Wet Oxidation of Concentrated Wastewaters: Process Combination and Reaction Kinetic Modeling

The accumulation of aqueous pollutants is becoming a global problem. The search for suitable methods and/or combinations of water treatment processes is a task that can slow down and stop the process of water pollution. In this work, the method of wet oxidation was considered as an appropriate technique for the elimination of the impurities present in paper mill process waters. It has been shown that, when combined with traditional wastewater treatment processes, wet oxidation offers many advantages. The combination of coagulation and wet oxidation offers a new opportunity for the improvement of the quality of wastewater designated for discharge or recycling. First of all, the utilization of coagulated sludge via wet oxidation provides a conditioning process for the sludge, i.e. dewatering, which is rather difficult to carry out with untreated waste. Secondly, Fe2(SO4)3, which is employed earlier as a coagulant, transforms the conventional wet oxidation process into a catalytic one. The use of coagulation as the post-treatment for wet oxidation can offer the possibility of the brown hue that usually accompanies the partial oxidation to be reduced. As a result, the supernatant is less colored and also contains a rather low amount of Fe ions to beconsidered for recycling inside mills. The thickened part that consists of metal ions is then recycled back to the wet oxidation system. It was also observed that wet oxidation is favorable for the degradation of pitch substances (LWEs) and lignin that are present in the process waters of paper mills. Rather low operating temperatures are needed for wet oxidation in order to destruct LWEs. The oxidation in the alkaline media provides not only the faster elimination of pitch and lignin but also significantly improves the biodegradable characteristics of wastewater that contains lignin and pitch substances. During the course of the kinetic studies, a model, which can predict the enhancements of the biodegradability of wastewater, was elaborated. The model includes lumped concentrations suchas the chemical oxygen demand and biochemical oxygen demand and reflects a generalized reaction network of oxidative transformations. Later developments incorporated a new lump, the immediately available biochemical oxygen demand, which increased the fidelity of the predictions made by the model. Since changes in biodegradability occur simultaneously with the destruction of LWEs, an attempt was made to combine these two facts for modeling purposes.

Wet Oxidation of TMP Concentrated Paper Mill Process Water. Kinetics of the reaction

Työn tarkoituksena oli tutkia lämpötilan, paineen, pH:n ja katalyytin vaikutusta paperitehtaan TMP-konsentroidun prosessiveden märkähapetuksessa. Teoriaosio sisältää katsauksen sellu- ja paperiteollisuuteen, jätevesien käsittelyyn, nanosuodatuksen ja märkähapetusprosessin toimintaperiaatteet ja sovellukset hybriditeknologialle nanosuodatus-märkähapetuksessa. Empiirinen osa koostuu märkähapetuskokeista eri lämpötiloissa, paineissa, pH:ssa ja eri katalyyseillä. Työssä tutkittiin näiden vaikutusta kemialliseen hapenkulutukseen (COD), Biologiseen hapenkulutukseen (BOD), Välittömästi saatavana olevan biologisen hapenkulutukseen (IABOD), ligniiniin, täysin orgaanisen hiileen (TOC) ja rasvaliukoisten uuteaineiden (LWEs) pitoisuuteen. Tuloksina kokeellisesta työstä saatiin korkeimmat COD:n alenemat ja BOD/COD (biohajoavuus) suurimmilla lämpötilaolosuhteilla (COD:n alenema 70 % ja BOD/COD 97 % 200 °C:ssa ja hapen 10 bar osapaineella). Tutkimuksessa, jossa selvitettiin hapen osapaineen vaikutusta saatiin tuloksena, että hapen osapaineen kasvu parantaa orgaanisen kuormituksen poistoa: COD poisto oli olosuhteilla130°C, 5bar 5 %, olosuhteilla 130 °C, 15bar 15 %, olosuhteilla 170 °C, 5bar 20 % ja olosuhteilla 170 °C, 15bar 50 %. Lähes täydellinen LWEs –poisto saavutettiin 150 °C ja 10bar olosuhteilla, vaikka tässä lämpötilassa ei saavutettu korkeata orgaanisen kuormituksen poistoa. Emäksinen pH vaikutti suosivan hapettavia reaktioita, koska korkein COD:n poisto saavutettiin näissä olosuhteilla; kuitenkin alkalisen väliaineen tehokkuudelle löydettiin tärkeä lämpötilariippuvuus.

Preparatory and field work phases in the qualitative empirical research process in management: the case studies approach

Purpose: The aim of this paper is to promote qualitative methodology within the scientific community of management. The specific objective is oriented to propose an empirical research process based on case study method. This is to ensure rigor in the empirical research process, that future research may follow a similar procedure to that is proposed. Design/methodology/approach: Following a qualitative methodological approach, we propose a research process that develops according to four phases, each with several stages. This study analyses the preparatory and field work phases and their stages. Findings: The paper shows the influence that case studies have on qualitative empirical research process in management. Originality/value:. Case study method assumes an important role within qualitative research by allowing for the study and analysis of certain types of phenomena that occur inside organisations, and in respect of which quantitative studies cannot provide an answer.

