Search results for "hyötykäyttö"
showing 10 items of 15 documents
Brønsted and Lewis acid catalyzed conversion of pulp industry waste biomass to levulinic acid
2019
Enormous amounts of fiber sludge are generated annually by the pulp industry as a by-product. As a cellulose-rich material, its current usage, mainly as fuel, is inefficient from a material efficiency point of view. This work studied the utilization of fiber sludge from a Finnish and a Swedish pulp mill as a potential feedstock to produce levulinic acid, a valuable platform chemical. The conversion experiments of fiber sludge to levulinic acid were performed in a microwave reactor with a mixture of H2SO4 and Lewis acid as the catalyst. The reaction conditions, which included reaction time and temperature as well as the H2SO4 and Lewis acid concentrations, were studied in detail. The highest…
Rolling or Scrolling? The Effect of Content Type on Habitual Use of Facebook
2020
The paper investigates how content type (i.e., hedonic and utilitarian content) is related to satisfaction, habitual use, use intensity and discontinued use intentions in the context of social media services. The research model was empirically tested using a survey study (n = 142) that was conducted among Facebook users. The results show that hedonic content is a strong predictor of habitual use of and satisfaction with Facebook. In turn, utilitarian content has a positive effect on satisfaction; however, it does not significantly affect habitual use. Additionally, habit affects use intensity more than satisfaction but has no significant effect on discontinued use intention. These results s…
Alkali-Activated Adsorbents from Slags: Column Adsorption and Regeneration Study for Nickel(II) Removal
2021
Alkali-activated adsorbents were synthesized by mixing three different slags from the steel industry: blast furnace slag (BFS), ladle slag (LS), and Lintz–Donawitz converter slag (LD). These powdered slag-based geopolymers (GP) were used to remove nickel(II) from aqueous solutions in fixed-bed column studies. The experiments were conducted in pH 6 using a phosphate buffer with initial nickel(II) concentration of 50 mg/L. Samples were taken at time intervals of between 5 and 90 min. Three adsorption–desorption cycles were implemented with a flow rate of 5 mL/min. The geopolymers were characterized by Fourier-Transform Infrared Spectroscopy (FTIR), X-ray powder diffraction (XRD), Field Emissi…
Ongelmaeläimyyden monet ja muuttuvat määrittelyt
2022
Suomeen 1900-luvun puolivälin paikkeilla levinnyt supikoira (Nyctereutes procyonoides) on herättänyt monenlaista huolta ja keskustelua yhteiskunnan eri tasoilla ja ryhmittymissä. Supikoirakannan vähentämiselle löytyy vähän vastustajia, mutta osalle tämä keskikokoinen nisäkäs näyttää olevan niin iso ongelma, että supikoirapuhe saa paikoin raivokkaita sävyjä. Tarkastelen tässä tutkimuksessa keskustelun ongelmaeläinkäsityksiä kehysanalyysillä. Käytän uusstrukturalistiseen kehikkoon sijoittuvassa tarkastelussa sanomalehtien supikoirakirjoituksia aikaväliltä 1970–2020, jolle sijoittuu myös rakennemuutosten ja ympäristöheräämisen kaltaisia suomalaista yhteiskuntaa ja sen ympäristösuhdetta uudelle…
Yhdyskuntajätevesilietteen alkuainekoostumuksen määrittäminen käyttämällä ICP-OES ja ICP-MS laitteistoja
2017
Kiertotalouden ideana on hyödyntää jäte- ja sivuvirroista saatavat raaka-aineet uusien tuotteiden tuottamiseen, jolloin voidaan säästää neitseellisiä raaka-aineita. Näitä ovat esimerkiksi lannoitteissa käytettävä fosfori ja useissa fossiilisia polttoaineita korvaavissa tuotteissa käytettävät harvinaiset maametallit ja jalometallit. Luonnonsuojelun lisäksi kiertotalouteen kannustavat jatkuvasti kasvava kysyntä resursseista sekä niiden saatavuuden hankaloituminen. Jyväskylän seudulla käynnistetyn Innovatiivinen kiertotalous -hankkeen kiinnostuksen kohteena on Nenäinniemen jätevedenpuhdistamon mädätetyn jätevesilietteen kiertotaloudellisen arvon selvittäminen. Tämän Pro gradu -työn tarkoitukse…
Bromattujen palonestoaineiden rajoitusten vaikutus jätteiden hyödyntämiseen ja käsittelyyn
