citric acid

The kinetics of cathode reactions occurring on a gold electrode in acidic thiourea-citrate electrolytes has been studied. Using classical electrochemical methods (potentiometry, chronovoltammetry, electrogravimetry) and graphic-analytical calculations, the following were established: the instability constant of gold complexes, the type of kinetics, the nature of the delayed stage, and the main kinetic characteristics of the electrochemical reaction during gold deposition.

In the presented study, the significant operating variables regarding biosynthesis of citric acid process were assessed and their effects on the process yield were analysed. These variables, namely, initial sucrose concentration, methanol concentration, inoculum density, initial medium pH, spore age, stirrer speed, incubation period, fermentation temperature, particle size distribution, oxygen flow rate, and moisture content have significant influence on bioprocess of citric acid production.

The basic problems of development of restoration materials in Europe are considered. The basic ways of optimizing the binder compositions based on roman cement and hydraulic lime are presented and the technological parameters of formation of roman cement and hydraulic lime with marl and marlaceous limestone of Galicia are determined. The possibility of the use of additives- retarders of hydration of modified binders is showed and their influence on physical and mechanical properties of the studied compositions is established.