The article shows an integrated approach for the improvement of progesterone 11?-hydroxylation. After preliminary studies on the effects on Rhizopus nigricans morphology, fungal pellets of a desired size and structure could be obtained, which further enabled its continuous use in the process of biotransformation. In order to develop an integrated biotransformation process, a continuous two-liquid phase extraction within microchannel device has been set up, where very efficient steroid extraction was achieved within a few seconds.
COBISS.SI-ID: 33681925
The enzymatic oxidation of cholesterol to 4-cholesten-3-one performed within microchannels by cholesterol oxidase, was studied in a two-phase system. A mathematical model comprising reaction kinetics and the velocity profile of two immiscible fluids, was developed. The suitable adjustment of the fluid flow rates allowed the phase separation at the Y-shaped exit from the microreactor and thereby enabled in situ product separation from the aqueous phase containing the enzyme.
COBISS.SI-ID: 33911813
The physical processes controlling the desorption of some elements from soils in a continuous leaching system representing the human stomach are investigated by fitting experimental data to a mathematical model. Soil samples from Cornwall, UK, were intimately contacted with artificial gastric solution at various flow rates. The leaching profiles of the various elements were fitted to a mathematical model incorporating two mass transfer processes. A system of partial differential equations was solved numerically with a finite difference discretization of the computational domain.
COBISS.SI-ID: 4448538
The paper is focused on investigation of different treatment procedures for the removal of toxic fractions from a landfill leachate, which could not be treated biologically due to its toxicity and persistency. The applied methods were air stripping, adsorption to activated carbon and zeolite clinoptiolite and Fenton oxidation. It has been determined, that no method alone is efficient enough for complete treatment of landfill leachate and that biotests are necessary supplements for complete evaluation of treatment efficiency.
COBISS.SI-ID: 33885701
The investigation of kinetics and efficiency of Fenton and ozonation processes for pretreatment of two landfill leachates is presented. Higher reaction rate values of Fenton´s oxidation were achieved with fresh leachate samples. Ozonation was more effective in the case of mature leachate. The best fits of experimental data from oxidation of both leachates were reached by combined kinetic model. No investigated method resulted as effective enough to be used as a pretreatment method, because they did not reduce toxicity and improve biodegradability enough to be followed by biological treatment.
COBISS.SI-ID: 33642501