Natural waste materials containing chitin as adsorbents for textile dyestuffs: batch and continuous studies

In this work three natural waste materials containing chitin were used as adsorbents for textile dyestuffs, namely the Anodonta (Anodonta cygnea) shell, the Sepia (Sepia officinalis) and the Squid (Loligo vulgaris) pens. The selected dyestuffs were the Cibacron green T3G-E (CI reactive green 12), and the Solophenyl green BLE 155% (CI direct green 26), both from CIBA, commonly used in cellulosic fibres dyeing, the most used fibres in the textile industry. Batch equilibrium studies showed that the materials’ adsorption capacities increase after a simple and inexpensive chemical treatment, which increases their porosity and chitin relative content. Kinetic studies suggested the existence of a high internal resistance in both systems. Fixed bed column experiments performed showed an improvement in adsorbents’ behaviour after chemical treatment. However, in the column experiments, the biodegradation was the main mechanism of dyestuff removal, allowing the materials’ bioregeneration. The adsorption was strongly reduced by the pore clogging effect of the biomass. The deproteinised Squid pen (grain size 0.500–1.41 mm) is the adsorbent with highest adsorption capacity (0.27 and 0.037 g/g, respectively, for the reactive and direct dyestuffs, at 20ºC), followed by the demineralised Sepia pen and Anodonta shell, behaving like pure chitin in all experiments, but showing inferior performances than the granular activated carbon tested in the column experiments.

An evaluation of fibrous structure and physical characteristics of Cutia nut (Couepia edulis Prance) shell

The Cutia-nut (Couepia edulis Prance), a species originally from the Amazon region, has a kernel with reasonable nutritional value and a hard and thick woody shell that constitute most of the fruit. After the kernel removal, the shells are regarded as waste. The possibility of using such shells, as raw material for burning or charcoal production, as well as milled residue for structural reinforcement materials is quite feasible, considering environmental and economical aspects. There is, however, a complete lack of characterization of the Cutia-nut shell and other similar species which can aggregate desirable qualities for application as engineering material. In this study some analyses are presented aiming at providing information for potential uses of these residues. In general, the shells follow a regular shape with certain dimensional proportionality to the kernel. The shell is a fibrous material with high lignin content, present low water absorption and high resistance to natural degradation.

Utilization Of Weeds And Agriwaste By Popularizing Handpapermaking In Kerala, India

Kerala in south India grows several cash crops such as banana and pineapple, the crop residues of which are sources of natural fibres that can be used in hand papermaking. Kerala, however, does not have a tradition in hand papermaking. The following is an account of an attempt to popularize the art and craft of hand papermaking among self-help groups as a means of self-employment and waste utilization, using fibres extracted from agriwaste and local plants

Wooden packaging waste reuse and refining

The aim of the thesis was both to study wooden packaging waste reuse and refining generated in the forestry machine factory environment, and to find alternative wooden packaging waste utilization options in order to create a new operating model which would decrease the overall amount of waste produced. As environmental and waste legislation has become more rigid and companies' own environmental management systems’ requirements and control have increased, companies have had to consider their environmental aspects more carefully. Companies have to take into account alternative ways of reducing waste through an increase in reuse and recycling. A part of this waste is from different forms of packaging. In the metal industry the most heavily used packaging material is wooden packaging, as such material is heavy and the packaging has to be able to bear heavy stress. In the theoretical part of the thesis, the requirements of packaging and packaging waste legislation, as well as environmental management systems governing companies’ processing of their packaging waste, are studied. The theoretical part includes a process study of systems, which direct packaging waste and wooden packaging waste refining. In addition, methods related to the continuous improvement of these processes are introduced. This thesis concentrates on designing and creating a new operating model in relation to wooden packaging waste processing. The main target was to find an efficient model in order to decrease the total amount of wooden packaging waste and to increase refining. The empirical part introduces methods for approaches to wooden packaging waste re-utilization, as well as a description of a new operating model and its impact.

