Standard Biochemical Oxygen Demand Research Articles

Real Time BOD Monitoring for Wastewater Process Control

This is a preliminary investigation of a method for the timely monitoring of wastewater biochemical oxygen demand (BOD). Many ecological and economic pressures support the use of BOD measurement methods fast enough to prevent process upsets. Since the standard laboratory procedure takes five days, and previously used fast tests are unsatisfactory for various reasons, tests were made on the Nissin Electric BOD-2000 instrument, which uses a yeast-based biosensor to measure soluble BOD in 30 min. It has been used successfully in the pharmaceutical and food industries. An initial attempt was made to place the instrument in field service. This attempt was unsuccessful, so the present study concentrated on comparing its operation in the laboratory with the results of the standard five-day BOD test (BOD\d5) procedure. The two types of tests were compared for samples from Terminal Island Treatment Plant (TITP), Bureau of Sanitation of the city of Los Angeles, using various combinations of filter porosities and wastewater sources in an attempt to establish a measurement routine that would not suffer from clogging problems that plagued the field test. Under these conditions the results from the instrument are excellent, and we briefly discuss further work needed to bring it into field use. This test is believed to be the first effort to assess the capability of this technology in a wastewater application in the United States.

Microbial membrane-modified dissolved oxygen probe for rapid biochemical oxygen demand measurement

This paper describes the preparation and response of a Bacillus subtilis-Bacillus licheniformis 7B microbial membrane-modified dissolved oxygen probe in standard biochemical oxygen demand ( BOD) check solutions containing glucose and glutamic acid at different temperatures, pH values and in the presence of some dissolved inorganic salts. The modified probe shows stable and reproducible sensing characteristics. The readings obtained for some wastewater samples from a local sewage-treatment plant compare favourably with the BOD 5 values obtained from a conventional BOD measurement technique.

Structural features associated with degradable and persistent chemicals

AbstractA multivariate statistical method and a heuristic method were employed to examine the structural features associated with the persistence or degradation of 287 chemicals tested with the standard biochemical oxygen demand (BOD) procedure. The data base consisted of 196 “degradable” chemicals with a half‐life of less than 15 d (e.g., Theoretical BODs (ThOD) > 16%) and 91 “persistent” chemicals with a half‐life of more than 15 d. The multivariate statistical analysis consisted of (1) calculating 54 molecular connectivity indices, five physicochemical properties and eight principal components from the molecular connectivity indices, (2) clustering the chemicals on the basis of the principal components and one of the physicochemical properties, Kow and (3) discriminating between persistent and degradable chemicals using the molecular connectivity indices and the physicochemical properties as discriminating variables within each cluster. The heuristic approach used the results of the multivariate analyses and the literature on biodegradation to identify a series of structural features associated with degradable and persistent chemicals.The best iteration of the multivariate technique correctly predicted 85% of the degradable chemicals and 94% of the persistent chemicals. In contrast, the heuristic approach correctly predicted 91% of the degradable chemicals and 96% of the persistent chemicals. Twelve structural features or chemical classes were associated with degradable chemicals and 16 structural features were associated with persistent chemicals. The analysis is presented as a potential technique for rapidly assessing the relative degradability of discrete organic chemicals. The structural features identified are offered as tentative hypotheses to be examined with a larger and more diverse data set.

OXYGEN DEMAND OF LAKES: SEDIMENT AND WATER COLUMN BOD

ABSTRACT The total biochemical oxygen demand (TBOD, g O2m−2) of two small, ≤ 5.0 ha, eutrophic lakes in central Iowa was estimated from measurements of the biochemical oxygen demand (BOD) from the top 25 mm of sediments (SBOD) and summation of the BOD values from each 1-meter strata of the water column (WBOD). Standard BOD procedures were used for both sediment and water column biochemical oxygen demand, although a special protocol was developed for the sediments. Continuous recording of the oxygen consumption of selected sediment samples during the five-day BOD procedure revealed a high initial oxygen demand which then declined exponentially over the five-day interval; the oxygen consumption in 20 minutes averaged 26 percent of the mean five-day SBOD value. The sediment and water column biochemical oxygen demand were measured for 28 months in both lakes. WBOD (9 O2m−2) values ranged from 2.0 to 13.1 and mean values were 5.1 and 6.5, respectively, in the two lakes. SBOD (g O2m−2) values ranged from 27.7 to 138.6 and averaged 79.6 and 80.3 in the two lakes. Monthly variation in water column and sediment biochemical oxygen demands were independent. Sediment values were greater than 90 percent (96.5 percent of the total demand in one lake and 94.0 percent in the other lake) of the total biochemical oxygen demand in 9 of 56 monthly samples in both lakes. During the winter ice-covered interval, sediment biochemical oxygen demand and the dissolved oxygen content of the water column were negatively correlated for the two 1-m strata nearest to the bottom.

Design guidelines for incompletely mixed or aerobic–anaerobic aerated lagoons

Investigations with three laboratory-model aerated lagoons proved that incompletely mixed (or aerobic–anaerobic) aerated lagoons can be rationally designed by using the Wehner–Wilhelm equation or Thirumurthi chart, which graphically depicts that equation for applications in biological wastewater treatment. Whereas the biological factors (such as temperature and wastewater quality) are delineated by a first-order biochemical oxygen demand (BOD) removal coefficient (K), the physical–hydraulic regimes (such as mixing pattern and depth–width ratio of lagoon) are represented by a dispersion index. The key to the design is the standard BOD removal coefficient (Ks), which is evaluated to be 0.29/day for municipal wastewater at a standard temperature (T) of 20 °C and organic load (L) of 20 g∙m−3∙day−1. When the actual T and L of a lagoon, however, are other than the standard values, appropriate corrections should be assigned to Ks to obtain K. Two equations for such corrections are provided.Two companion papers of previous studies demonstrated the successful application of the same method for designing waste stabilization ponds and completely mixed (aerobic) aerated lagoons; the present study accomplishes the same for incompletely mixed lagoons. An example design is included; the technique, however, needs to be verified by investigating the actual, field lagoons.

The electrolytic respirometer—I factors affecting oxygen uptake measurements

The electrolytic respirometer provides a more accurate and more complete measurement of biochemical oxygen demand (BOD) of wastewaters samples than normally is obtained by the standard dilution BOD method. Laboratory and field studies have shown that the electrolytic respirometer is a dependable instrument for making BOD measurements, is simple to operate, and provides a continuous readout of the oxygen uptake reaction. The major factors affecting oxygen uptake measurements with the electrolytic respirometer are the mixing rate and the concentration of oxygen demanding material in the sample. These system limitations can be overcome by using simple procedures such as increased mixing rate or enrichment of the oxygen in the air in contact with the sample. The precision of BOD measurement with the electrolytic respirometer was considerably greater than with the dilution method.

Waste-Induced Oxygen Uptake of An Alaskan Estuary

In Knik Arm, Alaska, oxygen consumption in 2○ waters inoculated with settled domestic sewage was measured over a twenty-day period. Oxygen uptake in the natural waters alone was substantial at this low temperature, and addition of sewage considerably increased the demand for oxygen. It was demonstrated that the oxygen consumption observed could not be directly related to an increase in bacterial numbers but rather to the effect (on bacterial growth) of planktonic organisms in the natural waters. High concentrations of glacial till had no effect on oxygen consumption. The standard Biochemical Oxygen Demand test was shown to be a poor parameter for assaying wastes to be disposed to waters whose in situ conditions vary widely from those of the standard procedure.