GE Power
Water & Process Technologies
Analytical Instruments
6060 Spine Road
Boulder, Colorado 80301 USA
T 800 255 6964 / 303 444 2009
F 303 444 9543
Abstract for Submission to AWWA's 2018 International Symposia on Biological Treatment
Title:Biological Nutrient Removal Optimization using Organics Monitoring
Topics:biological nutrient removal, organics monitoring, process optimization, nitrate removal
EPA and public health concerns about nutrient levels in drinking water and wastewater require water plants to improve treatment methods. Nitrogen-based compounds from run-off, fertilization, sewage, and industry pose year-round problems to utilities trying to meet regulated nitrogen limits. Due to heightened industrial, human, and farming waste, nitrates have been recorded in high concentrations in both surface water and groundwater.
High nitrate levels have been found in California groundwater wells. Therefore, nitrogen removal is becoming an important step in water treatment. One such method, biological denitrification, uses bacteria in an anaerobic setting to feed off a carbon source, and in turn, reduce nitrates. Similar biological treatment has been utilized to remove arsenic, perchlorate, and other contaminants.
Biological denitrification can offer several advantages over alternative methods because it can be operated in a continuous process with zero solids removal required. Treatment processes with minimal waste are becoming more important especially as the push for reuse continues to rise. Biological denitrification can be further optimized by efficient use of the carbon source. The goal is to provide just enough carbon to keep the bacteria alive without leaching excess carbon into the effluent water.
At a particular southern California groundwater well site, a pilot for biological denitrification was optimized with organics monitoring. The result was an unprecedented level of control with carbon feed at less than 10% excess, nitrate effluent less than 1 ppm and carbon effluent less than 4ppm. The value of continuous online organics monitoring is that it can eliminate the guesswork of dosing supplemental carbon and allow for immediate adjustment as opposed to sending samples to third party labs which can take weeks to obtain results. Continuous analysis help utilities not only achieve desired nitrogen removal but also manage their organic disinfection byproduct precursors.
Similar monitoring of organic addition has been applied at wastewater plants needing to understand and control nutrient removal processes. Wastewater plants discharging into protected waterways, like the Chesapeake Bay, are often under intense scrutiny for their discharge. Two wastewater sites are highlighted for using organics monitoring to control carbon dosing to reach desired nutrient removal levels. With the demand for affordable drinking water, the stress of water resources, and the heightened awareness of pollution, it is beneficial to optimize water plants for efficient removal of nutrient and organic contaminants.
Authors
Amanda Scott
Municipal Product Manager, GE Analytical Instruments
M.Phil Chemical Engineering, University of Cambridge
B.E. Chemical Engineering, Vanderbilt University
For more information on this submission, please contact Amanda Scott, GE Analytical Instruments, r 720-390-9714.