metal pollutants from contaminated ground into plant tissues.
Biological soil remediation relies on bio-uptake processes to remove heavy metals without chemical soil destruction.
4
Distinguish Pyrolysis from other thermal waste treatment methods
Pyrolysis is anaerobic thermal degradation yielding bio-oil, syngas, and char, contrasting with oxygen-rich incineration.
Thermal waste processing methods differ in operating atmosphere (presence vs. absence of O2\text{O}_2) and end-products.

Key Concept

Mechanisms of Soil Pollutants, Agrochemicals, Heavy Metal Toxicity, and Modern Waste Processing Techniques
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