2012
Tässä tutkimuksessa selvitettiin bromattujen palonestoaineiden määrää eri jätejakeissa. Tutkitut yhdisteet olivat kaupalliset PBDE:t (PeBDE, OBDE ja DBDE) ja HBCD. Näiden yhdisteiden on todettu olevan haitallisia terveydelle ja ympäristölle sekä suoraan että välil-lisesti. PeBDE, OBDE ja HBCD ovat POP-yhdisteitä. Kyseisillä yhdisteillä on pääosin suojattu sähkö- ja elektroniikkalaitteita ja ajoneuvoja. Työ jakaantuu kirjalliseen ja kokeelliseen osioon. Kirjallisessa osiossa tarkasteltiin yhdis-teiden käyttökohteita ja käytön rajoituksia. Kokeellisessa osiossa tehtiin kenttämittauksia ja yhdisteanalyysejä kenttämittausten perusteella valikoiduista näytteistä. Yhdisteanalyysien avulla selvite…
Effect of different co-solvents on biodiesel production from various low-cost feedstocks using Sr–Al double oxides
2020
The main objective of the present paper comprises the investigation of biodiesel production from low-cost feedstock such as lard oil and waste cooking oil (WCO) using Sr-Al double oxides. Nanocatalyst was characterised FTIR, XRD, SEM, TEM, BET and XPS. The Sr:Al with 3:1 molar ratio showed the best catalytic activity in the conversion of both oils to fatty acid methyl ester. The effect of acetone and tetrahydrofuran (THF) as a co-solvent for transesterification were compared and the best result was obtained with 5 % THF. The mutual effect of the nanocatalyst and co-solvent on biodiesel production was investigated. The characterisation of biodiesel synthesised from lard oil and WCO was perfo…
Water-smart circular economy – Conceptualisation, transitional policy instruments and stakeholder perception
2022
Highlights • A concept for a water-smart Circular Economy (CE) is introduced. • Elements of a water-smart CE are presented. • Instruments to support the transition to a water-smart CE are analysed. • Drivers for and barriers to the transition to a water-smart CE are identified. The Circular Economy (CE) is a concept that has gained considerable global attention during the past decade amongst private and public sector actors, politicians and policymakers, citizens and media, and scientific communities. Water and water-related ecosystems, despite their vital role in practically all human activities, have been largely missing from conceptualisations and scientific definitions of the CE. Theref…
The use of calcined paper mill sludge as a chemical precipitant in the simultaneous removal of ammonium and phosphate : paper mill waste recycling an…
2020
Currently, recycling and re-use of materials is extremely important due to the diminishing of natural resources. The objective of the European Union’s circular economy strategy is to increase recycling and the use of industrial waste materials and side streams as secondary raw materials. In this study, a chemical precipitation method to simultaneously remove ammonium nitrogen and phosphate from the liquid phase of anaerobic digestate using calcined paper mill sludge was studied. Papermill sludge is a waste material that forms in the paper-making process. In addition, commercial calcium oxide (CaO) was used as a reference precipitant. The suitability of the formed precipitate’s composition f…
Does level of leisure time physical activity, in a sample of patients with depression, predict health care utilization over a subsequent 5-year perio…
2018
Objectives: The main aim of this study was to investigate the association between leisure time physical activity (LTPA) and health care utilization (HCU) and furthermore, socio-demographic and clinical factors according to LTPA level among depressed patients based on data drawn from the Finnish Depression and Metabolic Syndrome in Adults (FDMSA)-study (2009-2016). Methods: 447 depressed patients aged 35-65 from municipalities within the Central Finland Hospital District participated in this study. Depressive symptoms (DS) were determined with the Beck Depression Inventory (a 10 points) and the psychiatric diagnosis confirmed with a diagnostic interview (M.I.N.I.). Severity of depression was…