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The assessment key factors of any bioprocess sustainability are mainly its interaction towards the environment and the capacity to control any generated pollution, beside its social and economical aspects. These factors have direct impact on the decision-making regarding the choice of the relevant technologies at the early stages of the bioprocess design. Therefore, in the present study we assessed the environmental impact of a chosen model process, namely for the production L-lysine by fermentation using Corynebacterium glutamicum and glucose as the bacteria and the substrate, respectively. We used the Super Pro Designer® version 9.0 software to compute mass balances of the entry and exit streams. The results, together with all relevant impact categories, which are classified according to calculated mass indices, were used for environmental assessment to deduce the set environmental parameters, as environmental factors and indices. In order to optimize the environmental performance of the bioprocess, other indices were also calculated. For instance, the results showed that Water was the most influential relevant component from mass point of view with 20.97 and 22.32 kg/kg P for input and output, respectively. Regarding the fact that Water is an exhaustible natural resource, it is necessary to anticipate its recycling. Therefore, as a second step a part of the water recovered during the purification of the main product was recycled along with L-Lysine wastes. This led to important mitigations of the environmental impacts of Water and L-Lysine as well to a production increase of the latter. [ABSTRACT FROM AUTHOR]

The research study below aims to characterize the hydrodynamics of a Moving Bed Biofilm Reactor filled with Kaldnes K1. Firstly, find the type of reactor (stirrer or piston) and finally set the operating conditions for carrying out the biological denitrification in an MBBR reactor. The hydrodynamics were determined by means of pulse tracer tests and by calculating distribution curves of the residence time at different stirring speeds (100 - 300 rpm), for different support infill (0 - 165.2 g) and at different influent feed rates (0.1 - 2 L.h-1). The moving bed biofilm reactor (MBBR) showed rector behavior, it is a perfectly stirred reactor, and the optimaloperating conditions are for stirring speeds of 100 rpm, quantities of support of 165.2 gand afeed rate 0.816 L h-1. [ABSTRACT FROM AUTHOR]

The present work reports a study on the test of olive stones as an adsorbent for removal of cation Cd(II) and the oxyanion Cr(VI) from aqueous solutions. The experimental elimination of the species has been carried out batchwise and the influence of certain physico-chemical parameters such as the contact time, the pH of the solution, the temperature, the solid to liquid ratio and the agitation speed has also been considered. The equilibrium adsorption capacity of the olive stones for the case of Cr(VI) follows the Langmuir model, whereas for the Cd(II) cations, the two models -- Langmuir and Freundlich can be equally representative. The adsorption process has been found to be of pseudo second-order and the rate constants have been determined for both cations. The Gibbs free energy sign is negative for the adsorption of both cations, indicating that the process is spontaneous. Finally the olive stones retain chromium more than cadmium, but at optimal conditions, high removal percentages are reached for both cations. [ABSTRACT FROM AUTHOR]