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Online Biochemical Oxygen Demand Monitoring for Wastewater Process Control—Full‐Scale Studies at Los Angeles Glendale Wastewater Plant, California
Author(s) -
Iranpour Reza,
Zermeno Miguel
Publication year - 2008
Publication title -
water environment research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.356
H-Index - 73
eISSN - 1554-7531
pISSN - 1061-4303
DOI - 10.2175/106143007x184672
Subject(s) - wastewater , biochemical oxygen demand , sewage treatment , environmental science , activated sludge , environmental engineering , waste management , chemical oxygen demand , engineering
The main objective of this investigation is to determine whether or not it would be feasible to use the measured values of biochemical oxygen demand (BOD) of wastewater obtained by an online instrument at the Los Angeles/Glendale Water Reclamation Plant (California) for controlling its activated sludge process. This investigation is part of a project to develop online BOD monitoring for process control in the City of Los Angeles wastewater treatment plants. Tests studied the Siepmann und Teutscher GmbH (ISCO‐STIP Inc., Lincoln, Nebraska) BIOX‐1010, which uses a bioreactor containing a culture of microbes from the wastewater to measure soluble BOD in 2 minutes. This rapid approximation to the operation of secondary treatment allows anticipation of system response. Calibration measurements allow the operators to find a conversion factor for the instrument's microprocessor to compute values of BOD that agree well with the standard 5‐day BOD (BOD 5 ) measurement, despite the differences in the details of the two testing methods. This instrument has recently been used at other wastewater treatment plants, at a number of airports in Europe and the United States to monitor runway runoff, and is also being used on waste streams at an increasing number of food processing plants.
A comparison was made between the plant influent BOD values obtained by the BIOX‐1010 online monitor from the end of August, 2000, to late January, 2001, and the individual and average values obtained for the same period using the standard BOD 5 , 20°C test, to determine the effectiveness of the Biox‐1010 to identify shock loads and their duration. Individual BOD estimates and averages over periods of overly high biological loads (shock loads) were compared, and the instrument readings were evaluated for their effectiveness in detecting shock loads. The results were highly satisfactory, so the instrument was used to trigger a shock‐load warning alarm since late September, 2000. This allowed flow diversion and temporary storage to prevent process upsets.