Valorization and recycling of waste biomass and bioplastics into molecules, polymers and catalysts

The enormous amount of goods that world societies consume every day, derives from an immense consumption of energy and raw materials, and leads to an unthinkable amount of wastes. The abuse of fossil-based resources and the mismanaged waste is leading to big environmental pollution and climate change, with consequences on all living beings. To solve this issue and start living in equilibrium with nature, modern societies must stop using fossil fuels massively in favor to clean renewable energies, recycling, and biomass and waste utilization for materials and chemical production. Moreover, bioplastic recycling must be prioritized over their biodegrading and composting. This work is dedicated to the study of new synthetic strategies that fall into these fields.

Paperinkeräysyhtiön ympäristölupa sekä energiajakeen vastaanoton, haketuksen ja hyötykäytön suunnittelu ja kannattavuuden arviointi

Papinniemi Oy harjoittaa paperiteollisuuskuidun jatkojalostus- ja paperinkeräystoimintaa. Yhteensä raaka-ainetta tulee käsiteltäväksi noin 10 000 t/a. Työn tavoitteena oli uudistaa yhtiön jätelain (1072/1993) 42 §:n mukainen jätelupa hakemalla toiminnalle uusi ympäristönsuojelulain (86/2000)mukainen ympäristölupa. Lupahakemus toimitettiin Kaakkois-Suomen ympäristökeskuksen Lap-peenrannan toimipisteeseen 22.6.2006. Hakemuksen kuulutusajan ja lausuntokierroksen jälkeen ympäristökeskus teki asiasta myönteisen ympäristölupapäätöksen 1.11.2006. Lupapäätöksen kuulu-tusaika on 30 päivää, jonka jälkeen päätös saa lainvoiman, ellei siitä valiteta. Papinniemi Oy:n tulee tehdä hakemus lupamääräysten tarkistamiseksi 30.6.2017 mennessä. Papinniemi Oy aikoo tulevaisuudessa laajentaa toimintaansa energiajakeen vastaanotto- ja kierrä-tyspolttoaineen valmistustoimintaan. Työn toisena tavoitteena oli laatia suunnitelma ja kannatta-vuuslaskelma ko. toiminnan aloittamiseksi. Saatujen tulosten perusteella kierrätyspolttoaineen val-mistus on kannattavaa, mikäli energiajakeen saatavuus Imatran seudulla on vähintään 1700 t/a. Täl-löin yhden kierrätyspolttoainetonnin valmistuskustannus on 90 ¤. Kustannus vastaa edullisimman Imatralla kilpailevaa toimintaa harjoittavan yrityksen energiajakeen vastaanottohintaa. Polttokel-poista jätettä tuottaville yrityksille tehdyn kyselyn perusteella energiajakeen saatavuus Imatran seu-dulla on noin 3000 t/a, jolloin yhden kierrätyspolttoainetonnin valmistuskustannus on 51,49 ¤. Vaikka kierrätyspolttoaineen hinta romahti EU:n jätteenpolttodirektiivin (2000/76/EY) vaatimusten voimaantulon myötä vuoden 2006 alussa, tullee kierrätyspolttoaineen hinta nousemaan lähivuosina takaisin direktiiviä edeltäneelle tasolle (24 ¤/t). Tällöin energiajakeen vastaanottohinta toiminnan kannattavuusrajalla on 27,49 ¤/t. Kierrätyspolttoaineiden käyttöä tulevaisuudessa lisännee muiden polttoaineiden hinnan nousu, meneillään olevakierrätyspolttoaineiden standardisoimistyö, jätteiden hyödyntämisasteen parantamistavoitteet, jätteiden kaatopaikkasijoituskustannusten nousu ja päästö-kaupan vaikutus.

Creating carbon footprint calculating tool for plastic packaging products

The environmental challenges of plastic packaging industry have increased remarkably along with climate change debate. The interest to study carbon footprints of packaging has increased in packaging industry to find out the real climate change impacts of packaging. In this thesis the greenhouse gas discharges of plastic packaging during their life cycle is examined. The carbon footprint is calculated for food packaging manufactured from plastic laminate. The structure of the laminate is low density polyethylene (PE-LD) and oriented polypropylene (OPP), which have been joined together with laminating adhesive. The purpose is to find out the possibilities to create a carbon footprint calculating tool for plastic packaging and its usability in a plastic packaging manufacturing company. As a carbon footprint calculating method PAS 2050 standard has been used. In the calculations direct and indirect greenhouse gas discharges as well as avoided discharges are considered. Avoided discharges are born for example in packaging waste utilization as energy. The results of the calculations have been used to create a simple calculating tool to be used for similar laminate structures. Although the utilization of the calculating tool is limited to one manufacturing plant because the primary activity data is dependent of geographical location and for example the discharges of used energy in the plant. The results give an approximation of the climate change potential caused by the laminate. It is although noticed that calculations do not include all environmental impacts of plastic packaging´s life cycle.

