Advances in Online Optical Monitoring of BOD/cBOD in Wastewater

Oral Presentation

Prepared by C. Russo, N. Klinkhammer, G. Klinkhammer
ZAPS Technologies Inc., 4314 SW Research Way, Corvallis, OR, 97333, United States


Contact Information: chris.russo@zapstechnologies.com; 541-207-1122


ABSTRACT

Biochemical oxygen demand (BOD) has been the standard measure for predicting the net effect of anthropogenic waste on the oxygen content of natural waters since the 19th century. Conventional BOD analysis measures oxygen consumption using seed microorganisms in a bioreactor, typically over a 5-day period (BOD5). Here we discuss an alternate methodology: Hybrid Multispectral Analysis (HMA).

Hybrid Multispectral Analysis (HMA) is a purely optical approach to online monitoring which uses a combination of in-situ fluorescence, absorption and scattering measurements in a single flow-cell to continuously characterize chemical bonding and molecular structure. In the HMA approach, high intensity light is used to identify molecular bonds and particles in the sample stream enabling the quantification of the oxidants and oxidizers present that ultimately drive oxygen demand. The HMA method’s use of light allows for a very rapid and precise characterization of the sample stream without the need of surrogate microbial seeds, reagents or other sample disruptions. The end result is a more continuous, direct and efficient form of monitoring.

Following a brief introduction to the method we will continue by presenting BOD data generated using the HMA approach compared to those data acquired using traditional BOD5 techniques (e.g. SM 5210B). This comparison will be followed with a discussion of such topics as data management, maintaining data integrity and nuances when comparing more precise optically generated data to inherently more noisy traditional techniques Finally, we show several examples of how continuous online data, when placed before an experienced plant operator, can result in increased plant efficiency and improved plant management.