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4 Tablas.-- 2 Figuras, Spent livestock bedding is a valuable resource for the production of green energy (methane) in rural areas. Comparison and evaluation of batch anaerobic digestion and co-digestion of different mixtures of goat straw bedding (SGSB) and goat cheese whey were carried out. Biochemical methane potential (BMP) tests of the 100% SGSB, 95% SGSB-5% whey, 90% SGSB-10% whey, 85% SGSB-15% whey and 100% whey were found to be 423 ± 7, 354 ± 9, 371 ± 2, 293 ± 1, 274 ± 2 mL CH4 g−1 VS. Two different kinetic models were evaluated. The logistic model revealed a decrease in the maximum methane production rate (Rm) from 34.7 ± 1.5 to 14.1 ± 0.9 mL CH4 g−1 VS·d−1 when the percentage of whey in the mixture increased from 0 to 15% as a consequence of the increased ammonia released during the co-digestion of increased concentrations of whey. The lowest value for the maximum methane production predicted by the model (P) was found for 100% whey (274 ± 10 mL CH4 g−1 VS). A two-substrate model was applied to describe the evident existence of rapid and slowly degradable material. Regarding the hydrolysis kinetic constants predicted by this model, considerable increases in the rapid biodegradation stage (krapid) were observed when comparing to the values found for the slow (kslow) biodegradation stage in all the cases tested. The increases between both constants rose from 5 to 42% when the percentage of whey increased., The authors wish to thank to the regional government of Andalucía, Junta de Andalucía, Consejería de Economía y Conocimiento (Project of Excellence RNM-1970) for providing financial support. N.F. Puntano also wishes to thank the academic mobility and exchange program (PIMA). The PIMA program is a mobility initiative for undergraduate students promoted by the Ibero-American States Organization. The authors also wish especially to thank Manuel Vázquez (Sierra del Romero) for his contribution.

Presented in this chapter are the fundamental principles of solution thermodynamics and process kinetics for preparation of nonsolvent-induced phase separation membranes. The principles help to explain the origin of structure asymmetry and the formation of separation layers and provide guidelines to identify the important factors involved in membrane formation and to rationalize the complicated interplay of the factors. Special attention is paid to the effects of the competition between different demixing mechanisms and the evolution of phase-separated domains on controlling membrane morphology and tailoring membrane separation performance, with stressing on the role of polymer solution gelation and how it can influence the mass transport kinetics, the solution thermodynamic instability, and the growth of phase-separated domains. The principles are then extended to clarify the roles of modification additives in membrane formation and the application of using additives to modify the structure and performance of hollow fiber membranes is also discussed.

Cements are hydraulic binders that react with water to form solidified phases; the hydration reaction plays an important role in determining the behavior of the cementitious systems through their life cycle. This chapter addresses the hydration reaction kinetics and thermodynamics and their impacts on the properties of the cement-based systems. In this respect, the hydration reactions and their roles in determining the setting time, mechanical properties, and heat release during the hydration process will be presented by overviewing the principals and advances in studying the kinetics of alite as the main and fast reacted major unhydrated cement phase. Properties of the hydrated Portland cement-based materials will be summarized, and the factors that control the hydration process will be discussed. The focus of this section is to identify the links between the factors that affect the hydration reactions and the attained cement properties. Hydration of innovative cements including calcium aluminate cement that is used for radioactive waste conditioning and is considered as a part of the low-pH cement in geological disposal will be overviewed, and main properties of these hydrated cements will be highlighted.

The reuse of industrial residue streams such as fly ash (FA) or waste materials such as recycled concrete aggregate (RCA) can be beneficial both from an economic and an ecological point of view. Extensive research, investigating different properties of these concrete types, has been carried out so far. However, durability remains a key property ensuring sustainable application of these materials in the construction sector that still needs more research to be fully understood. The main objective of this study was to evaluate the application of widely used models for carbonation depth prediction—defined for ordinary Portland cement concrete with natural aggregate (NAC)—to high volume FA concrete (HVFAC) and recycled aggregate concrete (RAC). The research presented in this paper was conducted in two steps. First, an experimental programme was designed to provide better understanding of the influence of different CO2 concentrations on the carbonation process kinetics in HVFAC, RAC and NAC. This was performed using accelerated carbonation tests (CO2 concentrations of 1%, 2%, 4% and 16%) and natural carbonation tests (duration 21 and 48 months). Furthermore, a database of previously published results of HVFAC and NAC carbonation depths was made in order to analyse the application of carbonation depth prediction defined by Tuutti and given in the fib Model Code 2010. It was shown that the existing models, providing the relationship between accelerated test results and natural carbonation depth, are applicable to NAC and RAC but not to HVFAC. Modifications of the above mentioned models were proposed in order to enable a more accurate and reliable prediction of the HVFAC carbonation depth under natural exposure conditions.

In this chapter the literature on the alkaline hydrogen peroxide (AHP) pretreatment of biomass is reviewed. The review focuses on parameters that influence the efficiency of biomass decomposition aimed at further production of biofuels. The optimal process conditions of the AHP method are discussed. Many examples are given for the application of this pretreatment method to various kinds of biomass. The mechanism of delignification by the AHP treatment is discussed, and the newest proposal for the process kinetics is given. The direction of further investigations of the AHP pretreatment are suggested.

