Wastewater Treatment and Deinking Sludge Utilization Possibilities for Energy and Material Recovery in the Leningrad Region

Operation of pulp and paper mills generates waste including wastewater treatment sludge and deinking sludge. Both sludge types are generated in large amounts and are mainly disposed of in landfills in the Leningrad Region resulting in environmental degradation. The thesis was aimed at seeking new sustainable ways of sludge utilization. Two paper mills operating in the Leningrad Region and landfilling their sludge were identified: “SCA Hygiene Products Russia” and “Knauf”. The former generates 150 t/day of deinking sludge, the latter – 145 t/day of secondary sludge. Chemical analyses of deinking sludge were performed to assess applicability of sludge in construction materials production processes. Higher heating value on dry basis of both sludge types was determined to evaluate energy potential of sludge generated in the Leningrad Region. Total energy output from sludge incineration was calculated. Deinking sludge could be utilized in the production process of “LSR-Cement” or “Slantsy Cement Plant Cesla” factories, and “Pobeda” and “Nikolsky” brick mills without exceeding current sludge management costs.

Teräohjaimet jakopyörösahoissa

Diplomityön tavoitteena oli tutkia pyöröterän kehältä ohjauksen soveltuvuutta kaksiakselisiin jakosahoihin. Tavoitteena oli tuottaa uutta tietoa sahalaitoksen tuotantoprosessin koneiden suunnitteluun sahakonetekniikan edelleen kehittämiseksi. Työ voi myös palvella sahalaitoksia yhtenä työkaluna koneiden valinnassa tuotantoprosessin tehostamiseksi. Diplomityössä on tutkittu tekniikkaa suomalaisen sahakonevalmistajan, Veisto Oy:n näkökulmasta mutta työn tulokset ovat tarkoitettu yleisesti sovellettaviksi. Diplomityön kirjallisuusosa koostuu teräohjainjärjestelmän etujen ja haittojen kartoituksesta puuraaka-aineen käyttösuhteen, käytettävyyden, tuotantonopeuksien, kunnossapidon ja käytön näkökannoilta tarkasteltuna. Lisäksi työhön on liitetty aiheeseen kiinteästi liittyvä kirjallisuuteen ja valmistajilta saatuihin tietoihin perustuva katsaus tämän hetken pyöröterätekniikkaan. Työssä analysoidaan myös kevättalvella 2002 Itä-Kanadassa suoritettujen sahauskokeiden tuloksia. Kokeissa tutkittiin kehältä ohjatuille terille muutetun jakosahayksikön suorituskykyä ja käytettävyyttä. Tutkittava kone oli Veisto Oy:n valmistama muuttuva-asetteinen pelkkahakkuri -VDA -jakosaha, tyypiltään HewSaw R200 MSA SE.

Competence Development and Capacity Building of Sawmill Enterprises in Kenya – A Human Resources Development Approach

The Kenyan forestry and sawmilling industry have been subject to a changing environment since 1999 when the industrial forest plantations were closed down. This has lowered raw material supply and it has affected and reduced the sawmill operations and the viability of the sawmill enterprises. The capacity of the 276 registered sawmills is not sufficient to fulfill sawn timber demand in Kenya. This is because of the technological degradation and lack of a qualified labor force, which were caused because of non-existent sawmilling education and further training in Kenya. Lack of competent sawmill workers has led to low raw material recovery, under utilization of resources and loss of employment. The objective of the work was to suggest models, methods and approaches for the competence and capacity development of the Kenyan sawmilling industry, sawmills and their workers. A nationwide field survey, interviews, questionnaire and literature review was used for data collection to find out the sawmills’ competence development areas and to suggest models and methods for their capacity building. The sampling frame included 22 sawmills that represented 72,5% of all the registered sawmills in Kenya. The results confirmed that the sawmills’ technological level was backwards, productivity low, raw material recovery unacceptable and workers’ professional education low. The future challenges will be how to establish the sawmills’ capacity building and workers’ competence development. Sawmilling industry development requires various actions through new development models and approaches. Activities should be started for technological development and workers’ competence development. This requires re-starting of vocational training in sawmilling and the establishment of more effective co-operation between the sawmills and their stakeholder groups. In competence development the Enterprise Competence Management Model of Nurminen (2007) can be used, whereas the best training model and approach would be a practically oriented learning at work model in which the short courses, technical assistance and extension services would be the key functions.

