wastewater class 1 2

Question 1

physical process controls for making process change by priority

Answer 1

• process air flow
• WAS flow
• RAS flow
• number of tanks in service

Question 2

wastewater rate increases

Answer 2

first step determine rate increase

Question 3

ORP storage solution

Answer 3

Potassium chloride solution or pH 4 or 7 buffer. NOT IN ACIDIC OR BASIC SOLUTION

Question 4

If rotifiers are predominating and you have pin floc what to do?

Answer 4

decrease the mcrt (increase WAS)

Question 5

BOD5 n:p ratio

Answer 5

100:5:1

Question 6

COD n:p ratio

Answer 6

150:5:1

Question 7

What do open loop control systems do

Answer 7

control on variable on basis of another

Question 8

common pneumatic tool contaminants

Answer 8

water, dirt and oil

Question 9

What is most likely use of gfci trip in uv disinfection lamp

Answer 9

connection between lamp and lamp plug is wet

Question 10

what happens when check valve doesnt close properly

Answer 10

wastewater will flow back down rotation pump impellar and shaft backwards

Question 11

what happens when pump and motor are misaligned

Answer 11

cause excessive bearing loading

Question 12

what can wet scrubber gas contain

Answer 12

water soluble toxic or corrosive gases like hydrochloric acid or ammonia

Question 13

three filamentous organisms that cause foaming

Answer 13

nocardia (most common)
microthix parvicella (less common)
type 1863 (rare)

Question 14

if pH is less than 6.5 it is probably the result of what?

Answer 14

Industrial waste

Question 15

if DAF solids loading increases

Answer 15

pressure in air retention tank increases

Question 16

LC50 parameters

Answer 16

Effluent accutely toxic when its 48hr lc50 is 100% or less

effluent not acutely toxic when 48hr lc50 is greater than 100%