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When discharged into the environment, acidic mining effluents containing sulfate and metals cause the acidification of natural waters and harm to aquatic organisms. Environmental permit conditions are being tightened to prevent pollution, reduce emissions and waste, protect biodiversity, and to promote sustainable use of natural resources. Thus, more sustainable and effective water treatment solutions are required. Biological sulfate reduction can be exploited for the removal of sulfate and the precipitation of many metals as sulfides. In this thesis, a biological treatment process was developed for cold mining-impacted waters (MIWs) using sulfate-reducing bacteria (SRB). The SRB consortium was enriched from a sediment sample collected from a boreal area and acclimatized to cold conditions. Succinate was used as the carbon source for the bacteria. The ability of the SRB consortium to utilize different low-cost carbon sources — conditioned sewage sludge, peat, and whey — was also studied. The consortium was used for the removal of sulfate and metals from synthetic and actual acidic MIWs in a continuous up-flow biofilm reactor. In addition, the SRB consortium and a pure SRB culture isolated from it were both tested for the bioregeneration of sulfate-laden anion exchange resin. The resin was separately loaded with sulfate and incubated with the SRB cultures, when the resin-attached sulfate ions were replaced with the ions present in the SRB solutions. The cold-tolerant SRB consortium was found to grow at temperatures as low as 6 °C. The bacteria were able to utilize low-cost organic carbon sources, and promising results were achieved in the removal of sulfate from synthetic MIW, especially with conditioned sewage sludge as the carbon source. When the sulfidogenic bioreactor was operated at a temperature of 11.7 °C for the treatment of actual MIW, the sulfate reduction rate reached 4500 mg L-1 d-1 and 87% of the initial sulfate content was reduced. Most of the, Tiivistelmä Kaivostoiminnassa muodostuvat happamat metalli- ja sulfaattipitoiset jätevesipäästöt aiheuttavat luonnonvesien happamoitumista ja vahingoittavat vesistöjen eliöitä. Ympäristölupamääräyksiä tiukennetaan ympäristön pilaantumisen ehkäisemiseksi, päästöjen ja jätteiden määrän vähentämiseksi, luonnon monimuotoisuuden suojelemiseksi ja luonnonvarojen kestävän hyödyntämisen edistämiseksi, minkä myötä tarvitaan kestävämpiä ja tehokkaampia vedenkäsittelyratkaisuja. Biologista sulfaatinpelkistystä voidaan hyödyntää sulfaatinpoistoon sekä useiden metallien saostamiseen sulfideina. Tässä väitöstyössä kehitettiin sulfaatinpelkistäjäbakteereja hyödyntävää biologista käsittelyprosessia kylmille kaivosvesille. Sulfaattia pelkistävä bakteerikasvusto rikastettiin pohjoiselta alueelta kerätystä maaperänäytteestä ja totutettiin kylmiin olosuhteisiin. Hiilenlähteenä bakteereille käytettiin sukkinaattia. Lisäksi tutkittiin sulfaattia pelkistävän bakteerikasvuston kykyä käyttää erilaisia edullisia hiilenlähteitä — käsiteltyä yhdyskuntalietettä, turvetta sekä heraa. Sulfaatinpelkistäjäsekakasvustoa hyödynnettiin jatkuvatoimisessa ylösvirtausbiofilmireaktorissa sulfaatin ja metallien poistoon keinotekoisista ja aidoista happamista kaivosvesistä. Sekakasvustoa sekä siitä eristettyä puhdaskasvustoa testattiin myös sulfaattikylläisen anioninvaihtohartsin bioregenerointiin. Hartsi kyllästettiin erikseen sulfaatilla ja kylläistä hartsia inkuboitiin sulfaatinpelkistäjien kanssa, jolloin hartsiin kiinnittyneet sulfaatti-ionit vaihtuivat bakteeriliuosten sisältämiin ioneihin. Kylmänsietokykyisen sulfaatinpelkistäjäkasvuston todettiin kasvavan jopa 6 °C:ssa. Bakteerit pystyivät hyödyntämään edullisia orgaanisia hiilenlähteitä ja etenkin käsitellyn yhdyskuntalietteen käytöllä saavutettiin lupaavia tuloksia sulfaatinpoistossa keinotekoisesta kaivosvedestä. Kun sulfidogeenistä bioreaktoria ajettiin lämpötilassa 11,7 °C, sulfaatinpelkistysnopeus oli parhaimmillaan 4 500 mg L-1 d-1 ja 87 % ai