The role of management accounting in the process of innovation: A field work perspective

A Work Project, presented as part of the requirements for the Award of a Masters Degree in Finance from the NOVA – School of Business and Economics

Productivity in southern European small firms: When and how work organization complements process innovation

The aim of this paper is to analyse the effects of human capital, advanced manufacturing technologies (AMT), and new work organizational practices on firm productivity, while taking into account the synergies existing between them. This study expands current knowledge in this area in two ways. First, in contrast with previous works, we focus on AMT and not ICT (information and communication technologies). Second, we use a unique employer-employee data set for small firms in a particular area of southern Europe (Catalonia, Spain). Using a small firm data set, allows us to analyse the particular case of small and medium enterprises, since we cannot assume they have the same characteristics as large firms. The results provide evidence in favor of the complementarity hypothesis between human capital, advanced manufacturing technologies, and new work organization practices, although we show that the complementarity effects depend on what type of work organization practices are used by a firm. For small and medium Catalan firms, the only set of work organization practices that improve the benefits of human capital and technology investment are those practices which are more quality oriented, such as quality circles, problem-solving groups or total quality management.

Higher education in nursing: the faculty work process in different institutional contexts

Objective To analyze the characteristics of faculty work in nursing higher education. Method An exploratory qualitative study with a theoretical-methodological framework of dialectical and historical materialism. The faculty work process was adopted as the analytical category, grounded on conceptions of work and professionalism. Semi-structured interviews were conducted with 24 faculty members from three higher education institutions in the city of São Paulo, classified according to the typology of institutional contexts. Results The faculty members at these higher education institutions are a heterogeneous group, under different working conditions. Intensification and precarious conditions of the faculty work is common to all three contexts, although there are important distinctions in the practices related to teaching, research and extension. Conclusion Faculty professionalization can be the starting point for analyzing and coping with such a distinct reality of faculty work and practice.


The reception of Eugen Wüster’s work and the development of terminology

L’objectif principal de cette thèse est d’explorer et d’analyser la réception de l’œuvre d’Eugen Wüster afin d’expliquer comment ses travaux ont influencé le développement disciplinaire de la terminologie. Du point de vue historique, les travaux de Wüster, en particulier la Théorie générale de la terminologie, ont stimulé la recherche en terminologie. Malgré des opinions divergentes, on s’entend pour reconnaître que les travaux de Wüster constituent la pierre angulaire de la terminologie moderne. Notre recherche vise spécifiquement à explorer la réception de l’œuvre wüsterienne en étudiant les écrits relatifs à cette œuvre dans la littérature universitaire en anglais, en espagnol et en français entre 1979 et 2009, en Europe et en Amérique. Réalisée dans le cadre du débat sur la réception de l’œuvre de Wüster, cette étude se concentre exclusivement sur l’analyse des critiques et des commentaires de son œuvre. Pour ce faire, nous avons tenu compte de la production intellectuelle de Wüster, de sa réception positive ou négative, des nouvelles approches théoriques en terminologie ainsi que des études portant sur l’état de la question en terminologie entre 1979 et 2009. Au moyen d’une recherche qualitative de type exploratoire, nous avons analysé un corpus de textes dans lesquels les auteurs : a. ont cité textuellement au moins un extrait d’un texte écrit par Wüster ; b. ont référé aux travaux de Wüster dans la bibliographie de l’article ; ou c. ont fait un commentaire sur ces travaux. De cette manière, nous avons cerné les grandes lignes du débat autour de la réception de son œuvre. Les résultats de notre étude sont éloquents. Ils offrent une idée claire de la réception des travaux de Wüster dans la communauté scientifique. Premièrement, Wüster représente une figure centrale de la terminologie moderne en ce qui concerne la normalisation terminologique. Il fut le premier à proposer une théorie de la terminologie. Deuxièmement, la contextualisation appropriée de son œuvre constitue un point de départ essentiel pour une appréciation éclairée et juste de sa contribution à l’évolution de la discipline. Troisièmement, les résultats de notre recherche dévoilent comment les nouvelles approches théoriques de la terminologie se sont adaptées aux progrès scientifiques et techniques. Quatrièmement, une étude menée sur 166 articles publiés dans des revues savantes confirme que l’œuvre de Wüster a provoqué des réactions variées tant en Europe qu’en Amérique et que sa réception est plutôt positive. Les résultats de notre étude font état d’une tendance qu’ont les auteurs de critiquer les travaux de Wüster avec lesquels, dans la plupart des cas, ils ne semblent cependant pas être bien familiarisés. La « méthodologie des programmes de recherche scientifique », proposée par Lakatos (1978) et appliquée comme un modèle interprétatif, nous a permis de démontrer que Wüster a joué un rôle décisif dans le développement de la terminologie comme discipline et que la terminologie peut être perçue comme un programme de recherche scientifique. La conclusion principale de notre thèse est que la terminologie a vécu des changements considérables et progressifs qui l’ont aidée à devenir, en termes lakatosiens, une discipline forte tant au plan théorique que descriptif.

