Energy, total carbon, and oxygen demand

Abstract

The biodegradable content of organics in aqueous solution can be assessed in two ways: by measuring the change in organic content effected by bacterial metabolism; or by measuring the consumption of oxygen by bacteria in effecting the removal of organics. In addition to oxygen, two possible parameters for pollution measurement are thermodynamic energy change and total carbon change. The validity of applying thermodynamic concepts to biological systems is questioned. Total carbon changes during the process of biological oxidation are considered to offer an excellent potential as a measure of biodegradable organic content. The use of carbon as a parameter in the context of the two analytical procedures derived at Rice University affords a flexibility in selection of technique based on the required precision of results. (Key words: Pollution measurement; oxygen demand; bacterial synthesis.)

Energy Yields and Growth of Heterotrophs

“…Whereas other workers (23,24,55,118) have reported incorporation of approximately 60 percent of the ca.rbon of substra.tes such as glucose and glycerol at the expense of the oxidized 40 percent, bacterium HR oxidized to CO2 approximately 75 per cent of the methane and alcohol carbon provided and incorporated only 2S percent. A greater demand for oxygen would logically be expected when a hydrocarbon is the sole carbon source since many of the carbohydrates, amino acids, and other cellular components are oxygenated compounds.…”

“…Additionally impressive evidence of the closeness of fit to approximately 0.6 of the ratio of substrate carbon assimilated to total utilized is found in studies of the aerobic growth of mixed cultures of soil and sewage bacteria at the expense of known quantities of "pure biochemicals" (24,119,120 Busch (23) observed that maximal microbial growth ("solids produc tion") occurred in sewage supplemented with glucose when (i) all of the sugar was utilized, and (ii) enough oxygen was consumed to indicate that 41 percent of the total had been oxidized. So dependable was this latter figure in a number of repetitions that it was then proposed (24,47) that cal culations based on this value (which can be easily and Quickly determined) might well be employed as the standard for estimation of BOD 2 in preference to waiting five days for an answer, as the most widely used method now necessitates.…”

Methods involved in the treatment of four representative pharmaceuticals in hospital wastewater using sonochemical and biological processes

“…Before the application of the aerobic biological method (BS) to HWW, a control test for the experimental system is performed, using glucose (at 40 mg TOC L −1 , glucose is a reference substance for biodegradation [25 , 26] ) and measuring oxygen consumption. Once the proper performance of microorganisms is established, the BS is applied to the HWW sample for 36 h, also monitoring the oxygen consumption.…”