Titanium dioxide based nanomaterials for photocatalytic water treatment

Water treatment using photocatalysis has gained extensive attention in recent years. Photocatalysis is promising technology from green chemistry point of view. The most widely studied and used photocatalyst for decomposition of pollutants in water under ultraviolet irradiation is TiO2 because it is not toxic, relatively cheap and highly active in various reactions. Within this thesis unmodified and modified TiO2 materials (powders and thin films) were prepared. Physico-chemical properties of photocatalytic materials were characterized with UV-visible spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectrometry (XPS), inductively coupled plasma optical emission spectroscopy (ICP-OES), ellipsometry, time-of-flight secondary ion mass spectrometry (ToF-SIMS), Raman spectroscopy, goniometry, diffuse reflectance measurements, thermogravimetric analysis (TGA) and nitrogen adsorption/desorption. Photocatalytic activity of prepared samples in aqueous environment was tested using model compounds such as phenol, formic acid and metazachlor. Also purification of real pulp and paper wastewater effluent was studied. Concentration of chosen pollutants was measured with high pressure liquid chromatography (HPLC). Mineralization and oxidation of organic contaminants were monitored with total organic carbon (TOC) and chemical oxygen demand (COD) analysis. Titanium dioxide powders prepared via sol-gel method and doped with dysprosium and praseodymium were photocatalytically active for decomposition of metazachlor. The highest degradation rate of metazachlor was observed when Pr-TiO2 treated at 450ºC (8h) was used. The photocatalytic LED-based treatment of wastewater effluent from plywood mill using commercially available TiO2 was demonstrated to be promising post-treatment method (72% of COD and 60% of TOC was decreased after 60 min of irradiation). The TiO2 coatings prepared by atomic layer deposition technique on aluminium foam were photocatalytically active for degradation of formic and phenol, however suppression of activity was observed. Photocatalytic activity of TiO2/SiO2 films doped with gold bipyramid-like nanoparticles was about two times higher than reference, which was not the case when gold nanospheres were used.

Validation of plant dynamic model by online and laboratory measurements – a tool to predict online COD loads out of production of mechanical printing papers

COD discharges out of processes have increased in line with elevating brightness demands for mechanical pulp and papers. The share of lignin-like substances in COD discharges is on average 75%. In this thesis, a plant dynamic model was created and validated as a means to predict COD loading and discharges out of a mill. The assays were carried out in one paper mill integrate producing mechanical printing papers. The objective in the modeling of plant dynamics was to predict day averages of COD load and discharges out of mills. This means that online data, like 1) the level of large storage towers of pulp and white water 2) pulp dosages, 3) production rates and 4) internal white water flows and discharges were used to create transients into the balances of solids and white water, referred to as “plant dynamics”. A conversion coefficient was verified between TOC and COD. The conversion coefficient was used for predicting the flows from TOC to COD to the waste water treatment plant. The COD load was modeled with similar uncertainty as in reference TOC sampling. The water balance of waste water treatment was validated by the reference concentration of COD. The difference of COD predictions against references was within the same deviation of TOC-predictions. The modeled yield losses and retention values of TOC in pulping and bleaching processes and the modeled fixing of colloidal TOC to solids between the pulping plant and the aeration basin in the waste water treatment plant were similar to references presented in literature. The valid water balances of the waste water treatment plant and the reduction model of lignin-like substances produced a valid prediction of COD discharges out of the mill. A 30% increase in the release of lignin-like substances in the form of production problems was observed in pulping and bleaching processes. The same increase was observed in COD discharges out of waste water treatment. In the prediction of annual COD discharge, it was noticed that the reduction of lignin has a wide deviation from year to year and from one mill to another. This made it difficult to compare the parameters of COD discharges validated in plant dynamic simulation with another mill producing mechanical printing papers. However, a trend of moving from unbleached towards high-brightness TMP in COD discharges was valid.

Chemistry of potassium halides and their role in corrosion in biomass and waste firing