Karataş, Mustafa Argun, Yusuf Alparslan (Aksaray, Yazar), In this work, the decolorization of C.I. Reactive Blue 114 (RB114), a commercially important anthraquinonic dye, by Fenton processes was investigated. The effects of operating parameters, such as Fe 2+:H 2O 2 ratio, pH value, reaction time and temperature were examined. Maximum decolorization (86%) efficiencies were achieved at the Fe 2+:H 2O 2 ratio of 0.1 and pH 3 for 20min reaction time. The decolorization kinetic of RB114 followed pseudo-second-order reaction kinetic. The paper also discussed thermodynamic parameters including changes in Gibbs free energy, and activation energy for the decolorization of RB114 by Fenton and exposed that the oxidation process was spontaneous under natural conditions.

9 páginas, 5 figuras, 1 tabla, In the paper, a class of bioprocesses with fully unknown kinetics is considered. Indirect adaptive control algorithm where the process kinetics is presented as unknown time-varying parameter is derived. A general procedure for optimal tuning of kinetic estimator design parameters is proposed by stability analysis of the control scheme. Theoretical results are verified by simulations of the control scheme of continuous fermentation of gluconic acid production by Aspergillus niger. In the conclusion, some other applications of proposed procedure are discussed., This paper includes results of the joint research project that is supported by the bilateral agreements between Bulgarian Academy of Sciences and CSIC – Spain; Academy of Science of Czech Republic and Academy of Science of Finland.

This chapter illustrates the influence of liquid-continuous impinging streams (LIS) on process kinetics. The existence of pressure fluctuation and the promotion of micromixing are the major features of liquid-continuous impinging streams. One of their valuable applications is the promotion of process kinetics. Strong micromixing and pressure fluctuation promote process kinetics by the mechanisms of increasing both the probability of collision and the effective collisions. Process kinetics not only depends on the nature of the substance system involved and the operating conditions but also relates to the flow configuration in the processing device employed. Comparative investigations were made for the crystal-growth kinetics of di-sodium phosphate in the impinging stream crystallizer (ISC) and the fluidized bed crystallizer (FBC), and the kinetics of ethyl acetate saponification in the submerged circulative impinging stream reactor (SCISR) and the stirred tank reactor (STR). Results suggest that the major reasons of LIS promoting process kinetics may be that the effective micromixing increases the collision probability between molecules and that the considerably strong pressure fluctuation changes the energy distribution over the molecules, causing the part of the molecules that obtains more energy to achieve the higher level required for inducing reaction.

We consider the influence of adsorption-desorption (AD) kinetics on the response of micro/nanocantilever oscillators. We utilize the calculated response to analyze an oscillator with variable mass and determine the autocorrelation function and noise power spectrum for its deflection fluctuations caused by Brownian motion (thermomechanical noise). This is done by applying the Onsager's regression hypothesis. The presented theory can be used to study the influence of the unavoidable AD processes on measurements done using atomic force microscope or micro/nanocantilever sensors as well as the AD process kinetics itself.

Disposal in deep geological formations is a potential solution for the management of high level radioactive wastes. In this context, different types of rocks such as argilite are extensively studied. The French Institute for Nuclear Protection and Safety (IPSN) have selected an argillaceous site located near Tournemire (Aveyron, France) where it has developped an experimental research program focusing on the characterization of confinement properties of argilite and on the study of their potential modifications submitted to disturbances associated to the construction of a geological waste disposal. One of this relevant disturbances is desaturation. The first step of understanding such a process consists in studying the desaturation process of the argilite and especially being able to model it in order to access to the process kinetics and spatial extension of the desaturation area. To achieve this goal, a 15 months in-situ desaturation experiment consisting in ventilating a borehole with dry air and extracting collected water was performed. The experimental and modelling results of the in-situ experiment are presented in this paper. Our results suggested that the Richard's model was well adapted to the modelling of large scale argilite desaturation.

New monitoring equipment for methanogenic activity, incorporating image processing techniques has been developed which makes good use of the fluorescent property of factor 420 contained characteristically in methanogens. In bench-scale experiments, it was demonstrated that the equipment is capable of monitoring the methanogenic activity on a real time basis in good correlation with the concentration of extracted factor 420 measured by fluorometry. Moreover, the process kinetics, in which the activity monitored: by the equipment was used as the concentration of methanogens, was investigated in order to apply the monitoring equipment to the process control. Kinetic analyses of the experimental data obtained from a complete-mixed reactor showed that the monitored activity represents well the concentration of methanogens in the continuous culture system.

Carbohydrates uptake rate, oxytetracycline and erythromycin biosynthesis rates in repeated fed batch culture (RFBC) of S. rimosus T6 and S. erythreus E-08 were studied. A mathematical model expressing main process events was developed and computer simulation data compared with the experimental ones. Satisfactory agreement of theory and experiments was attained. The proposed model can explain the process kinetics and it was successfully applied in describing the process course in industrial scale fermentors.

Poly-β-hydroxybutyrate, a wide spread bacterial reserve material is a biopolymer potentially useful for technical and research uses. The optimization of the rate of the intracellular poly-β-hydroxybutyrate synthesis under conditions of growth limitation can be achieved both by consideration of process kinetics and by use of mutants defective with respect to regulatory mechanisms. KEYWORDS Poly-β-hydroxybutyric acid, Alcaligenes eutrophus , kinetics, optimization, nutrient limitation, mutants, giant cells.