Variations in organic waste loading at wastewater treatment plants can create
problems for operators by causing upsets in the treatment process. Operators
respond to these upsets by initiating adjustments to the treatment processes,
such as altering flow, aeration, and food/microorganism ratios (F/M).
Most operators do not have early warning of waste load upsets since traditional
BOD5
analysis takes five days to determine biochemical waste loading changes.Waste load upsets may pass through the plant without effective treatment.
Comparing Waste Loading Tests
The BOD5
analysis by its standard laboratory procedures and dilution method is a costly,
labor intensive test that has a lower detection limit of only 2 mg/L (APHA,
1998), a reproducibility only in the order of +/- 10 to 20% (Constable, 1979)
and an uncertainty of 15 to 20% (Bourgeois W, 2001).Although the BOD test is still a widely accepted parameter for
characterizing water quality, it cannot be used for process control or real-time
monitoring, due to the time it takes to receive test results, at least 5 days
(Constable, 1979).The following
table provides a comparison of BOD5,
COD, and TOC test.The comparison
matrix shows that TOC analysis, as an alternative to BOD5, is a more cost
effective, accurate and timely test, with less interferences, that also has the
capability to be used for process control and real-time monitoring.
The wastewater industry and ITA has recognized the need for a new approach that
provides quantifiable and precise measurements of wastewater loadings and
process control capabilities.
Global regulations allow chemical oxygen demand (COD) or total organic carbon
(TOC) to be substituted for BOD5
when a long-term BOD:COD or BOD:TOC correlation has been demonstrated
(40 CRF 133.104 (b)).
City of Santa Cruz Success
The City of Santa Cruz, California was successful in demonstrating to the
California State Water Resources Control Board
and the
U.S. EPA Region 9
NPDES permit sections a definitive correlation between BOD and TOC at their
wastewater treatment plant. The City of Santa Cruz now reports a monthly average
of TOC and uses the TOC results to report their percent BOD removal efficiency
for compliance purposes (Babatola, 2006).In addition, percent TOC removal efficiencies were calculated using TOC
test results. The
City of Santa Cruz BOD:TOC correlation report
recommended a nationwide study be conducted to develop the percent TOC removal
efficiencies that can be used to replace percent BOD removal efficiencies.
Research Team Looking for 50 Wastewater Treatment Plants (WWTPs)
Dr. Pagilla's research expertise includes developing sustainable technologies
for nutrient control, aerobic and anaerobic membrane bioreactors for wastewater
treatment, and improving bacteria for bioremediation of organic pollutants.
The research team's goal is to collect correlation data for up to 50 WWTP's over
a period of 6 to 12 months starting in 2011. ITA is looking for wastewater
treatment plants who are interested in receiving specific correlation algorithms
for their treatment plant and who routinely measure BOD5,
TOC and/or COD.
All participating treatment plant correlation data will remain confidential and
will be reported anonymously in a final report.All participating treatment plants will receive acknowledgement and a
full copy of the project report.
How Can Your Wastewater Treatment Plant Benefit?
Having reliable and accurate measurements of waste loading can save
wastewater treatment plants thousands of dollars in labor, energy, chemical
costs and provide real-time monitoring and process control capabilities.
These savings are not currently available with the standard practice of
measuring the 5-day biochemical oxygen demand (BOD5).
ITA is looking for wastewater treatment plants who are interested in receiving
specific correlation algorithms for their treatment plant and who routinely
measure BOD5,
TOC and/or COD.
All participating treatment plants will receive acknowledgement and a
full copy of the project final report.
Treatment Plant Benefits of Participation?
Your wastewater treatment plant can benefit by:
Receiving specific BOD5
correlation algorithms for your plant
Increasing plant operations efficiency and response to waste loading upsets.
Reducing energy, chemical and operating costs.
Providing the potential to operate and control your
treatment process automatically using online TOC measurements.
Reducing or eliminating BOD5
measurements which are a labor intensive and time consuming.
Reducing the impact of waste loading discharged to the environment.
Providing a more precise and quantifiable measurement for regulatory
reporting and process control with TOC measurements in the lab or with an
online instrument.
How to Join The Research Team
Joining the TOC research team is easy.Simply fill-in the
project commitment form
to identify your interest and participation level.
Remember, the research team is seeking participation from at least 50 treatment
plants for the correlation study and
invites you to join.
The research team is also looking for organizations to contribute funding.
Contribute Funding
The research team is looking for organizations to contribute funding for this
very important research project.
Help further ITAs mission by supporting and encouraging research and
development. Contribute to help meet the growing need for instrumentation
and automation research.
All funding organizations will receive acknowledgement and a full copy of the
project final report.
References
APHA, A. a. (1998). Standard Methods for the Examination of Water and Wastewater
20th Edition.
Babatola, A. (2006). TOC NPDES Limit Letter. Santa Cruz, California: City of
Santa Cruz.
Bourgeois W, B. J. (2001). On-line monitoring of wastewater quality: a review.
Journal of Chemical Technology and Biotechnology , pp. 337-348.
Boyles, W. (1997). The science of chemical oxygen demand. Hach Lange, Loveland,
Colorado.
Constable. (1979). BOD/TOC Correlations and Their Application to Water Quality
Evaluation. Water, Air and Soil Pollution , 363-375.
Stevens, R. et. al. (2006). TOC analysis correlation with other environmental
parameters. Teledyne Instruments, Mason, Ohio.
USEPA. (2000). Progress in Water Quality, An Evaluation of the National
Investment in Municipal Wastewater Treatment EPA-832-R-00-008, Chapter 2, An
Examination of BOD Loadings Before and After the CWA. Washington, D.C.: US EPA
Office of Water.
About ITA
As part of this research project, ITA will be field-testing online TOC analyzers
to critically assess performance and reliability and to demonstrate monitoring
and control capabilities. ITA has contacted several online TOC manufacturers
that have expressed interest to participate in the field test portion of the
project at volunteer wastewater treatment facilities. The following is a list of
interested online TOC manufacturers:
Paul Lagasse, P.Eng., ITA Board Member and Wastewater Engineer for the City of
Winnipeg, receiving an ITA award, has volunteered to serve on the TOC project
Advisory Panel.
Preliminary List of Participants
The following is an initial list
of treatment facilities and organizations that have expressed interest or joined
in support of the project research team:
