Water quality is being impaired all over the world due to excessive nutrients from agricultural runoff and wastewater. Nitrogen and phosphorus cause algae blooms, which in turn deplete oxygen in the water and make the water environment inhospitable for aquatic life. The Gulf of Mexico suffers from a “dead zone" due to low oxygen, also known as hypoxia, at the mouth of the Mississippi River.
Nationwide, regulations are starting to strengthen with regards to nutrient limits; as a result, water utilities are facing billions in costs to meet increasing demands to enhance treatment processes, improve infrastructure and address sewer overflows. The estimated cost for all Illinois plants to implement phosphorus removal ranges between $570 million to almost $3 billion.
One method currently being studied by the Metropolitan Water Reclamation District of Greater Chicago (MWRD) to target nutrient removal is called the “Molecular Gene Probe” method. Dr. Geeta Rijal, MWRD supervising environmental microbiologist, is leading the research in an effort to understand the dynamics of ammonia oxidizing bacteria and nitrite oxidizing bacteria, which play an important role in the removal of nitrogen from the wastewater treatment process.
Rijal, who has worked for the MWRD for 12 years, presented her research at the American Society of Microbiology’s 113th general meeting in Denver, Colo., in late May.
“There are nutrient-removing bacteria naturally growing in our wastewater system,” Rijal said. “With a proper molecular identification method, we can help to evaluate their abundance and nutrient removal potential.”