Toisen jäte on toisen raaka-aine – Kierrätys ja uudelleenvalmistus taloudellisesti ja ekologisesti kestävänä liiketoimintamahdollisuutena

Toisen jäte on toisen raaka-aine – Kierrätys ja uudelleenvalmistus taloudellisesti ja ekologisesti kestävänä liiketoimintamahdollisuutena Väitöskirjatutkimus tarkastelee kierrätystä ja uudelleenvalmistusta sekä siihen perustuvaa kierrätysliiketoimintaa taloudellisesti ja ekologisesti kestävänä liiketoimintamahdollisuutena. Tässä kestävyys tarkoittaa jätekysymysten ratkaisemista tavalla, joka mahdollistaa kestävän kehityksen periaatteiden mukaisen yhteiskunnan kehittymisen. Jätteisiin liittyvät taloudelliset ja ekolo- giset kysymykset ovat merkittävä yhteiskunnallinen haaste. Tämä luo tarpeen tutkimukselle, jonka lähtökohtana on jätekysymysten moniulotteinen tarkas- telu ja yksittäisen yrityksen toiminnan suhteuttaminen osaksi laajempaa kokonaisuutta. Tässä tutkimuksessa jätteen hyödyntämistä materiaalina lähestytään sekä empiirisesti yrityksen näkökulmasta että teoreettisesti systeemiajattelun tarjoamasta laajemmasta perspektiivistä. Tutkimuksen tavoitteena on ymmär- tää kierrätystä ja uudelleenvalmistusta liiketoimintamahdollisuutena, niiden merkitystä yrityksessä, alueella ja kierrätystaloudessa sekä näiden vuorovai- kutteista suhdetta taloudelliseen ja ekologiseen kestävyyteen nähden. Tutki- muskysymys on tärkeä, koska siihen vastaamalla syvennetään ymmärrystä yrityksissä tapahtuvan kierrätyksen ja uudelleenvalmistuksen merkityksestä kestävämmän yhteiskunnan rakentumisessa. Tutkimuksen teoriaperusta pohjautuu teollisen ekologian kirjallisuuteen ja ekoteollisen kehityksen tutkimukseen. Kierrätysliiketoiminnan kestävyyden tarkastelu rakentuu tutkimuksessa teollisen ekologian ja ekoteollisen kehityk- sen lähtökohtana olevaan win-win-ajatteluun, jonka mukaan hyvä ympäristö- suorituskyky ja hyvä taloudellinen suorituskyky voivat vahvistaa toisiaan. Kierrätysliiketoiminnan teoreettisessa tarkastelussa keskeisiä elementtejä ovat kierrätystalouden malli, teollisen ekologian alueelliset systeemit, ekoteolliset verkostot ja yrityksen rooli teollista ekologiaa soveltavana toimijana. Tutki- muksen keskeisenä kontribuutiona on yritysnäkökulman integroiminen aiem- paa vahvemmin osaksi teollisen ekologian diskursseja. Kierrätysliiketoiminnan taloudelliseen ja ekologiseen kannattavuuteen ja sen myötä kestävyyteen liittyviä kysymyksiä on lähestytty tekemällä yritys- haastatteluja ja hyödyntämällä valmista haastatteluaineistoa. Tutkimusta varten haastattelin 10 kierrätysliiketoimintaa harjoittavaa yritystä vuosina 2007 ja 2008. Tämän lisäksi tutkimuksessa on hyödynnetty Turun ammatti- korkeakoulun ja Turku Science Parkin toteuttamassa RESU-hankkeessa (Kierrätysliiketoiminta ja resurssitehokkuus Varsinais-Suomen vahvuudeksi – RESU) vuosina 2013 ja 2014 kerättyä aineistoa. Hankkeessa haastateltiin yhteensä 25 jätemateriaalia hyödyntävää ja/tai tuottavaa yritystä. Aineistojen analysointimenetelmänä on sisällönanalyysi. Analyysin tulok- sena muodostettiin yhteensä viisi pääteemaa ja 12 alateemaa. Teemat kuvaavat kierrätysliiketoimintaa aiempaa moniulotteisemmin ja näin syventävät ymmär- rystä ilmiön merkityksestä kestävämmän yhteiskunnan rakentumisessa. Teolli- sen ekologian alaan kuuluvat kvalitatiiviset tutkimukset ovat melko harvinai- sia, joten tämän väitöstutkimuksen ilmeisenä vahvuutena on laadullisen tutkimusmenetelmän hyödyntäminen. Tutkimuksen tuloksena voidaan todeta, että kierrätystalouden kehittymistä edistävä kierrätysliiketoiminta on monimuotoista ja sisältää erilaisia liiketoi- mintamahdollisuuksia sekä arvoketjuja. Paikallistuntemus ja keskeinen sijainti jätemateriaalien tuottajien suhteen on tärkeä kriteeri kierrätysliiketoiminnassa, mutta jätemateriaaleja myös kuljetetaan pitkiä matkoja. Paikallisia tai alueelli- sia jätevirtoja hyödyntävä kierrätysliiketoiminta voi tukea alueellista kestä- vyyttä, mutta toisinaan myös keskitetty hyödyntäminen voi olla kestävä vaih- toehto. Yhteistyöverkostot ovat tärkeitä jätemateriaalin laadun ja saatavuuden näkökulmasta. Tutkimus osoittaa, että kierrätysliiketoimintaa harjoittavat yritykset ovat samalla sekä kierrätystalouden käytännön toimeenpanijoita että uuden toimintakulttuurin luojia. Tutkimuksen tulosten perusteella voidaan esittää johtopäätös, että kierrä- tysliiketoiminta on taloudellisesti ja ekologisesti kannattava liiketoimintamah- dollisuus. Win-win-ratkaisut eivät kuitenkaan takaa kierrätysliiketoiminnan kestävyyttä. Kierrätysliiketoiminnan kestävyyden arvioiminen edellyttää laajaa perspektiiviä ja toiminnan vaikutusten suhteuttamista mittakaavaan, ajalliseen ulottuvuuteen, interventioon ja sosiaalisiin kysymyksiin. Teolliseen ekologiaan perustuva kierrätysliiketoiminta luo mahdollisuuksia edistää kestävyyttä, joten tällä perusteella kierrätystä ja uudelleenvalmistusta voidaan pitää kestävänä liiketoimintamahdollisuutena. Avainsanat: kierrätysliiketoiminta, kierrätys, uudelleenvalmistus, systeemiajattelu, teollinen