WASTEWATER

By Rick Lallish

What is the process of bacteria integrating more phosphorus than needed for growth?

A. Photosynthesis

B. Luxury uptake

C. Nitrification

D. Dephospication

Answer: B. Luxury uptake is the process of removing phosphorus from the system by using phosphorus-accumulating organisms. PAOs are facultative heterotrophic bacteria. When cycled from anaerobic to aerobic or anoxic conditions, the bacteria will gather and store excess phosphorus. PAOs may store up to 40% of their dry weight as phosphorus. This is one method of decreasing the phosphorus content biologically from the treatment process. More information may be found in WEF textbook, Wastewater Treatment Fundamentals 1: Liquid Treatment, Chapter 5.

DRINKING WATER

By Drew Hoelscher

How long does a community water system have to comply with the PFAS National Primary Drinking Water Regulation?

A. Must do so immediately

B. 1 year

C. 3 years

D. 5 years

Answer: D. On April 10, 2024, the U.S. EPA finalized the regulation and set maximum contaminant limits for five PFAS and a hazard index for PFAS mixtures. The regulation gave community water systems five years to comply due to potential significant investments for treatment plant upgrades. Additional information about the PFAS National Primary Drinking Water Regulation is at epa.gov/sdwa/and-polyfluoroalkyl-substances-pfas

About the author(s)

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.