Anaerobic digestion gas handling systems are kept under positive pressure for what reason? - To prevent air from entering the system and mixing with
... [Show More] digester gas, which could cause an explosion
What are the components of an effective safety program? - Regular safety briefings, daily practice, a strong advocate for safety, and a strong central leader.
Which of the following are the most effective sources of information for managers regarding patterns of ergonomic-related injuries and illnesses when evaluating the success of a safety program? - Employee illness records, employee injury records, and worker's compensation claims data
In addition to the mechanical hazards of working around machinery, which of the following environmental hazards are also likely to be faced by maintenance workers at a water resource recovery facility? - Noise, heat insulation (asbestos), and heat illness and stress
What best describes the symptoms of heat stroke? - Confusion, loss of consciousness, and seizures
If the rake on a mechanically cleaned screen is inoperable and there is no visible problem, the issue is likely a(n) ________. - Electrical issue
Resistance temperature detectors (RTDs) are most commonly used on ___________ ambient-range temperatures. - Lower
A level sensor is being used to measure a wet well liquid level and the reading is 4 mA. What is the current level a wet well that is 5 ft wide by 5 ft long by 10 ft deep (1.5 m by 1.5 m by 3 m)? Assume that 1 ft is the lowest liquid level. - 1 ft (0.3 m)
A mesophilic anaerobic digestion system uses a heating hot water system that contains a two heating loop system, referred to as the primary and secondary loops. The secondary hot water loop is designed to typically send hot water to the heat exchangers at a temperature of __________ degrees F. - 150 degrees F (66 degrees C)
When using a gravimetric vibrating trough feeder, one of the routine maintenance requirements is to - Check for caking
What can cause a blockage in a chlorinator atmospheric vent line? - Insects and insect nests
To keep an even flow pattern through a circular clarifier, what should be checked and adjusted on a yearly basis? - Weirs
Which area of the comminutor should be checked if there are "ropes" of rags surrounding the drum of a comminutor? - Cutter head
Dosing polymer at a high rate onto a belt filter press can cause a condition known as ____________ to show up in the belt filter press sludge on the gravity zone. - Belt blinding
Given the following:
Aerobic digester dissolved oxygen level is 3.5 mg/L,
All blowers are running,
pH is 7.2,
Temperature is 19 degrees C,
Specific oxygen uptake rate (SOUR) is 1.2 mg/L O2/g/h,
High surface turbulence, and
The tank is exhibiting high rates of foaming,
What is the first step you should take to reduce the foaming? - Reduce aeration
When using a draft tube mixer on an anaerobic digester, which bearing is most likely to fail? - Shaft
A 1 inch diameter shaft with a runout greater than __________ indicates a bent shaft. - 0.002 inch (0.05 mm)
When cleaning an electric motor with compressed air, what is the maximum recommended pressure you should use? - 50 psi (345 kPa) [Show Less]