Background Orbitally shaken flasks are commonly used at an early stage of bioprocess development with mammalian cells. In contrast to large-scale stirred-tank bioreactors, shaken flasks are usually operated in probe-independent bioprocesses, i.e. without strictly controlling the pH or dissolved oxygen concentration (DO). As a consequence, gas transfer issues are thought to limit the effectivene...

a lab-scale sbr equipped with a flat sheet membrane in submerged configuration that is named msbr was used for the treatment of composting leachate. it was fed by biologically treated leachate with overall 70-1360 mg/l chemical oxygen demand (cod). the values of ph, electrical conductivity (ec), and dissolved oxygen (do) were monitored routinely. however, analysis of total cod, soluble cod (sco...

Polyaniline (PANI) has been shown to possess excellent catalytic activity toward oxygen reduction, however, this molecule may interfere with the electrochemical measurement of other targets when using a polyaniline modified platinum (PANI/Pt) electrode. In this study, we have demonstrated the considerable effects of dissolved oxygen on the sensing of hydrogen peroxide with the PANI/Pt electrode...

Type II methanotrophs produce polyhydroxybutyrate (PHB), while Type I methanotrophs do not. A laboratory-scale fluidized bed reactor was initially inoculated with a Type II Methylocystis-like dominated culture. At elevated levels of dissolved oxygen (DO, 9 mg/L), pH of 6.2-6.5 with nitrate as the N-source, a Methylobacter-like Type I methanotroph became dominant within the biofilms which did no...

Dissolved oxygen concentrations in the lower reaches of the Tualatin River in northwest Oregon are the result of many processes. Temperature imposes a seasonal signal through the solubility of oxygen in water. Streamflow determines the travel time through the system and affects the amount of oxygen consumed via processes such as ammonia nitrification and the decomposition of organic material in...

We investigated the influence of oxygen demand (developmental stage) and supply (hypoxia, water flow rate, the chorion and body movements) on the oxygen concentration within the boundary layer next to the chorion of embryos or skin of larvae of rainbow trout (Oncorhynchus mykiss). Oxygen microelectrodes were used to measure dissolved oxygen (DO) within the boundary layer of trout embryos and la...

Industrial filamentous fungal fermentations are typically operated in fed-batch mode. Oxygen control represents an important operational challenge due to the varying biomass concentration. In this study, oxygen control is implemented by manipulating the substrate feed rate, i.e. the rate of oxygen consumption. It turns out that the setpoint for dissolved oxygen represents a trade-off since a lo...

Simultaneous nitrification and denitrification (SND) under low dissolved oxygen (DO) and anaerobic/aerobic(anoxic) enhanced phosphorus removal (EBPR) are two processes that can significantly reduce the energy and carbon required for nutrient removal. The combination of the two processes is expected to achieve biological nutrient removal with minimal requirement of oxygen and carbon. In this stu...

A polypropylene hollow fiber membrane module is used for separating dissolved gases which contain dissolved oxygen from water. These dissolved gases can be used for underwater breathing. To be used for a human, the minimum amount of oxygen is essential. To increase separation of dissolved gases, much water and high surface area of hollow fibers are requested. For efficient separation system, pe...