Modeling Biodegradation Kinetics on Benzene and Toluene and Their Mixture

The objective of this work was to model the biodegradation kinetics of toxic compounds toluene and benzene as pure substrates and in a mixture. As a control, Monod and Andrews models were used. To predict substrates interactions, more sophisticated models of inhibition and competition, and SKIP (sum kinetics interactions parameters) model were applied. The models evaluation was performed based on the experimental data from Pseudomonas putida F1 activities published in the literature. In parameter identification procedure, the global method of particle swarm optimization (PSO) was applied. The simulation results show that the better description of the biodegradation process of pure toxic substrate can be achieved by Andrews' model. The biodegradation process of a mixture of toxic substrates is modeled the best when modified competitive inhibition and SKIP models are used. The developed software can be used as a toolbox of a kinetics model catalogue of industrial wastewater treatment for process design and optimization

Improvement on the concentrated grape juice physico-chemical characteristics by an enzymatic treatment and Membrane Separation Processes

ABSTRACT In this work, the improvement on the concentrated grape juice physico-chemical characteristics by using an enzymatic treatment followed by Membrane Separation Process (MSP) has been investigated. By using Novozym 33095(r) and Ultrazym AFP L(r) enzymes varying three operating parameters, the best result on the grape pulp characteristics was attained for the Novozym 33095(r) performed at 35oC, 15 min. and 50 mgL-1. In micro/ultra filtration processes after enzymatic pretreatment, the best performance of the MSP with high permeate flux value and suitable grape juice characteristics was attained using 0.05 mm membrane pore size, 1 bar pressure and 40 oC treatment temperature. When reverse osmosis process is operated at 40 bar and 40oC, high soluble solid and low turbidity values are attained. An enzymatic treatment along with MSP has shown an alternative and efficient grape juice processing system, being possible to extend to other foods