The development and optimisation of a lab-scale process for biological treatment of lignin-rich wastewater using biofilms formed by Nuerospora Discreta

Lignin is a complex biopolymer found in lignocellulosic materials used as raw material in pulp and paper making. Lignin is processed as a by-product of low value and is discarded in the wastewater. This wastewater is highly polluting due to dissolved lignin degradation products, which give it an intense colour and high chemical oxygen demand (COD), causing harm to aquatic life, plants, and animals. Removal or degradation of lignin has been shown to improve water quality in industrial wastewater, however, the complex structure of lignin makes it difficult to be degraded. Advancements in wastewater treatment methods, such as the conventional physiochemical and thermochemical methods employed, have a detrimental impact on the environment due to the production of hazardous by-products and high energy requirements. Biological treatment of lignin using fungi has the potential to overcome many of these roadblocks and lead to a successful process. This thesis aims to develop a single-step biological process for treating wastewater from the kraft process used in paper-making. Neurospora discreta, an ascomycete fungus, has been reported to degrade lignin effectively in lignocellulosic biomass, as it possesses the ligninolytic enzymatic machinery required for lignin degradation. It also has a unique ability to form robust biofilms at the air and liquid interface. In this research, N. discreta was evaluated for its ability to treat lignin-rich wastewater for the first time. The process optimisation was initially developed on synthetic wastewater using alkali lignin, followed by studies using wastewater provided by a pulp and paper-producing company. Firstly, the Taguchi statistical design of experiments, was used to identify the critical process levers for enhancing lignin degradation. Secondly, the addition of naturally formed lignin degradation intermediates in the fungal-treated wastewater spent media was evaluated as a strategy to increase lignin and COD removal. Finally, the biofilms were tested in a continuous repeated batch process, where actively metabolising mature biofilms were transferred to fresh wastewater in repeated cycles. The process was then scaled-up eightfold to tray reactors. This research has developed a fungal biofilm-based sustainable, eco-friendly and scalable alternative for lignin and COD removal in industrial wastewater. The fungal biofilm treatment proved to be efficient in removing 67.8% of standard kraft lignin in synthetic wastewater. The process efficiencies, while treating real wastewater from pulp and paper mill, were improved significantly by using lignin degradation intermediates as additives. The lignin and COD removal efficiencies of 70% were noted in cultures fed with lignin degradation intermediates compared to 57% and 50% respectively, in unfed culture. Enzyme activity for polyphenol oxidase (PPO), versatile peroxidase (VPO) and laccase were also seen where VPO was reported for the first time in a Neurospora species. The repeated-batch treatment process was evaluated and resulted in an efficient scalable process

Recent Evolutions and Trends in the Use of Computer Aided Chemical Engineering for Educational Purposes at the University of Liège

peer reviewedThe present paper addresses the evolution and perspectives in the teaching of CAPE methods in the Department of Chemical Engineering at the University of Liège. The transition that happened in the 90ies with the arrival of commercial software is highlighted, as the learning outcomes evolved from the ability of building programs to solve chemical engineering problems towards the ability to use complex commercial software and to understand their limitations. Moreover, CAPE methods were extended to non-dedicated CAPE courses, which is illustrated here by the goals and challenges of their use in courses like “Reactor Engineering” and “Life Cycle Analysis”. It was observed that students sometimes assume that CAPE softwares provide straightforward and trustworthy solutions without the need of understanding their mathematical bases and assumptions. Thus, solutions to make students aware of these limitations are proposed, including the creation of an integrated project focussing on complex multi-disciplinary issues, evidencing the need for critical input from the operator

Tratamento de águas residuais industriais com nanomateriais sintetizados para um ambiente sustentável

Quality of the final discharged effluents from industrial activities has been the subject of significant efforts over several decades to improve the performance of the methods applied for their treatment, either by physico-chemical, biological, or a combination of these processes. Among the emerging technologies, the application of various types of engineered nanomaterials (ENMs) has gained a particular attention in recent years. The present thesis aimed to carry out either experimental studies, surveys and critical reviews in order to synthesize the most sustainable nanomaterials for the treatment of recalcitrant pollutants from the content of industrial effluents. In parallel, the sustainability of other biological and physicochemical methods has been critically assessed and the most sustainable treatment methods have been suggested to be adopted by the industries. It was demonstrated in this thesis that the application of Tagguchi approach can considerably aid to control the properties of iron-based nanoscale particles synthesized by a liquidphase reduction process. Working with this system revealed that both the (reductant/Fe3+) ratio, (R), and the Fe3+concentration, [Fe3+], are the parameters that determine critical characteristics including particle crystalline phase composition, crystallinity and surface area although R has been revealed as the most important one. Nano zero valent iron particles with enhanced properties, synthesized by utilization of ultrasonic irradiation, was successfully tested to degrade organic dyes (methylene blue, as a case study) which are dominant in the wastewater from some industries such as textile factories. Recovery of the nanomaterials after being applied for the treatment purposes is also among the most important parameters for the selection and synthesis of the most sustainable nanomaterials for environmental applications. A novel ZnO/Fe3O4 on Bentonite nanocomposite prepared in this thesis showed acceptable photocatalytic decomposition of 2,4 dichlorophenol besides the ability to be recovered after being used. Magnetic nanocomposites were also tested for the degradation of AOXs from pulp and paper mill effluents and showed acceptable performance in such applications. A framework was also developed in this thesis for the sustainability assessment of the best available technologies to deal with industrial effluents, showing the efficiency of biological treatment methods to deal with industrial effluents although having some limitation to deal with phenolic industrial effluents. With a precise acclimatization process, very high efficiency for the biodegradation of phenol with a high degree of resistance to the shock of initial phenol concentration was achieved using activated sludge process. The results of a critical review, as the future outlook of this thesis, indicated the possibility of integration of engineered nanomaterials and also biological treatment with the membrane technologies in order to overcome the existing barriers for the rapid development of membrane technologies for the treatment of industrial effluents.A qualidade dos efluentes finais de atividades industriais tem sido, ao longo de várias décadas, objeto de esforços significativos para melhorar o desempenho dos seus métodos de tratamento, seja por via físico-química, biológica ou uma combinação destes. Entre as tecnologias emergentes, o recurso a nanomateriais sintetizados (ENMs) tem sido alvo de especial atenção nos últimos anos. A presente tese teve como objetivo realizar estudos experimentais, levantamentos de informação e revisões críticas, a fim de sintetizar nanomateriais sustentáveis para o tratamento de poluentes recalcitrantes existentes em efluentes industriais. Paralelamente, a sustentabilidade de outros métodos biológicos e físico-químicos foi avaliada criticamente, tendo-se sugerido os métodos de tratamento mais sustentáveis para serem adotados pelas indústrias. Foi demonstrado nesta tese que o recurso à abordagem de Tagguchi pode auxiliar consideravelmente no controlo das propriedades de partículas nanométricas à base de ferro, sintetizadas por um processo de redução em fase líquida. O estudo deste sistema revelou que tanto a razão (agente redutor/ Fe3+) como a concentração de Fe3+ são os parâmetros que determinam características críticas dos precipitados, incluindo a sua composição de fases cristalinas, grau de cristalinidade e área superficial específica. As nanopartículas de ferro de valência zero com propriedades melhoradas, sintetizadas pela utilização de irradiação por ultrasons, foram testadas com sucesso para degradar corantes orgânicos (azul de metileno como corante modelo) que são compostos dominantes nas águas residuais de algumas indústrias, designadamente de fábricas de têxteis. A recuperação dos nanomateriais após a sua aplicação em tratamentos de efluentes também é um dos aspectos mais importantes a ter em consideração na seleção e síntese de nanomateriais sustentáveis para aplicações ambientais. Um novo nanocompósito de ZnO/Fe3O4 sobre Bentonite, produzido neste trabalho, revelou uma capacidade aceitável para decomposição fotocatalítica do 2,4 diclorofenol, além da capacidade de ser recuperado após utilização. Testaram-se também nanocompósitos magnéticos na degradação de AOXs de efluentes da indústria do papel e celulose que evidenciaram um desempenho aceitável nessas aplicações. Definiu-se também nesta tese um contexto para a avaliação da sustentabilidade das melhores tecnologias disponíveis para lidar com efluentes industriais, tendo-se revelado a eficiência dos métodos de tratamento biológico para lidar com efluentes industriais, embora com alguma limitação para lidar com efluentes industriais fenólicos. Com um processo de aclimatação preciso, conseguiu-se uma eficiência muito elevada para a biodegradação do fenol, com alto grau de resistência ao choque da concentração inicial de fenol, utilizando-se o processo de lamas ativadas. Mediante uma revisão crítica da literatura, e como perspectivas de futuro a extrair do presente trabalho, aponta-se a possibilidade de integrar nanomateriais sintetizados e tratamento biológico nas tecnologias de membrana, para superar as barreiras actualmente existentes ao rápido desenvolvimento das tecnologias de membrana para o tratamento industrial efluentes.Programa Doutoral em Ciências e Engenharia do Ambient