Pinnoiteteollisuudessa syntyvien maalijätteiden hyötykäyttö ja uudet liiketoimintamahdollisuudet

Tämän diplomityön tavoite on kartoittaa maalien ja lakkojen valmistuksessa syntyvien sivuvirtojen hyötykäyttöä ja hyötykäyttöpotentiaalia nykyisellään. Työn tarkoitus on toimia esiselvityksenä pinnoiteteollisuuden sivuvirtojen hyötykäyttöön liittyvien liiketoimintamahdollisuuksien syvemmälle analyysille. Teollisuuden sivuvirtoihin liittyvää tietoa kerätään tilastoista ja olemassa olevista raporteista sekä haastattelemalla teollisuus- ja palveluyritysten edustajia sekä alan asiantuntijoita. Sivuvirtojen teknisten hyötykäyttömahdollisuuksien ja liiketoiminnallisten mahdollisuuksien tarkastelua varten järjestetään työpajoja asiantuntijoille Apila Group Oy Ab:n asiantuntijaverkostossa. Neljässä haastatellussa tuotantolaitoksissa syntyi vuonna 2008 yhteensä 6 662 tonnia kiinteää jätettä ja lietteitä. 68 % näistä sivuvirroista hyötykäytettiin energiana tai polttoaineen valmistuksessa. Materiaalina sivuvirtoja hyötykäytettiin 16 % sivuvirroista, pääasiassa pahvia, paperia, metalleja sekä tynnyreitä ja kontteja. Myös merkittävä osa liuottimista otettiin talteen uudelleenhyödyntämistä varten. Tässä diplomityössä hyötykäyttömahdollisuuksien tarkempaa tarkastelua varten valittiin tavanomaisiksi jätteiksi luokiteltuja maalisivuvirtoja, joita haastatelluissa tuotantolaitoksissa syntyi noin 1 500 tonnia. Maalisivuvirtojen tärkeimmät materiaaliominaisuudet liittyvät niiden sisältämiin täyte- ja sideaineisiin, jotka muodostavat merkittävän osan maalien koostumuksesta. Selvityksen mukaan nämä ominaisuudet voidaan ottaa hyötykäyttöön erilaisissa yhdistelmämateriaaleissa, esimerkiksi ekstruusiopuristetuissa tai ahtopuristetuissa muovikuitukomposiiteissa. Komposiittien raaka-aineena käytetään jo erilaisia sivuvirtoja ja lisäksi erilaisten komposiittien markkinoiden ennustetaan kasvavan. Tämä voi tarjota mahdollisuuksia uusille palvelu-, t&k- tai tuotteistusliiketoiminnoille. Kuivilla maalijätteillä on myös hyvä lämpöarvo, jolloin energiahyötykäytön ja palamisjäännöksen materiaalihyötykäytön yhdistäminen mm. keramiikka- tai sementtiteollisuudessa voi tarjota mahdollisuuksia uusille liiketoiminnoille.

