The effect of dissolved oxygen concentrations on the behavior of Serratia marcescens and on yields of asparaginase and prodigiosin produced in shaken cultures and in a 55-liter stainless-steel fermentor was studied. A range of oxygen transfer rates was obtained in 500-ml Erlenmeyer flasks by using internal, stainless-steel baffles and by varying the volume of medium per flask, and in the fermen...

In cellular, tissue-level or whole organ bioreactors, the level of dissolved oxygen is one of the most important factors requiring control. Hypoxic environments may lead to cellular apoptosis, while hyperoxic environments may lead to cellular damage or dedifferentiation, both resulting in loss of overall tissue function. This manuscript describes the creation, characterization and validation of...

Orbal multi-channel oxidation ditches have received relatively little attention and thus knowledge of their characteristics is not as highly advanced as for other oxidation ditch systems. Dye tracer and dissolved oxygen measurements have been undertaken to elucidate the mixing characteristics of a three-channel Orbal system treating 80 Ml/d. The dissolved oxygen concentrations showed a complex ...

Textile manufacturing consumes a considerable amount of water in its manufacturing processes. The water is primarily utilized in the dyeing and finishing operations of the textile establishments. Considering both the volume generated and the effluent composition, the textile industry wastewater is rated as the most polluting among all industrial sectors. In this study a combined anaerobic-aerob...

The concentrations of toxic effluents released into freshwater aquatic environments are increasing day by day and affect the aquatic biota. The present study outlined the evaluation of physicochemical parameters such as water temperature, pH, dissolved oxygen (DO), biological oxygen demand (BOD), chemical oxygen demand (COD), phosphates (PO42--P), nitrates (NO3--N), electrical conductivity (EC)...

This paper describes an experimental study of the stability of a hydrolyzed polyacrylamide (HPAM) polymer and an HPAM-2acrylamido-tertbutylsulfonic acid (ATBS) terpolymer in the presence of varying initial levels of dissolved oxygen (0 to 8,000 ppb), Fe2þ (0 to 220 ppm), and Fe3þ (0 to 172 ppm). A special method was developed to attain and confirm dissolved-oxygen levels. Stability studies were...