ekologia, ekoteollinen kehitys, kierrätystalous, win-win-ajattelu, kestävyys One company's waste is another's raw material –Recycling and remanufacturing as an economically and environmentally sustainable business opportunity The thesis investigates whether product recycling and remanufacturing can serve as a business opportunity that is economically and ecologically sustaina- ble. In this effort, my idea is to contribute to solving the waste issue in a manner that makes it possible to strive toward sustainable societal develop- ment. The economic and ecological questions associated with waste flows are a significant challenge. The complexity of the issue requires a multidimen- sional approach in which the operation of an individual company is viewed in the context of the larger societal system. In this thesis waste utilization as a resource with value is considered both from an empirical perspective on the firm as well as from a more general viewpoint offered by systems analysis. The objective of the thesis is to under- stand recycling and remanufacturing as a business opportunity. The thesis considers the meaning of recycling and remanufacturing for a single company, for the region the company is located and for the recycling economy. The objective of this study is important for it enhances the understanding of the product recycling and remanufacturing processes that take place within busi- ness organizations and how these processes affect societal sustainable development. The theoretical basis arises from industrial ecology and from the literature on eco-industrial development. The business-economic win-win situation and this vision serve as the basic position from which recycling business is inves- tigated in the thesis. In the theoretical discussion, key elements are recycling economy model, regional and local industrial ecosystems, eco-industrial networks and the role of a company as an actor that applies industrial ecology in practice. The main contribution of this study lies in integrating the company perspective more strongly into the industrial ecology discourses. The recycling business has been studied by conducting interviews in companies and by secondary analysis of an existing interview material. During 2007 and 2008 I made 10 interviews in companies that are active in recycling business. In addition, I used interview material gathered for the project “Recycling business and resource efficiency as the strength of Southwest Finland” (RESU) by Turku University of Applied Sciences and Turku Science Park during the period 2013–2014. This data covers altogether 25 businesses that either utilize and/or produce waste materials. The data has been analyzed using the content analysis method. This process led to the development of 5 main themes and 12 sub-themes. These themes describe the recycling business multi-dimensionally and thus understanding of the phenomenon and its role in building a sustainable society are substantially deepened in this research. In the field of industrial ecology qualitative studies are relatively rare and therefore the qualitative research approach is an evident strength of the thesis. The results show that the recycling business activity supporting recycling economy has diverse dimensions including various business opportunities and diverse value chains. The results show that for waste producers it is important to know the local situational factors and to have a central geographical location. Waste materials are, however, transported over long distances as well. The study indicates that local waste flow utilization can support regional sustainability, while occasionally a more centralized utilization can be sustain- able. Collaboration networks are important to secure the quality and availabil- ity of utilizable waste materials. The thesis demonstrates that the companies practicing recycling business serve simultaneously as actors that implement recycling economy and enhance a new operation culture within the business community. The overall conclusion of the thesis argues that recycling business is a business opportunity that can support both an economically and environmen- tally viable business operation. However, win-win solutions do not secure the sustainability of recycling business. The sustainability evaluation of recycling business requires a holistic systems perspective. The actions undertaken need to be considered with changing spatial and temporal system boundaries, societal intervention and placed in the context of relevant societal issues. Industrial ecology -based recycling business creates opportunities for sustain- ability and thus recycling and remanufacturing present an opportunity for sustainable business. Keywords: Recycling business; Recycling; Remanufacturing, Systems thinking; Industrial ecology; Eco-industrial development; Recycling Economy; Win-Win thinking; Sustainability

Effect of C/N Ratio and Physicochemical Conditions on the production of Rhamnolipids by Pseudomonas Aeruginosa LBI

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Revisiting privatization, foreign investment, international arbitration, and water

Includes bibliography

Microwave-assisted solvent extraction and analysis of shikimic acid from plant tissues.

A better method for determination of shikimate in plant tissues is needed to monitor exposure of plants to the herbicide glyphosate [N-(phosphonomethyl)glycine] and to screen the plant kingdom for high levels of this valuable phytochemical precursor to the pharmaceutical oseltamivir. A simple, rapid, and efficient method using microwave-assisted extraction (MWAE) with water as the extraction solvent was developed for the determination of shikimic acid in plant tissues. High performance liquid chromatography was used for the separation of shikimic acid, and chromatographic data were acquired using photodiode array detection. This MWAE technique was successful in recovering shikimic acid from a series of fortified plant tissues at more than 90% efficiency with an interference-free chromatogram. This allowed the use of lower amounts of reagents and organic solvents, reducing the use of toxic and/or hazardous chemicals, as compared to currently used methodologies. The method was used to determine the level of endogenous shikimic acid in several species of Brachiaria and sugarcane (Saccharum officinarum) and on B. decumbens and soybean (Glycine max) after treatment with glyphosate. The method was sensitive, rapid and reliable in all cases.