Compared to the use of traditional fossil fuels (coal, oil, natural gas), combustion of biomass and waste fuels has several environmental and economic advantages for heat and power generation. However, biomass and waste fuels might contain halogens (Cl, Br, F), alkali metals (Na, K) and heavy metals (Zn, Pb), which may cause harmful emissions and corrosion problems. Hightemperature corrosion occurs typically on furnace waterwalls and superheaters. The corrosion of the boiler tube materials limits the increase of thermal efficiency of steam boilers and leads to costly shutdowns and repairs. In recent years, some concerns have been raised about halogen (Cl, Br, and F)-related hightemperature corrosion in biomass- and waste-fired boilers. Chlorine-related high-temperature corrosion has been studied extensively. The presence of alkali chlorides in the deposits is believed to play a major role in the corrosion observed in biomass and waste fired boilers. However, there is much less information found in literature on the corrosion effect of bromine and fluorine. According to the literature, bromine is only assumed to play a role similar to chlorine; the role of fluorine is even less understood. In this work, a series of bubbling fluidized bed (BFB) bench-scale tests were carried out to characterize the formation and sulfation behaviors of KCl and KBr in BFB combustion conditions. Furthermore, a series of laboratory tests were carried out to investigate the hightemperature corrosion behaviors of three different superheater steels (10CrMo9-10, AISI 347 and Sanicro 28) exposed to potassium halides in ambient air and wet air (containing 30% H2O). The influence of H2O and O2 on the high-temperature corrosion of steels both with and without a salt (KCl) in three gas atmospheres (2% H2O-30% O2-N2, 2% H2O-2% O2-N2 and 30% H2O-2% O2-N2) was also studied. From the bench-scale BFB combustion tests, it was found that HBr has a clearly higher affinity for the available K forming KBr than HCl forming KCl. The tests also indicated that KCl has a higher tendency for sulfation than KBr. From the laboratory corrosion tests in ambient air (also called “dry air” in Paper III and Paper IV), it was found that at relatively low temperatures (≤ 550 °C) the corrosivity of KBr and KF are similar to KCl. At 600 °C, KF showed much stronger corrosivity than KBr and KCl, especially for 10CrMo9-10 and AISI 347. When exposed to KBr or KF, 10CrMo9-10 was durable at least up to 450 °C, while AISI 347 and Sanicro 28 were durable at least up to 550 °C. From the laboratory corrosion tests in wet air (30% H2O), no obvious effect of water vapor was detected at 450 °C. At 550 °C, the influence of water vapor became significant in some cases, but the trend was not consistent. At 550 °C, after exposure with KBr, 10CrMo9-10 suffered from extreme corrosion; after exposure with KF and KCl, the corrosion was less severe, but still high. At 550 °C, local deep pitting corrosion occurred on AISI 347 and Sanicro 28 after exposure with KF. Some formation of K2CrO4 was observed in the oxide layer. At 550 °C, AISI 347 and Sanicro 28 suffered from low corrosion (oxide layer thickness of < 10 μm) after exposure with KBr and KCl. No formation of K2CrO4 was observed. Internal oxidation occurred in the cases of AISI 347 with KBr and KCl. From the laboratory corrosion tests in three different gas atmospheres (2% H2O-30% O2-N2, 2% H2O-2% O2-N2 and 30% H2O-2% O2-N2), it was found that in tests with no salt, no corrosion occurred on AISI 347 and Sanicro 28 up to 600 °C in both the “O2-rich” (2% H2O-30% O2-N2) and “H2O-rich” (30% H2O-2% O2-N2) gas atmospheres; only 10CrMo9-10 showed increased corrosion with increasing temperature. For 10CrMo9-10 in the “O2-rich” atmosphere, the presence of KCl significantly increased the corrosion compared to the “no salt” cases. For 10CrMo9-10 in the “H2O-rich” atmosphere, the presence or absence of KCl did not show any big influence on corrosion. The formation of K2CrO4 was observed only in the case with the “O2-rich” atmosphere. Considering both the results from the BFB tests and the laboratory corrosion tests, if fuels containing Br were to be combusted, the corrosion damage of superheaters would be expected to be higher than if the fuels contain only Cl. Information generated from these studies can be used to help the boiler manufacturers in selecting materials for the most demanding combustion systems.

Relationship marketing in Latin American context: Implications for small Finnish software companies in Latin American B2B partnerships

