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The biological oxygen demand (BOD) test is widely used in many wastewater treatment plants. The conventional BOD tests are usually time-consuming and the results are often out of date for process control purposes. The aim of this research was to compare the manometric respirometric test with common chemical methods in the determination of BOD of wastewater from a pulp and paper mills as well as to evaluate the BOD 7 values of both wastewaters from the short-term respirometric measurements. The results showed that there were differences in the BOD7 values of paper mill samples measured by conventional and respirometric methods. The main cause was found to be the dilution solution used in the conventional BOD tests. Using the same mineral solution in the respirometric measurements diminished the difference remarkably. Evaluation of the BOD7 value after two or three days incubation was proved to work very well and the estimated results were close to measured values (deviations 1%–12%).

The biodegradability of certain biofuels was studied in the case of forest soils using the manometric respirometric technique, which was proved to be very suitable for untreated, fertilized as well as pH adjusted soils. Experiments carried out in infertile sandy forest soil gave a BOD/ThOD value of 45.1% for a typical model substance, that is, sodium benzoate after a period of 30 days and mineral addition improved the BOD/ThOD value to a value of 76.2%. Rapeseed oil-based chain oil almost did not biodegrade at all in 30 days in nonprocessed soil, and when pH was adjusted to 8.0, the BOD/ThOD value increased slightly to a value of 7.4%. Mineral addition improved the BOD/ThOD value on average to 43.2% after 30 days. The combined mineral addition and pH adjustment together increased the BOD/ThOD value to 75.8% in 30 days. The observations were similar with a rapeseed oil-based lubricating oil: after 30 days, the BOD/ThOD value increased from 5.9% to an average value of 51.9%, when the pH and mineral concentrations of the soil were optimized. The mineral addition and pH adjustment also improved the precision of the measurements significantly.

The aim of this research was to study the suitability of a manometric respirometric test (OECD 301F) for the determination of biological oxygen demand (BOD) in domestic wastewater. This was done by comparing four different BOD tests (a manometric respirometric test, oxygen sensor determination, iodometric titration, and UV absorption measurement) and by evaluating the BOD7 value after a short-term measurement applying the manometric respirometric test. Measurements were done in three different laboratories. The respirometric test was performed well on municipal sewage, and the precision of results was good. There were minor deviations between BOD7 values as determined by the different methods, but the deviations were not essentially big enough to have a practical impact. Evaluation of the BOD7 value after two or three days' incubation by the respirometric method was shown to work well; average deviations between measured and evaluated values after three days' incubation were 5–18%. Hence, the manometric respirometric test proved to be a rapid and suitable tool for process control purposes.