Unit 4: Wastewater Treatment Flashcards
Which of the following is NOT accomplished by wastewater treatment:
A: Removal of organic material
B: Replenishment of plant nutrients for receiving stream
C: Destruction or inactivation of pathologic organisms
D: Removal of harmful chemicals
B: Replenishment of plant nutrients for receiving stream
Which of the following is NOT accomplished by wastewater treatment:
A: Removal of organic material
B: Replenishment of plant nutrients for receiving stream
C: Destruction or inactivation of pathologic organisms
D: Removal of harmful chemicals
B: Replenishment of plant nutrients for receiving stream
True or False:
An animal rendering plant has more pathogenic organisms in its wastewater than a hospital
False
A hospital has more pathogenic organisms in its wastewater
What is the characteristic colour and smell of a anaerobic wastewater
Black and foul smelling
In raw wastewater, what percentage of dissolve solids is composed of colloidal solids?
0%
Colloidal solids are not filterable
How does the release of nitrate and phosphate contribute to the death of fish and other organisms in the receiving stream?
Stimulates the growth of algae and plants
What type or types of bacteria can break down organic content in oxygen-deficient wastewater
Both anaerobic bacteria and facultative bacteria
For an isolated community of 500 people, what is the most efficient method of wastewater treatment
Sewage Lagoons (wastewater stabilization pond)
What is the goal of wastewater prevention-treatment?
A: Removal of organic material
B: Removal of inorganic grit and floatables
C: removal of taste and odours
D:Production of high quality sludge
B: Removal of inorganic grit and floatables
What stage of wastewater treatment, prior to aeration and biological treatment, involves the removal of settleable solids out of solution
Primary Treatment
The tertiary process of wastewater treatment does what
Disinfection and and removal of inactive pathogenic microorganisms
What happens to sludge that is collected from primary clarifiers
Pumped to anaerobic digestion tanks
What is anaerobic treatment?
An energy-efficient process that reliably removes biochemical oxygen demand (BOD), chemical oxygen demand (COD), and total suspended solids (TSS) from wastewater.
What happens to activated sludge during secondary treatment?
It is cycled through the stage to increase microbial content
The majority of ANAEROBIC activity generally occurs at which depth in a wastewater stabilization pond?
A - Surface of the pond
B - at medium depth
C - at the bottom of the pond
D - Throughout the pond
C - At the bottom of the pond
The typical wastewater pond flow rate is designed for (how many) litres of wastewater per person per day
500 litres
What is the beneficial effect of wind action on a facultive pond?
Increases dissolved oxygen content
A wastewater pond has a measured depth of 3.5 meters. It is likely a _______ type of pond.
Anaerobic pond
What’s the problem with algae removal from a wastewater stabilization pond?
The pH may get too low, upsetting the normal biological activity of the pond
What is the purpose of a wastewater storage pond
Continued breakdown of organic material and reduction of pathogenic organisms
Thermal turnover in spring and autumn creates this natural phenomenon in a wastewater stabilization pond
Denser water sinks, disturbing the organic matter at depth
What is a primary advantage of a wetland facility in wastewater treatment
Avoidance of bioaccumulation of toxins in wildlife near site
If there is a significant accumulation problem at a wastewater treatment facility, what is the most effective remedy?
Mechanical aeration
What’s the main problem with scum accumulation in a wastewater pond
Reduction in sunlight penetration and lower dissolved oxygen
Where is the location of vegetation beneficial to a wastewater stabilization pond
At the lagoon berms
What is rip rap
Large rocks used to prevent erosion on inner berm slopes
