Biochemical oxygen demand determination

Biochemical Oxygen Demand. The biochemical oxygen demand (BOD) test is an empirical determination of the oxygen requirement of a sample. It is most often appHed to wastewaters, industrial effluents, and poHuted waters. The decrease in the dissolved oxygen concentration resulting primarily from biological action is measured after storage for 5 d at 20°C. 

The size of most biological reactors is determined by pollution load, for example, kg BOD (biochemical oxygen demand) or COD (chemical oxygen demand) per kg MLVSS (mixed liquor volatile suspended solids) per day in the case of suspended growth type systems, and kg BOD or COD per m3 of media or reactor volume in the case of fixed-film type systems. 

A strain of yeast and a strain of bacterium were co-immobilized to fabricate a biochemical oxygen demand (BOD) sensor based on sol-gel derived composite materials97. This novel type of biosensor was developed for water monitoring and was used to determine the BOD values of OECD synthetic wastewater, domestic wastewater, and lake waters. The microorganisms Trichosporon cutaneum and Bacillus subtilis were coimmobilized in the sol-gel composite material, which was composed of silica and the grafting copolymer of poly (vinyl alcohol) and 4-vinylpyridine (PVA-g-P(4-VP)). 

Andre et al. [8] discuss the determination of adenosine-5 -triphosphate by luciferin-luciferase assay. This method was applied to the determination of adenosine-5 -triphosphate in bacterial colonies filtered from samples of polluted water after incubation for different periods. The adenosine-5 -triphosphate was extracted from the residue in the filter and the amount compared with the biochemical oxygen demand of the filtered water. The oxygen uptake rate and the rate of formation of adenosine-5 -triphosphate were then plotted against time, the two curves being similar in up to three to four days incubation, after which adenosine-5 -triphosphate production declined markedly, although oxygen uptake continued to increase. 

Marty and Aim [177] described an automatic determination of the total oxygen demand of waste water. The method gives rapid results and correlates well with chemical oxygen demand and biochemical oxygen demand. Measurements of corrections are made for nitrogen compounds which are the principal interferents. 

Biochemical oxygen demand (BOD) is one of the most widely determined parameters in managing organic pollution. The conventional BOD test includes a 5-day incubation period, so a more expeditious and reproducible method for assessment of this parameter is required. Trichosporon cutaneum, a microorganism formerly used in waste water treatment, has also been employed to construct a BOD biosensor. The dynamic system where the sensor was implemented consisted of a 0.1 M phosphate buffer at pH 7 saturated with dissolved oxygen which was transferred to a flow-cell at a rate of 1 mL/min. When the current reached a steady-state value, a sample was injected into the flow-cell at 0.2 mL/min. The steady-state current was found to be dependent on the BOD of the sample solution. After the sample was flushed from the flow-cell, the current of the microbial sensor gradually returned to its initial level. The response time of microbial sensors depends on the nature of the sample solution concerned. A linear relationship was foimd between the current difference (i.e. that between the initial and final steady-state currents) and the 5-day BOD assay of the standard solution up to 60 mg/L. The minimum measurable BOD was 3 mg/L. The current was reproducible within 6% of the relative error when a BOD of 40 mg/L was used over 10 experiments [128]. 

The effluent from a sewage treatment plant on a river with an upstream biochemical oxygen demand (BOD) of 2 g/m has a discharge of 10 m /s and a BOD of 15 g/m. Determine the best choice of stream reaeration coefficient,... 

One of several oxygen consumption tests (such as biochemical oxygen demand, BOD) to determine biological/chemical contamination level of a water sample. Usually a laboratory chemical test or increasingly measured with equipment, and designed as indicator of inorganically originating contamination such as phosphate. 

DETERMINATION OF BIOCHEMICAL OXYGEN DEMAND (BOD) FROM LABORATORY DATA 16.5... 

Bioanalytical tools for the determination of biochemical oxygen demand... 

The state is assessing the performance of a particular wastewater treatment plant by determining the biochemical oxygen demand (BOD) of its effluent (see Section 2.5). An inspector collects seven replicate samples of the plant effluent and submits them to a water-testing laboratory. The laboratory reports the following results ... 

In the experiments involved the amount of water from the gas scrubber related to the amount of raw input material was about 0.18 m3/t. The pH-value of the water was mildly alkaline, the chloride concentration was about 290 mg Cl /1 and the total amount of phenols about 23 mg/1. Annealing loss of the scrubber water sediment was 2800 mg/1, and the annealing residue amounted to 8000 mg/1. Sulphur was found mainly in an oxidized form. Results of initial experiments using an apparatus for the determination of the biochemical oxygen demand allowed the conclusion that an undisturbed decomposition of the organic components can take place. 

FIGURE 4.5 Diagram of a manometric apparatus for determination of biochemical oxygen demand [52]. (Courtesy of the Hach Company, Ames, lA.)... 

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