Kierrätyspolttoainemarkkinat Euroopassa

Työn tavoitteena oli selvittää Saksan, Ruotsin ja Suomen kierrätyspolttoaineen valmistusta ja käyttöä sekä kierrätyspolttoainemarkkinoita. Kierrätyspolttoaineiden käyttöä ja valmistusta sekä kierrätyspolttoainemarkkinoita säädellään tarkastelumaissa EU-lainsäädännöllä ja kansallisilla lainsäädännöillä jätteistä, jätteenpoltosta ja materiaalikierrätyksestä sekä CEN/TC 343-toimikunnan standardeilla kiinteille kierrätyspolttoaineille. Työn johtopäätöksenä on, että kierrätyspolttoainemarkkinat ovat tarkastelumaissa hyvin ulkoapäin ohjautuvat ja markkinaehtoista tasapainoa ei ehdi syntyä. Tarkastelumaiden markkinat ovat erilaiset, Saksassa kierrätyspolttoaineiden käyttö ja valmistus on pitkälle kehittynyttä, tiheää ja monipuolista, Ruotsissa yhteisen termistön puuttuminen kertoo alan hajanaisuudesta. Saksassa ja Ruotsissa kierrätyspolttoainemarkkinoiden kasvamiseen ovat vaikuttaneet kaatopaikkakiellot. Suomessa tähän asti pelkkään rinnakkaispolttoon perustuneet kierrätyspolttoainemarkkinat ovat vasta vakiintumassa. Kierrätyspolttoainemarkkinat tulevat kansainvälistymään ja kilpailu materiaalista tulee kovenemaan. Standardien käyttöönotto tulee olemaan helpointa Suomessa, jossa kierrätyspolttoaineen standardisoinnista on kokemusta. Suomen olisi syytä ottaa jäte- ja energiahuollon ratkaisuissa huomioon eri toimintojen aiheuttamat talous- ja ympäristövaikutukset.

Toimintaohjeistus HSY:n jätteenpolton materiaalivirtojen hallintaan

Vantaan Energia rakentaa ympäristövaatimukset täyttävän jätevoimalan Itä-Vantaan Långmossebergeniin. Jätevoimalassa tullaan käyttämään polttoaineena kierrätykseen kelpaamatonta syntypaikkalajiteltua yhdyskuntajätettä sekä maakaasua. Helsingin seudun ympäristöpalvelut -kuntayhtymä HSY tulee toimittamaan noin 80 % vuosittaisesta jätepolttoaineesta. Tässä työssä on esitetty toimintamalli HSY:n jätteenpolton materiaalivirtojen hallitsemiseksi. Toimintamallin tarkoituksena on antaa ohjeistus jätteiden materiaalivirtojen käsittelymenetelmistä ennen jätteenpolttolaitosta. Lisäksi toimintamallin tarkoituksena on saada vähennettyä pohjakuonan määrää. Toimintamalli sisältää ohjeistuksen kotitalouksien sekajätteen, pienjäteasemien sekajätteen, sekalaisen rakennus- ja purkujätteen sekä kaupan- ja teollisuuden jätteiden käsittelytavoista. Jätevirtojen koostumusta on selvitetty kirjallisuudesta löytyvien tietojen perusteella ja tietoja on täydennetty kesällä 2013 suoritetun lajittelututkimuksen tiedoilla. Tutkimuksen tuloksista selvisi, että pienjäteasemien sekajätteiden lajittelua tehostamalla HSY:llä pystytään tekemään merkittäviä taloudellisia säästöjä. Tutkimuksessa selvisi, että kipsilevy olisi kannattavinta kerätä omalle lavalleen pienjäteasemilla. Sekalaisen rakennus- ja purkujätteen osalta todettiin, että sitä ei kannata ohjata suoraan jätevoimalalle poltettavaksi, eikä sitä voida sijoittaa käsittelemättömänä kaatopaikalle vuoden 2020 jälkeen. Tästä syystä työssä on ehdotettu, että sekalainen rakennus- ja purkujäte ohjattaisiin lajittelulaitokselle käsiteltäväksi ennen sen loppusijoittamista. Tutkimuksen tulosten perusteella voidaan myös todeta, että toimintamallia noudattamalla, pohjakuonan määrää on mahdollista vähentää lähes puolella alkuperäisestä arviosta.

Deinking sludge utilization possibilities: technical, economic, and environmental assessments

This report introduces the ENPI project called “EMIR - Exploitation of Municipal and Industrial Residues” which was executed in a co-operation between Lappeenranta University of Technology (LUT), Saint Petersburg State University of Economics (SPbSUE), Saint Petersburg State Technical University of Plant Polymers (SPbSTUPP) and industrial partners from both Leningrad Region (LR), Russia and Finland. The main targets of the research were to identify the possibilities for deinking sludge management scenarios in co-operation with partner companies, to compare the sustainability of the alternatives, and to provide recommendations for the companies in the Leningrad Region on how to best manage deinking sludge. During the literature review, 24 deinking sludge utilization possibilities were identified, the majority falling under material recovery. Furthermore, 11 potential utilizers of deinking sludge were found within the search area determined by the transportation cost. Each potential utilizer was directly contacted in order to establish cooperation for deinking sludge utilization. Finally, four companies, namely, “Finnsementti” – a cement plant in Finland (S1), “St.Gobian Weber” – a light-weight aggregate plant in Finland (S2), “LSR-Cement” – a cement plant in LR (S3), and “Rockwool” – a stone wool plant in LR (S4) were seen as the most promising partners and were included in the economic and environmental assessments. Economic assessment using cost-benefit analysis (CBA) indicated that substitution of heavy fuel oil with dry deinking sludge in S2 was the most feasible option with a benefit/cost ratio (BCR) of 3.6 when all the sludge was utilized. At the same time, the use of 15% of the total sludge amount (the amount that could potentially be treated in the scenario) resulted in a BCR of only 0.16. The use of dry deinking sludge in the production of cement (S3) is a slightly more feasible option with a BCR of 1.1. The use of sludge in stone wool production is feasible only when all the deinking sludge is used and burned in an existing incineration plant. The least economically feasible utilization possibility is the use of sludge in cement production in Finland (S1) due to the high gate fee charged. Environmental assessment was performed applying internationally recognized life cycle assessment (LCA) methodologies: ISO 14040 and ISO 14044. The results of a consequential LCA stated that only S1 and S2 lead to a reduction of all environmental impacts within the impact categories chosen compared to the baseline scenario where deinking sludge is landfilled. Considering S1, the largest reduction of 13% was achieved for the global warming potential (GWP), whereas for S2, the largest decrease of abiotic depletion potential (ADP) was by 1.7%, the eutrophication potential (EP) by 1.8%, and a GWP of 2.1% was documented. In S3, the most notable increase of ADP and acidification potential (AP) by 2.6 and 1.5% was indicated, while the GWP was reduced by 12%, the largest out of all the impact categories. In S4, ADP and AP increased by 2.3 and 2.1% respectively, whereas ODP was reduced by 25%. During LCA, it was noticed that substitution of fuels causes a greater reduction of environmental impact (S1 and S2) than substitution of raw materials (S3 and S4). Despite a number of economically and environmentally acceptable deinking sludge utilization methods being assessed in the research, evaluation of bottlenecks and communications with companies’ representatives uncovered the fact that the availability of the raw materials consumed, and the risks associated with technological problems resulting from the sludge utilization, limited the willingness of industrial partners to start deinking sludge utilization. The research results are of high value for decision-makers at already existing paper mills since the result provide insights regarding alternatives to the deinking sludge utilization possibilities already applied. Thus, the research results support the maximum economic and environmental value recovery from waste paper utilization.

Recovery of organic acids with liquid-liquid extraction contactors

Liquid-liquid extraction is a mass transfer process for recovering the desired components from the liquid streams by contacting it to non-soluble liquid solvent. Literature part of this thesis deals with theory of the liquid-liquid extraction and the main steps of the extraction process design. The experimental part of this thesis investigates the extraction of organic acids from aqueous solution. The aim was to find the optimal solvent for recovering the organic acids from aqueous solutions. The other objective was to test the selected solvent in pilot scale with packed column and compare the effectiveness of the structured and the random packing, the effect of dispersed phase selection and the effect of packing material wettability properties. Experiments showed that selected solvent works well with dilute organic acid solutions. The random packing proved to be more efficient than the structured packing due to higher hold-up of the dispersed phase. Dispersing the phase that is present in larger volume proved to more efficient. With the random packing the material that was wetted by the dispersed phase was more efficient due to higher hold-up of the dispersed phase. According the literature, the behavior is usually opposite.

