Question

Match List I with List II which contain water pollutants and their sources respectively 

List I	List II
Water pollutants	Sources
A. Oxygen demanding wastes	I. Mine drainage
B. Plant nutrients	II. Modern washing powders and agriculture run-off
C. Acids	III. Waste incineration and toxic dumps
D. Polychlorinated biphenyls (PCBs)	IV. Paper mills and food processing units

Choose the correct answer from the options given below:

1. A - IV, B - III, C - II, D - I
2. A - IV, B - I, C - III, D - II
3. A - IV, B - II, C - I, D - III
4. A - IV, B - III, C - I, D - II

Answer 1

Correct Answer - Option 3 : A - IV, B - II, C - I, D - III

Below is the explanation of the correct answer:

List I	List II
Water pollutants	Sources
A. Oxygen demanding wastes	Wastewater generated from paper mills, food production, and agricultural activities is a major source of environmental pollution. It is also among the most difficult and costly waste to manage because food processing wastewater can contain large quantities of nutrients, organic carbon, nitrogenous organics, inorganics, suspended and dissolved solids, and it has high biochemical and chemical oxygen demands. It must be treated to levels that will not damage receiving waters due to excessive nutrients or oxygen demand when directly discharged or will not disrupt publicly owned treatment works (POTWs) when discharged to sewers.
B. Plant nutrients	Greywater (water from your bathroom sinks, showers, tubs, and washing machines) is considered a valuable resource with a high reuse potential for irrigation of household lawns and gardens. However, there are possibilities of surfactant and sodium accumulation in soil from the reuse of greywater which may affect agricultural productivity and environmental sustainability adversely.
C. Acids	Acid mine drainage, acid and metalliferous drainage (AMD), or acid rock drainage (ARD) is the outflow of acidic water from metal mines or coal mines. Acid mine drainage is the formation and movement of highly acidic water rich in heavy metals. This acidic water forms through the chemical reaction of surface water (rainwater, snowmelt, pond water) and shallow subsurface water with rocks that contain sulfur-bearing minerals, resulting in sulfuric acid.
D. Polychlorinated biphenyls (PCBs)	PCBs are a group of more than 200 similar manmade chemicals. They are oily liquids or solids, clear to yellow in colour, with no smell or taste. PCBs are found as mixtures and are very stable and resistant to extreme temperature and pressure. Incineration is generally considered to be the preferred method of disposal for PCB waste with > 50 ppm of PCBs.

Therefore, option 3 is the correct answer.