Wastewater Flashcards
(37 cards)
What is the purpose of a wastewater collection system?
To convey wastewater from its source to a treatment facility.
What is a lift station?
A pumping station used to move wastewater from lower to higher elevation.
What are common sewer system types?
Sanitary, storm, and combined sewers.
What is infiltration in sewer systems?
Groundwater entering the sewer through cracks and joints.
What is inflow in sewer systems?
Surface water entering the sewer from illegal connections or manholes.
What is smoke testing used for?
To detect sources of inflow in a sewer system.
Why is sewer maintenance important?
To prevent blockages, overflows, and structural failure.
How is odor controlled in sewer systems?
Using chemical dosing, ventilation, and biofilters.
What are the main stages of wastewater treatment?
Preliminary, primary, secondary, and tertiary (advanced) treatment.
What is the goal of wastewater treatment?
To remove contaminants and protect public health and the environment.
What does preliminary treatment remove?
Large solids, grit, and grease.
What equipment is used in preliminary treatment?
Bar screens, grit chambers, and comminutors.
What is the purpose of a grit chamber?
To remove sand, gravel, and other heavy particles.
What is the role of grease traps?
To capture fats, oils, and grease from wastewater.
What is primary treatment?
The physical process of settling suspended solids from wastewater.
What is the typical efficiency of BOD removal in primary treatment?
20% to 30%.
What is a primary clarifier?
A tank that allows solids to settle and scum to float for removal.
What is secondary treatment?
Biological processes used to remove dissolved and suspended organic matter.
What is the activated sludge process?
A biological treatment where microbes break down organic material in aeration tanks.
What is a trickling filter?
A biological filter where wastewater is sprayed over media colonized by microorganisms.
What is the typical BOD removal efficiency in secondary treatment?
85% to 95%.
What nutrients are commonly removed in wastewater treatment?
Nitrogen and phosphorus.
What is nitrification?
The biological oxidation of ammonia to nitrate.
What is denitrification?
The conversion of nitrate to nitrogen gas under anoxic conditions.