Recovery and refining of manganese as by-product from hydrometallurgical processes

The consumption of manganese is increasing, but huge amounts of manganese still end up in waste in hydrometallurgical processes. The recovery of manganese from multi-metal solutions at low concentrations may not be economical. In addition, poor iron control typically prevents the production of high purity manganese. Separation of iron from manganese can be done with chemical precipitation or solvent extraction methods. Combined carbonate precipitation with air oxidation is a feasible method to separate iron and manganese due to the fast kinetics, good controllability and economical reagents. In addition the leaching of manganese carbonate is easier and less acid consuming than that of hydroxide or sulfide precipitates. Selective iron removal with great efficiency from MnSO4 solution is achieved by combined oxygen or air oxidation and CaCO3 precipitation at pH > 5.8 and at a redox potential of > 200 mV. In order to avoid gypsum formation, soda ash should be used instead of limestone. In such case, however, extra attention needs to be paid on the reagents mole ratios in order to avoid manganese coprecipitation. After iron removal, pure MnSO4 solution was obtained by solvent extraction using organophosphorus reagents, di-(2-ethylhexyl)phosphoric acid (D2EHPA) and bis(2,4,4- trimethylpentyl)phosphinic acid (CYANEX 272). The Mn/Ca and Mn/Mg selectivities can be increased by decreasing the temperature from the commonly used temperatures (40 –60oC) to 5oC. The extraction order of D2EHPA (Ca before Mn) at low temperature remains unchanged but the lowering of temperature causes an increase in viscosity and slower phase separation. Of these regents, CYANEX 272 is selective for Mn over Ca and, therefore, it would be the better choice if there is Ca present in solution. A three-stage Mn extraction followed by a two-stage scrubbing and two-stage sulfuric acid stripping is an effective method of producing a very pure MnSO4 intermediate solution for further processing. From the intermediate MnSO4 some special Mn- products for ion exchange applications were synthesized and studied. Three types of octahedrally coordinated manganese oxide materials as an alternative final product for manganese were chosen for synthesis: layer structured Nabirnessite, tunnel structured Mg-todorokite and K-kryptomelane. As an alternative source of pure MnSO4 intermediate, kryptomelane was synthesized by using a synthetic hydrometallurgical tailings. The results show that the studied OMS materials adsorb selectively Cu, Ni, Cd and K in the presence of Ca and Mg. It was also found that the exchange rates were reasonably high due to the small particle dimensions. Materials are stable in the studied conditions and their maximum Cu uptake capacity was 1.3 mmol/g. Competitive uptake of metals and acid was studied using equilibrium, batch kinetic and fixed-bed measurements. The experimental data was correlated with a dynamic model, which also accounts for the dissolution of the framework manganese. Manganese oxide micro-crystals were also bound onto silica to prepare a composite material having a particle size large enough to be used in column separation experiments. The MnOx/SiO2 ratio was found to affect significantly the properties of the composite. The higher the ratio, the lower is the specific surface area, the pore volume and the pore size. On the other hand, higher amount of silica binder gives composites better mechanical properties. Birnesite and todorokite can be aggregated successfully with colloidal silica at pH 4 and with MnO2/SiO2 weight ratio of 0.7. The best gelation and drying temperature was 110oC and sufficiently strong composites were obtained by additional heat-treatment at 250oC for 2 h. The results show that silica–supported MnO2 materials can be utilized to separate copper from nickel and cadmium. The behavior of the composites can be explained reasonably well with the presented model and the parameters estimated from the data of the unsupported oxides. The metal uptake capacities of the prepared materials were quite small. For example, the final copper loading was 0.14 mmol/gMnO2. According to the results the special MnO2 materials are potential for a specific environmental application to uptake harmful metal ions.

