GUIDE 2026 EXAM QUESTIONS AND
VERIFIED ANSWERS
⩥ Second stage of sewage treatment. Answer: Sedimentation - produces
sludge (solids) and effluent (liquid).
⩥ Effluent after sedimentation. Answer: Aerobic biological treatment -
bacteria break down organic matter.
⩥ Sludge from sedimentation. Answer: It is digested anaerobically by
bacteria to produce methane and fertiliser.
⩥ Harmful bacteria in treated water. Answer: Treated water is released
into the environment or further sterilised.
⩥ Anaerobic digestion of sludge. Answer: It produces biogas (methane),
which can be used as energy.
⩥ Aim of chromatography. Answer: To separate components in ink and
identify substances using Rf values.