Objective Question & Answer

P. Proportional weir - 3. Grit chambers

Reason: A proportional weir (also known as a Sutro weir) is provided at the outlet of a rectangular grit chamber to maintain a constant horizontal flow velocity (0.3m/s) regardless of discharge variations.

Q. Muffle furnace - 4. Volatile solids

R. Schmutzdecke - 2. Slow sand filters

Reason: A Schmutzdecke (or dirty layer) is a gelatinous biological film composed of algae, bacteria, and protozoa that forms on the top surface of a slow sand filter, acting as the primary layer for water purification.

S. Methaemoglobinemia - 1. Nitrate

Reason: Methaemoglobinemia (commonly known as Blue Baby Disease) is caused by high concentrations of nitrates (>45mg/l) in drinking water, which impairs oxygen transport in infants' blood.