Biofiltration of volatile compound mixtures from pulp and paper industries

[Resumen] Un biorreactor en dos etapas, consistente en un biofiltro percolador (BTF) como primera etapa y un biofiltro (BF) como segunda etapa, se operó bajo estados estacionario y transitorio, para purificar una mezcla gaseosa compuesta por sulfuro de hidrógeno, metanol y α-pineno. El sulfuro de hidrógeno y el metanol se eliminaron en la primera etapa, mientras que el α- pineno se eliminó fundamentalmente en la segunda etapa. Los biorreactores fueron sometidos a dos tipos de sobrecargas: a largo plazo (66h) con cargas bajas-medias y de corto plazo (12 horas) con altas cargas. Utilizando redes de neuronas artificiales (ANNs), se realizó un modelado para predecir las respectivas eficiencias de eliminación (EEs). Se observó que un perceptrón multicapa con topología 3-4-2 fue capaz de predecir la eliminación del H2S y del metanol en el BTF, mientras que una topología de 3-3-1 fue capaz de aproximar la eliminación del α-pineno en el BF. La misma mezcla gaseosa fue posteriormente examinada en un BTF inoculado con un consorcio microbiano altamente adaptado. Se observó que la presencia del metanol afectó negativamente a la eliminación del α-pineno, sin embargo lo opuesto no sucedió. La eliminación del α-pineno se vió afectada por su propia presencia. El H2S no mostró ningún efecto sobre la eliminación de los otros compuestos. Este BTF también fue modelado usando ANNs y fue también sometido a diferentes tipos de sobrecargas a corto plazo, de cada contaminante por separado. Para el metanol y el sulfuro de hidrógeno, se observó que estas sobrecargas no afectaron significativamente a su propia eliminación, pero la eliminación del α-pineno se vio afectada en un 50%.[Resumo] Un biorreator en dúas etapas consistente nun biofiltro percolador (BTF) como primeira etapa e nun biofiltro (BF) como segunda etapa, foi operado baixo estados estacionario e transitorio, para a purificación dunha mestura gasosa formada por sulfuro de hidróxeno, metanol e α- pineno. O sulfuro de hidróxeno e o metanol foron eliminados na primeira etapa, mentres co α- pineno foi principalmente eliminado na segunda etapa. Os biorreactores foron sometidos a dous tipos de sobrecargas: a longo prazo (66h) con cargas medias-baixas, e de curta duración (12 horas) a cargas elevadas. Utilizando redes de neuronas artificiais (ANNs), realizouse unha modelaxe para prever as correspondentes eficiencias de eliminación (EEs). Observouse que un perceptrón multicapa con topología 3-4-2 foi capaz de prever a eliminación do H2S e do metanol no BTF, mentres que unha topoloxía 3-3-1 foi quen de aproximarse á eliminación do α-pineno no BF. A mesma mestura gasosa foi examinada posteriormente nun BTF inoculado cun consorcio microbiano altamente adaptado. A presenza do metanol afectou negativamente a eliminación do α-pineno, con todo, o contrario non aconteceu. A eliminación de α-pineno, foi afectada pola súa propia presenza. O H2S non mostrou ningún efecto sobre a eliminación dos outros compostos. Este BTF tamén foi modelado utilizando ANNs e tamén foi suxeito a varios tipos de sobrecargas a curto prazo, de cada contaminante por separado. Para o metanol e o sulfuro de hidrógeno observouse que estas sobrecargas non afectaron significativamente as súas eliminacións, pero a eliminación do α-pineno foi afectada nun 50%.[Abstract] A two-stage bioreactor, comprising a biotrickling filter (BTF) as the first-stage and a biofilter (BF) as the second-stage, operated under steady-and transient-state conditions, was tested to remove gas-phase hydrogen sulphide, methanol and α-pinene. Hydrogen sulphide and methanol were removed in the first-stage, while α-pinene, was removed predominantly in the second-stage. The bioreactors were tested with two types of shock loads, long-term (66h) low to medium concentration loads, and short-term (12h) low to high concentration loads. Their performances were modelled using artifitial neural network (ANN), in order to predict the removal efficiencies (REs). It was observed that, a multi-layer perceptron with the topology 3- 4-2 was able to predict RE of methanol H2S in the BTF, while a topology of 3-3-1 was able to approximate RE of α-pinene in the BF. The same gaseous mixture was later examined in a biotrickling filter (BTF), inoculated with a highly adapted microbial consortium. The presence of methanol showed an antagonistic removal pattern for α-pinene, but the opposite did not occur. α-Pinene, removals were affected by itself. H2S did not show any declining effect on the other compounds. This BTF was also modeled using ANNs and subjected to different types of short-term shock-loads. It was observed that, short-term shock-loads of individual pollutants (methanol or hydrogen sulfide) did not significantly affect their own removal, but the removal of α-pinene was affected by 50%

