Question

The pH of the water sample collected from a river was found to be acidic in the range of $3.5–4.5$, on the banks of the river were several factories that were discharging effluents into the river. The effluents of which one of the following factories is the most likely cause for lowering the pH of river water?

• A. Soap and detergent factory
• B. Lead battery manufacturing factory
• C. Plastic cup manufacturing factory
• D. Alcohol distillery

Answer 1

The correct option is B

Lead battery manufacturing factory

Explanation for correct option

(B)Lead battery manufacturing factory

Effluent

• Effluent is the waste water produced by various industries either during production process or industrial washings.
• The standard pH to be maintained before releasing effluents to the river is $5\text{to}8.5$.
• Increase in pH of river water is harmful for aquatic animals and plants.
• Sulfuric acid is one of the major electrolyte used in lead industries that is highly acidic $(\text{pH}\text{around}2).$
• If the effluents from the lead industry are released to the river water turn more acidic hence pH of river water reach value $3.5–4.5$.

Explanation for incorrect options:

Option (A)

• Soap and detergent factories release effluent in permissible range, pH is between $5.5\text{to}8$.

Option (C)

• Plastic cup manufacturing factories produce alkaline effluent.

Option (D)

• Alcohol distillery releases effluents that have pH between $5.5\text{to}6.5$.

Hence, options (A),(C), and (D) are incorrect.

Hence option (B) is correct. Release of effluent from lead battery manufacturing factory makes water more acidic.