WASTEWATER
By Rick Lallish
In a biological nutrient removal process, what is the condition where bacteria incorporate more phosphorus than needed for growth?
A. Denitrification
B. Endogenous respiration
C. Luxury uptake
D. Precipitation
Answer: C. Luxury uptake is the process by which bacteria cycle between anoxic or aerobic and anaerobic conditions. In that process, the bacteria tend to pick and store excess phosphorus in the anoxic or aerobic environment. With this mode, phosphorus may be removed from the treatment process when the biomass is removed from the system. The nutrient removal process has become more important to wastewater treatment in recent years, and operators should be aware of the different modes of treatment related to phosphorus and nitrogen removal.
DRINKING WATER
By Drew Hoelscher
What is the most important step an operator should take before performing maintenance on a motor or pump?
A. Notify co-workers so they do not operate the equipment
B. Notify the manufacturer
C. Review and perform the lockout/tagout procedure
D. Schedule the maintenance during low demand hours
Answer: C. Maintenance is typically performed on a corrective, preventive, risk or condition-based philosophy and is not always performed with advance notice. However, it is critical to follow proper lockout and tagout procedures to ensure you and your co-workers can safely perform the required tasks.
About the authors
Rick Lallish is water pollution control program director, and Drew Hoelscher is program director of drinking water operations at the Environmental Resources Training Center of Southern Illinois University Edwardsville.