Hydrometallurgical recovery of valuable metals from secondary raw materials

Wastes and side streams in the mining industry and different anthropogenic wastes often contain valuable metals in such concentrations their recovery may be economically viable. These raw materials are collectively called secondary raw materials. The recovery of metals from these materials is also environmentally favorable, since many of the metals, for example heavy metals, are hazardous to the environment. This has been noticed in legislative bodies, and strict regulations for handling both mining and anthropogenic wastes have been developed, mainly in the last decade. In the mining and metallurgy industry, important secondary raw materials include, for example, steelmaking dusts (recoverable metals e.g. Zn and Mo), zinc plant residues (Ag, Au, Ga, Ge, In) and waste slurry from Bayer process alumina production (Ga, REE, Ti, V). From anthropogenic wastes, waste electrical and electronic equipment (WEEE), among them LCD screens and fluorescent lamps, are clearly the most important from a metals recovery point of view. Metals that are commonly recovered from WEEE include, for example, Ag, Au, Cu, Pd and Pt. In LCD screens indium, and in fluorescent lamps, REEs, are possible target metals. Hydrometallurgical processing routes are highly suitable for the treatment of complex and/or low grade raw materials, as secondary raw materials often are. These solid or liquid raw materials often contain large amounts of base metals, for example. Thus, in order to recover valuable metals, with small concentrations, highly selective separation methods, such as hydrometallurgical routes, are needed. In addition, hydrometallurgical processes are also seen as more environmental friendly, and they have lower energy consumption, when compared to pyrometallurgical processes. In this thesis, solvent extraction and ion exchange are the most important hydrometallurgical separation methods studied. Solvent extraction is a mainstream unit operation in the metallurgical industry for all kinds of metals, but for ion exchange, practical applications are not as widespread. However, ion exchange is known to be particularly suitable for dilute feed solutions and complex separation tasks, which makes it a viable option, especially for processing secondary raw materials. Recovering valuable metals was studied with five different raw materials, which included liquid and solid side streams from metallurgical industries and WEEE. Recovery of high purity (99.7%) In, from LCD screens, was achieved by leaching with H2SO4, extracting In and Sn to D2EHPA, and selectively stripping In to HCl. In was also concentrated in the solvent extraction stage from 44 mg/L to 6.5 g/L. Ge was recovered as a side product from two different base metal process liquors with Nmethylglucamine functional chelating ion exchange resin (IRA-743). Based on equilibrium and dynamic modeling, a mechanism for this moderately complex adsorption process was suggested. Eu and Y were leached with high yields (91 and 83%) by 2 M H2SO4 from a fluorescent lamp precipitate of waste treatment plant. The waste also contained significant amounts of other REEs such as Gd and Tb, but these were not leached with common mineral acids in ambient conditions. Zn was selectively leached over Fe from steelmaking dusts with a controlled acidic leaching method, in which the pH did not go below, but was held close as possible to, 3. Mo was also present in the other studied dust, and was leached with pure water more effectively than with the acidic methods. Good yield and selectivity in the solvent extraction of Zn was achieved by D2EHPA. However, Fe needs to be eliminated in advance, either by the controlled leaching method or, for example, by precipitation. 100% Pure Mo/Cr product was achieved with quaternary ammonium salt (Aliquat 336) directly from the water leachate, without pH adjustment (pH 13.7). A Mo/Cr mixture was also obtained from H2SO4 leachates with hydroxyoxime LIX 84-I and trioctylamine (TOA), but the purities were 70% at most. However with Aliquat 336, again an over 99% pure mixture was obtained. High selectivity for Mo over Cr was not achieved with any of the studied reagents. Ag-NaCl solution was purified from divalent impurity metals by aminomethylphosphonium functional Lewatit TP-260 ion exchange resin. A novel preconditioning method, named controlled partial neutralization, with conjugate bases of weak organic acids, was used to control the pH in the column to avoid capacity losses or precipitations. Counter-current SMB was shown to be a better process configuration than either batch column operation or the cross-current operation conventionally used in the metallurgical industry. The raw materials used in this thesis were also evaluated from an economic point of view, and the precipitate from a waste fluorescent lamp treatment process was clearly shown to be the most promising.