Modeling Of Work-Related Musculoskeletal Disorders In Chemical Process Industry In India

In this modern complex world, stress at work is found to be increasingly a common feature in day to day life. For the same reason, job stress is one of the active areas in occupational health and safety research for over last four decades and is continuing to attract researchers in academia and industry. Job stress in process industries is of concern due to its influence on process safety, and worker‘s safety and health. Safety in process (chemical and nuclear material) industry is of paramount importance, especially in a thickly populated country like India. Stress at job is the main vector in inducing work related musculoskeletal disorders which in turn can affect the worker health and safety in process industries. In view of the above, the process industries should try to minimize the job stress in workers to ensure a safe and healthy working climate for the industry and the worker. This research is mainly aimed at assessing the influence of job stress in inducing work related musculoskeletal disorders in chemical process industries in India

The work and health process in the sugarcane agroindustry in Franca, Brazil

This study aimed to discuss the interrelation between social determinants and the health conditions of workers in the sugarcane agroindustry in the region of Franca, in the countryside of São Paulo State, Brazil, from 2005 to 2006, considering the present socio-economic, historical, political and cultural conditions.

Genetic Algorithms (Binary and Real Codes) for the Optimisation of a Fermentation Process for Butanol Production

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

An alternative process for butanol production: Continuous flash fermentation

The objective of this work is to introduce and demonstrate the technical feasibility of the continuous flash fermentation for the production of butanol. The evaluation was carried out through mathematical modeling and computer simulation which is a good approach in such a process development stage. The process consists of three interconnected units, as follows: the fermentor, the cell retention system (tangential microfiltration) and the vacuum flash vessel (responsible for the continuous recovery of butanol from the broth). The efficiency of this process was experimentally validated for the ethanol fermentation, whose main results are also shown. With the proposed design the concentration of butanol in the fermentor was lowered from 11.3 to 7.8 g/l, which represented a significant reduction in the inhibitory effect. As a result, the final concentration of butanol was 28.2 g/l for a broth with 140 g/l of glucose. Solvents productivity and yield were, respectively, 11.7 g/l.h and 33.5 % for a sugar conversion of 95.6 %. Positive aspects about the flash fermentation process are the solvents productivity, the use of concentrated sugar solution and the final butanol concentration. The last two features can be responsible for a meaningful reduction in the distillation costs and result in environmental benefits due to lower quantities of wastewater generated by the process. © 2008 Berkeley Electronic Press. All rights reserved.

Unraveling the structure of sugarcane bagasse after soaking in concentrated aqueous ammonia (SCAA) and ethanol production by Scheffersomyces (Pichia) stipitis

Abstract Background Fuel ethanol production from sustainable and largely abundant agro-residues such as sugarcane bagasse (SB) provides long term, geopolitical and strategic benefits. Pretreatment of SB is an inevitable process for improved saccharification of cell wall carbohydrates. Recently, ammonium hydroxide-based pretreatment technologies have gained significance as an effective and economical pretreatment strategy. We hypothesized that soaking in concentrated aqueous ammonia-mediated thermochemical pretreatment (SCAA) would overcome the native recalcitrance of SB by enhancing cellulase accessibility of the embedded holocellulosic microfibrils. Results In this study, we designed an experiment considering response surface methodology (Taguchi method, L8 orthogonal array) to optimize sugar recovery from ammonia pretreated sugarcane bagasse (SB) by using the method of soaking in concentrated aqueous ammonia (SCAA-SB). Three independent variables: ammonia concentration, temperature and time, were selected at two levels with center point. The ammonia pretreated bagasse (SCAA-SB) was enzymatically hydrolysed by commercial enzymes (Celluclast 1.5 L and Novozym 188) using 15 FPU/g dry biomass and 17.5 Units of β-glucosidase/g dry biomass at 50°C, 150 rpm for 96 h. A maximum of 28.43 g/l reducing sugars corresponding to 0.57 g sugars/g pretreated bagasse was obtained from the SCAA-SB derived using a 20% v/v ammonia solution, at 70°C for 24 h after enzymatic hydrolysis. Among the tested parameters, pretreatment time showed the maximum influence (p value, 0.053282) while ammonia concentration showed the least influence (p value, 0.612552) on sugar recovery. The changes in the ultra-structure and crystallinity of native SCAA-SB and enzymatically hydrolysed SB were observed by scanning electron microscopy (SEM), x-ray diffraction (XRD) and solid-state 13C nuclear magnetic resonance (NMR) spectroscopy. The enzymatic hydrolysates and solid SCAA-SB were subjected to ethanol fermentation under separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF) by Scheffersomyces (Pichia) stipitis NRRL Y-7124 respectively. Higher ethanol production (10.31 g/l and yield, 0.387 g/g) was obtained through SSF than SHF (3.83 g/l and yield, 0.289 g/g). Conclusions SCAA treatment showed marked lignin removal from SB thus improving the accessibility of cellulases towards holocellulose substrate as evidenced by efficient sugar release. The ultrastructure of SB after SCAA and enzymatic hydrolysis of holocellulose provided insights of the degradation process at the molecular level.