Removal of Heavy Metal Ions Using Magnetic Materials

Heavy metal ions contaminate water environment through point sources and nonpoint sources. Heavy metal ions are categorized as inorganic contaminants by both the WHO and the USEPA. The heavy metal ions are increasingly being introduced into the environment as pollutants and contaminants resulting from human activities. Magnetic particles for water treatment applications have received considerable attention from researchers due to high separation efficiency. The magnetic particles behave similar to or even better than various commercial adsorbents. The magnetic particles also exhibit high selectivity for the target pollutants from the environment besides enabling ease of operation for reducing the particle separation steps from the flowing stream. A comprehensive and systematic understanding of synthesis and surface modifications of magnetic particles is significant to enhance their practicability in environmental technology. Although high removal performance and reactivity can be achieved by smaller particle size, the stability, toxicity, and recovery of the particles magnetically could be challenging. In contrast, the active surface of magnetic particles may be forfeited, while surface modifications stabilize and reduce the toxicity of the particles. Reliable surface modifications are necessarily needed for the increment of the number of active sites to remove the heavy metals. For successful environmental applications of the magnetic particles, modification on the magnetic particles is principally crucial to balance the effects on their reactivity, capacity, and reusability

Steady-state modeling of nutrient transformations in activated sludge treatment of pulp and paper wastewater

Wastewater treatment in the pulp and paper industry -- Activated sludge treatment -- Carbon & nutrient transformation mechanisms -- Data measurement, collection & processing -- Modelling : activated sludge models (ASM) -- Case study background : site & process -- Gaps in the body of knowledge, objectives hypothesis -- Wastewater Characterisation -- Mass Balance -- Modelling -- Errors Analysis -- Sensitivity Analysis -- Equivalent modelling nomenclature

Tratamento de efluentes provenientes de fábricas de pasta de papel (Processo Kraft)

