Unit 4: Wastewater Treatment

Question 1

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

Answer 1

B: Replenishment of plant nutrients for receiving stream

Question 2

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

Answer 2

B: Replenishment of plant nutrients for receiving stream

Question 3

True or False:
An animal rendering plant has more pathogenic organisms in its wastewater than a hospital

Answer 3

False
A hospital has more pathogenic organisms in its wastewater

Question 4

What is the characteristic colour and smell of a anaerobic wastewater

Answer 4

Black and foul smelling

Question 5

In raw wastewater, what percentage of dissolve solids is composed of colloidal solids?

Answer 5

0%

Colloidal solids are not filterable

Question 6

How does the release of nitrate and phosphate contribute to the death of fish and other organisms in the receiving stream?

Answer 6

Stimulates the growth of algae and plants

Question 7

What type or types of bacteria can break down organic content in oxygen-deficient wastewater

Answer 7

Both anaerobic bacteria and facultative bacteria

Question 8

For an isolated community of 500 people, what is the most efficient method of wastewater treatment

Answer 8

Sewage Lagoons (wastewater stabilization pond)

Question 9

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

Answer 9

B: Removal of inorganic grit and floatables

Question 10

What stage of wastewater treatment, prior to aeration and biological treatment, involves the removal of settleable solids out of solution

Answer 10

Primary Treatment

Question 11

The tertiary process of wastewater treatment does what

Answer 11

Disinfection and and removal of inactive pathogenic microorganisms

Question 12

What happens to sludge that is collected from primary clarifiers

Answer 12

Pumped to anaerobic digestion tanks

Question 13

What is anaerobic treatment?

Answer 13

An energy-efficient process that reliably removes biochemical oxygen demand (BOD), chemical oxygen demand (COD), and total suspended solids (TSS) from wastewater.

Question 14

What happens to activated sludge during secondary treatment?

Answer 14

It is cycled through the stage to increase microbial content

Question 15

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

Answer 15

C - At the bottom of the pond

Question 16

The typical wastewater pond flow rate is designed for (how many) litres of wastewater per person per day

Answer 16

500 litres

Question 17

What is the beneficial effect of wind action on a facultive pond?

Answer 17

Increases dissolved oxygen content

Question 18

A wastewater pond has a measured depth of 3.5 meters. It is likely a _______ type of pond.

Answer 18

Anaerobic pond

Question 19

What’s the problem with algae removal from a wastewater stabilization pond?

Answer 19

The pH may get too low, upsetting the normal biological activity of the pond

Question 20

What is the purpose of a wastewater storage pond

Answer 20

Continued breakdown of organic material and reduction of pathogenic organisms

Question 21

Thermal turnover in spring and autumn creates this natural phenomenon in a wastewater stabilization pond

Answer 21

Denser water sinks, disturbing the organic matter at depth

Question 22

What is a primary advantage of a wetland facility in wastewater treatment

Answer 22

Avoidance of bioaccumulation of toxins in wildlife near site

Question 23

If there is a significant accumulation problem at a wastewater treatment facility, what is the most effective remedy?

Answer 23

Mechanical aeration

Question 24

What’s the main problem with scum accumulation in a wastewater pond

Answer 24

Reduction in sunlight penetration and lower dissolved oxygen

Question 25

Where is the location of vegetation beneficial to a wastewater stabilization pond

Answer 25

At the lagoon berms

Question 26

What is rip rap

Answer 26

Large rocks used to prevent erosion on inner berm slopes