SEWAGE TREATMENT EXAM SCRIPT 2025 QUESTIONS
WITH ANSWERS RATED A+
✔✔8.1 hypoxic waterways - ✔✔bodies of water that are low in dissolved oxygen
✔✔8.1 persistent organic pollutants (POPs) - ✔✔compound with carbon in it that resists
photochemical, biological and chemical degradation
✔✔8.1 Biomagnification - ✔✔The increase in chemical concentration in animal tissues
as the chemical moves up the food chain
✔✔8.1 Bioaccumulation - ✔✔The accumulation of a substance, such as a toxic
chemical, in various tissues of a living organism.
✔✔8.1 oxygen sag curve - ✔✔The curve obtained when the concentration of dissolved
oxygen in a river into which sewage or some other pollutant has been discharged is
plotted against the distance downstream from the sewage outlet.
✔✔8.2 effluent - ✔✔liquid waste or sewage discharged into a river or the sea.
✔✔8.2 Composting - ✔✔The process of helping biodegradable wastes to decompose
naturally
✔✔8.2 Landfill mitigation - ✔✔Measures or actions to reduce the impact in the
environment by the generation of waste through its reuse, reuse, treatment or final
disposal thereof.
✔✔8.2 E-waste - ✔✔Discarded electronic equipment such as computers, cell phones,
television sets, etc.
✔✔8.2 Integrated waste management - ✔✔Variety of strategies for both waste
reduction and waste management designed to deal with the solid wastes we produce.
✔✔8.2 Primary treatment (sewage) - ✔✔Mechanical sewage treatment in which large
solids are filtered out by screens and suspended solids settle out as sludge in a
sedimentation tank.
✔✔8.2 Secondary treatment (sewage) - ✔✔A biological oxidation process in which the
levels of suspended and dissolved organic materials are reduced, i.e. the sewage is
decomposed by means of bacteria which use the nutrients from the sewage together
with oxygen from the air to break down the sewage
WITH ANSWERS RATED A+
✔✔8.1 hypoxic waterways - ✔✔bodies of water that are low in dissolved oxygen
✔✔8.1 persistent organic pollutants (POPs) - ✔✔compound with carbon in it that resists
photochemical, biological and chemical degradation
✔✔8.1 Biomagnification - ✔✔The increase in chemical concentration in animal tissues
as the chemical moves up the food chain
✔✔8.1 Bioaccumulation - ✔✔The accumulation of a substance, such as a toxic
chemical, in various tissues of a living organism.
✔✔8.1 oxygen sag curve - ✔✔The curve obtained when the concentration of dissolved
oxygen in a river into which sewage or some other pollutant has been discharged is
plotted against the distance downstream from the sewage outlet.
✔✔8.2 effluent - ✔✔liquid waste or sewage discharged into a river or the sea.
✔✔8.2 Composting - ✔✔The process of helping biodegradable wastes to decompose
naturally
✔✔8.2 Landfill mitigation - ✔✔Measures or actions to reduce the impact in the
environment by the generation of waste through its reuse, reuse, treatment or final
disposal thereof.
✔✔8.2 E-waste - ✔✔Discarded electronic equipment such as computers, cell phones,
television sets, etc.
✔✔8.2 Integrated waste management - ✔✔Variety of strategies for both waste
reduction and waste management designed to deal with the solid wastes we produce.
✔✔8.2 Primary treatment (sewage) - ✔✔Mechanical sewage treatment in which large
solids are filtered out by screens and suspended solids settle out as sludge in a
sedimentation tank.
✔✔8.2 Secondary treatment (sewage) - ✔✔A biological oxidation process in which the
levels of suspended and dissolved organic materials are reduced, i.e. the sewage is
decomposed by means of bacteria which use the nutrients from the sewage together
with oxygen from the air to break down the sewage