A indústria da pasta e do papel uma grande utilizadora de água e, consequentemente, responsável por descarregar volumes significativos de efluentes industriais nos meios recetores. O efluente de uma fábrica de pasta de papel contém diversos contaminantes, pelo que necessita de ser devidamente tratado para que possa ser descarregado no meio recetor. Deste modo, o objetivo principal das estações de tratamento de água residual industrial (ETARI), consiste na remoção de contaminantes presentes nos efluentes, através de processos de natureza variada, nomeadamente físico-químicos, biológicos e, ou processos de tratamento integrados. Esta dissertação foi desenvolvida no âmbito de um protocolo de prestação de serviços da FCT NOVA à The Navigator Company cujo objetivo incluiu a análise dos principais processos de tratamento dos efluentes comummente utilizados no setor da produção de pasta de papel kraft. A caracterização qualitativa dos efluentes produzidos inclui, geralmente, matéria orgânica e inorgânica, halogénios orgânicos adsorvíveis (AOX) e cor. Os efluentes de uma fábrica de pasta de papel kraft são, por norma, caracterizados pela presença de CBO5, CQO, SST, AOX, Azoto total, Fósforo total e Cor, tendo sido estes os principais parâmetros analisados ao longo deste documento. Inclui uma descrição sumária dos principais processos de produção de pasta de papel, sendo igualmente abordado o uso da água na indústria da pasta e do papel e caracterizados os efluentes gerados no processo. Os operações e processos de tratamento abordados incluem as etapas de decantação e de flotação, os processos de coagulação, floculação e eletrocoagulação, a tecnologia de membranas, a adsorção e a oxidação química, os processos biológicos aeróbios e anaeróbios. São caracterizadas sumariamente as ETARI dos complexos industriais de Setúbal (CIS), Aveiro (CIA) e Figueira da Foz (CIF), onde se produz pasta de papel através do processo kraft, e que utilizam processos biológicos de lamas ativadas, e analisadas as eficiências de remoção, dos parâmetros que constam das respetivas licenças de descarga, com base na informação quantitativa e qualitativa disponibilizada. Refere-se que a otimização de alguns dos parâmetros operacionais, nomeadamente os que se referem ao processo biológico de lamas ativadas, poderá contribuir para melhorar a eficiência de remoção de alguns dos parâmetros, nomeadamente no que se refere à CQO, SST e N

MS in Environmental Science and Biology

Department to offer a Master of Science in Environmental Science; and a combined BS/MS in Environmental Science and Biology

Evaluation of environmental policy instruments : a case study of the Finnish pulp & paper and chemical industries

This research-based evaluation of environmental policy Instruments in Finland is focussed on regulatory instruments based on the Water Act, the Air Pollution Control Act and the Chemicals Act, on electricity taxation and on voluntary environmental management systems. The examined policy instruments have had several positive effects. They have directed major industrial point source polluters towards solving environmental problems. The transparency has been an important factor ensuring the success of the policy instruments and in avoiding the regulatory capture that could have thrived in a system largely based on negotiations between operators and authorities. The transparency has made it easy for Finnish firms to adopt environmental management systems and an open attitude to environmental reporting. The permit conditions have not directly resulted in innovations, but they have contributed to the diffusion of end-of-pipe technology and have contributed to innovations by expanding the market for environmentally better technical solutions. The permit systems have also indirectly contributed to innovations by creating a demand for environmental experts and environmental education.Networks have clearly developed as a consequence of and in response to regulatory instruments. These networks appear to have had their greatest significance prior to the permit procedures. The trend has been towards a greater emphasis of the communication in the networks prior to the presentation of an application in order to ensure a smoothly functioning permit process. In the networks contributing to innovations and the diffusion of innovations authorities have largely been outsiders, except when an innovation has become a de facto standard for permit conditions.The different kind of effects, the complexity of consequences and the uncertainties with respect to causes and effects mean that studies aiming at evaluating the overall worth and merit of an environmental policy instrument should never be structured from a single point of view using only one method. Multiple criteria should be used. The drawback of the multiple approach principle in evaluation is that the evaluations will run into data problems and all the difficulties of multi- and transdisciplinary research, but the multidisciplinarity is a necessary condition for developing an informed view of the functioning and effects of environmental policy instruments.This publication is the result of a project financed by the environmental cluster research programme