Análisis de tecnologías eco eficientes para la disposición final de residuos sólidos en las empresas Coraseo S.A y Seacor S.A

Los residuos sólidos como consecuencia directa de las actividades humanas, han representado un reto desde sus inicios, de ahí se empezaron a desarrollar técnicas y prácticas para garantizar una adecuada gestión de los residuos, nuestros primeros ancestros encontraron en los botaderos a cielo abierto la solución más fácil para disponer los desechos de animales y residuos de comida en sitios cercanos a sus viviendas, por ejemplo, los griegos poseen registros de la inauguración del primer relleno municipal en la ciudad de Atenas hace más de 2000 años. La evolución de las culturas, la revolución industrial y el crecimiento poblacional acelerado han modificado no solo la composición sino también la cantidad de los residuos sólidos producidos, haciendo cada día más difícil su adecuada gestión debido a su alto grado de toxicidad, la ausencia de materiales biodegradables y su volumen, traduciendo esto en un gran impacto. El panorama no es muy alentador y los pronósticos emitidos por el Banco Mundial prevén que para el año 2025 los niveles mundiales de residuos sólidos urbanos alcanzaran 2,2 millones de toneladas por año. Basada en el interés por la adecuada gestión de los residuos y la disminución del impacto ambiental de las empresas Coraseo S.A y Seacor S.A, la presente investigación busca seleccionar la metodología y/o tecnología más apropiada teniendo en cuenta las condiciones económicas, logísticas y de infraestructura de la empresa y la comunidad involucrada. En primera instancia se estudió en profundidad el panorama empresarial y posteriormente se seleccionó un grupo de cuatro propuestas para la transformación y aprovechamiento de los residuos sólidos que fueron evaluadas a nivel económico, normativo, medio ambiental. Los datos analizados sugieren entre otras cosas, un robustecimiento del marco legal ambiental colombiano y mundial, una mayor colaboración económica de los organismos internacionales y las entidades bancarias y finalmente una reducción en los costos de las tecnologías disponibles para el aprovechamiento de los residuos sólidos, haría posible el sueño de las sociedades de gestionar efectivamente los residuos sólidos generando el menor impacto ambiental posible y en el caso del grupo empresarial Cordobés lograr innovar y emprender con un proyecto eco eficiente como el que se evaluó.

Utilization of waste expanded polystyrene: Blends with silica-filled natural rubber

Expanded polystyrene (EPS) constitutes a considerable part of thermoplastic waste in the environment in terms of volume. In this study, this waste material has been utilized for blending with silica-reinforced natural rubber (NR). The NR/EPS (35/5) blends were prepared by melt mixing in a Brabender Plasticorder. Since NR and EPS are incompatible and immiscible a method has been devised to improve compatibility. For this, EPS and NR were initially grafted with maleic anhydride (MA) using dicumyl peroxide (DCP) to give a graft copolymer. Grafting was confirmed by Fourier Transform Infrared Spectroscopy (FTIR) spectroscopy. This grafted blend was subsequently blended with more of NR during mill compounding. Morphological studies using Scanning Electron Microscopy (SEM) showed better dispersion of EPS in the compatibilized blend compared to the noncompatibilized blend. By this technique, the tensile strength, elongation at break, modulus, tear strength, compression set and hardness of the blend were found to be either at par with or better than that of virgin silica filled NR compound. It is also noted that the thermal properties of the blends are equivalent with that of virgin NR. The study establishes the potential of this method for utilising waste EPS

Utilization of steelmaking waste materials for production of calcium carbonate (CaCO3)