An Update on Inter-Country Differences in Recovery and Utilization of Recycled Paper

The use of recovered paper as raw material in the paper and board industry has increased heavily during recent decades. At the same time, growing environmental awareness has raised the interest in recycling and a more sustainable way of living, at least in high-income countries. This paper combines these topics and explores how economic, demographic and environmental factors have affected the recovery and utilization of recycled paper between 1992 and 2010 in a sample of 70 countries. This study updates and extends the previous research on the topic using panel data and panel data estimation methods. The results confirm the roles of economic determinants but also indicate that concern for the environment impacts the recovery of recycled paper particularly in high-income countries. Moreover, the motives for recycling appear to depend on the income level of a country, which is something that future policies should consider.

Enhancement of ultrafiltration process by pretreatment in recovery of hemicelluloses from wood extracts

Hemicelluloses are potential raw material for several items produced in future wood-based biorefineries. One possible method for recovering hemicelluloses from wood extracts is ultrafiltration (UF). However, low filtration capacities and severe fouling restrict the use of tight UF membranes in the treatment of wood extracts. The lack of suitable commercial membranes creates a need for pretreatment which would decrease fouling and increase the filtration capacity. This thesis focuses on the evaluation of the possibility to improve the filtration capacity and decrease fouling with the pretreatment of wood extracts. Methods which remove harmful compounds and methods which degrade them are studied, as well as combinations of the methods. The tested pretreatments have an influence on both the concentration of different compounds and the molecular mass distribution of the compounds in the extract. This study revealed that in addition to which kind of compounds were removed, also the change in molecular size distribution affected the filtration capacity significantly. It was shown that the most harmful compounds for the filtration capacity of the hydrophobic 5 kDa membrane were the ones capable of permeating the membrane and fouling also the inner membrane structure. Naturally, the size of the most harmful compounds depends on the used UF membrane and is thus case-specific. However, in the choice of the pretreatment method, the focus should be on the removal of harmful compound sizes rather than merely on the total amount of removed foulants. The results proved that filtration capacity can be increased with both adsorptive and oxidative pretreatments even by hundreds of per cents. For instance, the use of XAD7 and XAD16 adsorbents increased the average flux in the UF of a birch extract from nearly zero to 107 kg/(m2h) and 175 kg/(m2h), respectively. In the treatment of a spruce extract, oxidation by pulsed corona discharge (PCD) increased the flux in UF from 46 kg/(m2h) to 158 kg/(m2h). Moreover, when a birch extract batch was treated with laccase enzyme, the flux in UF increased from 15 kg/(m2h) to 36 kg/(m2h). However, fouling was decreased only by adsorptive pretreatment while oxidative methods had a negligible or even negative impact on it. This demonstrates that filtration capacity and fouling are affected by different compounds and mechanisms. The results of this thesis show that filtration capacity can be improved and fouling decreased through appropriate pretreatment. However, the choice of the best possible pretreatment is case-specific and depends on the wood extract and the membrane used. Finding the best option requires information on the extract content and membrane characteristics as well as on the filtration performance of the membrane in the prevailing conditions and a multivariate approach. On the basis of this study, it can be roughly concluded that adsorptive pretreatment improves the filtration capacity and decreases fouling rather reliably, but it may lead to significant hemicellulose losses. Oxidation reduces the loss of valuable hemicelluloses and could improve the filtration capacity, but fouling challenges may remain. Combining oxidation with adsorptive pretreatment was not a solution for avoiding hemicellulose losses in the tested cases.