After a productivity decrease of established national export industries in Finland such as mobile and paper industries, innovative, smaller companies with the intentions to internationalize right from the start have been proliferating. For software companies early internationalization is an especially good opportunity, as Internet usage becomes increasingly homogeneous across borders and software products often do not need a physical distribution channel. Globalization also makes Finnish companies turn to unfamiliar export markets like Latin America, a very untraditional market for Finns. Relationships consisting of Finnish and Latin American business partners have therefore not been widely studied, especially from a new-age software company’s perspective. To study these partnerships, relationship marketing theory was taken into the core of the study, as its practice focuses mainly on establishing and maintaining relationships with stakeholders at a profit, so that the objectives of all parties are met, which is done by a mutual exchange and fulfillment of promises. The most important dimensions of relationship marketing were identified as trust, commitment and attraction, which were then focused on, as the study aims to understand the implications Latin American business culture has for the understanding, and hence, effective application of relationship marketing in the Latin American market. The question to be answered consecutively was how should the dimensions of trust, commitment and attraction be understood in business relationships in Latin America? The study was conducted by first joining insights given by Latin American business culture literature with overall theories on the three dimensions. Through pattern matching, these insights were compared to empirical evidence collected from business professionals of the Latin American market and from the experiences of Finnish software businesses that had recently expanded into the market. What was found was that previous literature on Latin American business culture had already named many implications for the relationship marketing dimensions that were relevant also for small Finnish software firms on the market. However, key findings also presented important new drivers for the three constructs. Local presence in the area where the Latin American partner is located was found to drive or enhance trust, commitment and attraction. High-frequency follow up procedures were in turn found to drive commitment and attraction. Both local presence and follow up were defined according to the respective evidence in the study. Also, in the context of Finnish software firms in relationships with Latin American partners, the national origins or the foreignness of the Finnish party was seen to enhance trust and attraction in the relationship

Key Account Management in Paper and Board Industry- Identification of Key Accounts for Stora Enso Graphical Boards

Tutkimuksen tarkoituksena oli tunnistaa nykyiset sekä potentiaaliset avainasiakkaat case yritykselle. Avainasiakkaat tunnistettiin Chevertonin tunnistamis- ja valintamatriisin avulla, jossa asiakkaan sijoittumista matriisiin arvioidaan asiakkaan houkuttelevuuden sekä toimittajan suhteellisten vahvuuksien avulla. Kriteereiksi avainasiakkaiden tunnistamiseen valittiin asiakkaan vuotuinen ostovolyymi, asiakkaan business-potentiaali sekä case-yrityksen toimittajaosuus. Asiakkaat luokiteltiin avainasiakkaisiin, kehitettäviin avainasiakkaisiin, ylläpidettäviin asiakkaisiin sekä satunnaisiin asiakkaisiin. Tutkimus tarjosi lähtökohdan case-yrityksen uusille avainasiakaspäälliköille sekä osoitti suunnan tulevaisuuden tutkimustarpeille. Aktiivisen tiedonvaihdannan kautta eri myyntikonttoreiden johtohenkilöstön sekä myös yrityksen eri funktionaalisten divisioonien välillä voidaan saavuttaa kilpailuetua kun lähestytään asiakasta toimintojaan järkiperäisesti koordinoineena toimittajana samalla kun asiakkaat keskittävät ostojaan. Jotta yrityksen tavoitteet, markkinamahdollisuudet sekä resurssit olisivat hyvin tasapainossa, tulisi myös asiakaskannattavuutta sekä asiakkaiden strategista merkittävyyttä arvioida ja mitata säännöllisesti tässä tutkimuksessa käytettyjen tunnistuskriteereiden lisäksi.

Market Potential and Demand Drivers for a Special Laminating Paper: Implementation of Market Research

Tutkimuksen tavoitteena oli selvittää raaka-aineena käytettävän paloa hidastavan laminaattipaperin markkinapotentiaali sekä kysyntä Euroopassa. Näiden kehitystä arvioitiin analysoimalla kysyntään vaikuttavia tekijöitä. Tutkimusmetodologiassa yhdistyivät useat lähestymistavat, pääasiassa käytettiin kuvailevaa ja ennustavaa tutkimusotetta. Tutkimus perustui sekä primaari että sekundaaritietoon. Primaaritietoa hankittiin tuotteen käyttäjiltä, myyntiedustajilta sekä haastattelemalla tuottajayrityksen henkilökuntaa. Sekundaaritietoa kerättiin myös, mutta tutkimuksen tavoitteisiin liittyviä lähteitä ei ollut runsaasti saatavilla. Tästä syystä primaaritiedolla oli tutkimuksessa hieman tärkeämpi rooli kuin sekundaaritiedolla, mikä on yleistä teollisessa markkinatutkimuksessa. Tuotteen tulevaisuuden näkymät vaikuttavat melko hyviltä. Teoreettinen markkinapotentiaali on suuri verrattuna nykyiseen myyntimäärään, myyntimäärän kasvattaminen vaatii kuitenkin tiettyjä toimenpiteitä. Tulevaisuudessa huomiota tulisi kiinnittää tuotekuvaan, hinnoitteluun ja laadun kokonaisvaltaiseen maksimointiin. Tutkimuksessa havaittiin suuntauksia kysynnän kasvusta tulevien parin vuoden aikana. Myös teoreettinen markkinapotentiaali voisi kasvaa, koska paloa hidastavien laminaattien kysyntä vaikuttaa kasvavan Euroopassa erityisesti rakennusalalla.