The steel industry produces, besides steel, also solid mineral by-products or slags, while it emits large quantities of carbon dioxide (CO2). Slags consist of various silicates and oxides which are formed in chemical reactions between the iron ore and the fluxing agents during the high temperature processing at the steel plant. Currently, these materials are recycled in the ironmaking processes, used as aggregates in construction, or landfilled as waste. The utilization rate of the steel slags can be increased by selectively extracting components from the mineral matrix. As an example, aqueous solutions of ammonium salts such as ammonium acetate, chloride and nitrate extract calcium quite selectively already at ambient temperature and pressure conditions. After the residual solids have been separated from the solution, calcium carbonate can be precipitated by feeding a CO2 flow through the solution. Precipitated calcium carbonate (PCC) is used in different applications as a filler material. Its largest consumer is the papermaking industry, which utilizes PCC because it enhances the optical properties of paper at a relatively low cost. Traditionally, PCC is manufactured from limestone, which is first calcined to calcium oxide, then slaked with water to calcium hydroxide and finally carbonated to PCC. This process emits large amounts of CO2, mainly because of the energy-intensive calcination step. This thesis presents research work on the scale-up of the above-mentioned ammonium salt based calcium extraction and carbonation method, named Slag2PCC. Extending the scope of the earlier studies, it is now shown that the parameters which mainly affect the calcium utilization efficiency are the solid-to-liquid ratio of steel slag and the ammonium salt solvent solution during extraction, the mean diameter of the slag particles, and the slag composition, especially the fractions of total calcium, silicon, vanadium and iron as well as the fraction of free calcium oxide. Regarding extraction kinetics, slag particle size, solid-to-liquid ratio and molar concentration of the solvent solution have the largest effect on the reaction rate. Solvent solution concentrations above 1 mol/L NH4Cl cause leaching of other elements besides calcium. Some of these such as iron and manganese result in solution coloring, which can be disadvantageous for the quality of the PCC product. Based on chemical composition analysis of the produced PCC samples, however, the product quality is mainly similar as in commercial products. Increasing the novelty of the work, other important parameters related to assessment of the PCC quality, such as particle size distribution and crystal morphology are studied as well. As in traditional PCC precipitation process, the ratio of calcium and carbonate ions controls the particle shape; a higher value for [Ca2+]/[CO32-] prefers precipitation of calcite polymorph, while vaterite forms when carbon species are present in excess. The third main polymorph, aragonite, is only formed at elevated temperatures, above 40-50 °C. In general, longer precipitation times cause transformation of vaterite to calcite or aragonite, but also result in particle agglomeration. The chemical equilibrium of ammonium and calcium ions and dissolved ammonia controlling the solution pH affects the particle sizes, too. Initial pH of 12-13 during the carbonation favors nonagglomerated particles with a diameter of 1 μm and smaller, while pH values of 9-10 generate more agglomerates of 10-20 μm. As a part of the research work, these findings are implemented in demonstrationscale experimental process setups. For the first time, the Slag2PCC technology is tested in scale of ~70 liters instead of laboratory scale only. Additionally, design of a setup of several hundreds of liters is discussed. For these purposes various process units such as inclined settlers and filters for solids separation, pumps and stirrers for material transfer and mixing as well as gas feeding equipment are dimensioned and developed. Overall emissions reduction of the current industrial processes and good product quality as the main targets, based on the performed partial life cycle assessment (LCA), it is most beneficial to utilize low concentration ammonium salt solutions for the Slag2PCC process. In this manner the post-treatment of the products does not require extensive use of washing and drying equipment, otherwise increasing the CO2 emissions of the process. The low solvent concentration Slag2PCC process causes negative CO2 emissions; thus, it can be seen as a carbon capture and utilization (CCU) method, which actually reduces the anthropogenic CO2 emissions compared to the alternative of not using the technology. Even if the amount of steel slag is too small for any substantial mitigation of global warming, the process can have both financial and environmental significance for individual steel manufacturers as a means to reduce the amounts of emitted CO2 and landfilled steel slag. Alternatively, it is possible to introduce the carbon dioxide directly into the mixture of steel slag and ammonium salt solution. The process would generate a 60-75% pure calcium carbonate mixture, the remaining 25-40% consisting of the residual steel slag. This calcium-rich material could be re-used in ironmaking as a fluxing agent instead of natural limestone. Even though this process option would require less process equipment compared to the Slag2PCC process, it still needs further studies regarding the practical usefulness of the products. Nevertheless, compared to several other CO2 emission reduction methods studied around the world, the within this thesis developed and studied processes have the advantage of existing markets for the produced materials, thus giving also a financial incentive for applying the technology in practice.

Utilization of waste materials to improve asphalt mixtures performance

This study aims to develop an innovative bitumen with large quantities of waste materials to improve asphalt mixtures performance. Different amounts of waste motor oil and waste HDPE were added to a new bitumen. The bitumen modified with 10% of waste motor oil and 5% of HDPE showed promising characteristics (high softening point temperatures and penetration slightly higher than the conventional bitumen). After the selection of the most promising modified bitumen, three asphalt mixtures were produced with different bitumens (namely conventional bitumen, commercial modified bitumen and the selected modified bitumen). Beyond that, this modified bitumen improved some mechanical characteristics of the asphalt mixture where it was used, in comparison to conventional and modified asphalt mixtures.