European Union bioeconomy policy emphasizes that the production of renewable transportation fuels should replace fossil fuels as much as possible. In particular, the utilization of waste or side-stream lignocellulosic materials for fuel production is highly recommended. Moreover, future crises forcing a reliance on locally available sources for fuels and energy may become increasingly common. Barley straw, a common agricultural residue in northern Europe, is a potential raw material for bioalcohol production via fermentation. In this study, the technoeconomic and environmental sustainability of bioethanol and biobutanol production from barley straw were evaluated. When compared with fossil gasoline production and use, the greenhouse gas emissions reduction 77.6% and 72.1% were achieved for ethanol and butanol production, respectively. Thus, the emission reduction of 65% for biofuels demanded by the European Union renewable energy directive was achieved in both biofuel production processes evaluated. However, our results indicated that ethanol production from barley straw, a well-known and mature technology, was an economically feasible process (NPV positive, IRR 20%) but that butanol production with Clostridium species through acetone-butanol-ethanol fermentation has still technoeconomic challenges to overcome (NPV negative, IRR below 10%). This was mainly due to the low yield and high recovery costs of butanol.

Ion exchange technology removes ionic compounds from waters effectively but treatment of the spent regenerant is expensive. The bioregeneration of sulfate-laden strong base anion exchange resin was successfully tested using both pure and mixed sulfate-reducing bacterial cultures. The resin was first used for removal of sulfate from neutral (pH 6.7 ± 0.5) synthetic sodium sulfate solutions, after which the spent resin was regenerated by incubating with a viable sulfate-reducing bacterial culture in batch and column modes. In the batch bioregeneration tests, the achieved bioregeneration was 36–95% of the original capacity of the fresh resin (112 mg SO₄ 2−/g) and it increased with regeneration time (1–14 days). The capacity achieved in the column tests during 24 hours of bioregeneration was 107 mg SO₄ 2−/g after the first regeneration cycle. During the bioregeneration, sulfate was mainly reduced by the sulfate-reducing bacteria (approx. 60%), but part of it was only detached from the resins (approx. 30%). The resin-attached sulfate was most likely replaced with ions present in the liquid sulfate-reducing bacterial culture (e.g., HCO₃−, HS−, and Cl−). During the subsequent exhaustion cycles with the bioregenerated resin, the pH of the treated sodium sulfate solution increased from the original 6.7 ± 0.5 to around 9. The study showed that biological sulfate reduction could be used for sulfate removal in combination with ion exchange, and that the exhausted ion exchange resins could be regenerated using a liquid sulfate-reducing bacterial culture without producing any brine.

The current work focuses on studying the aqueous phase reforming (APR) of pine and birch hydrolysate obtained from waste wood by using organic acids available from biorefineries. Processing of representative synthetic mixtures was utilized in the work in order to support data interpretation related to the influence of different chemical compound and processing parameters on the APR of the actual hydrolysates. It was shown, that hydrogenation of the hydrolysates prior to APR was not feasible in the presence of formic acid, which ruled out one potential processing route. However, it was successfully demonstrated that birch and pine hydrolysates could be directly processed obtaining close to full conversion. The best results were obtained with tailored bimetallic Pd-Pt/sibunit catalyst in a trickle bed reactor system in the temperature range 175 °C–225 °C.

Vanadium is an important and strategic metal that has been widely used in many technological fields. Its consumption has significantly increased during recent decades. Therefore, primary resources are considered insufficient to satisfy demand and many countries are looking for alternative resources for vanadium production. At the same time, the over-limit discharge of vanadium into water systems has raised concerns. This work deals with vanadium removal and recovery from liquid waste streams. In the current study, novel sorbents were developed for vanadium removal from water and evaluated for vanadium sorption from mining-influenced water using different iron-based products in both batch and column mode. A pilot-scale field study was conducted at a closed mine site to remove vanadium from mining-influenced water using ferric oxyhydroxide sorbent (CFH-12). The possibility of recovering vanadium from used CFH-12 was investigated by a two-step process including desorption and precipitation. The developed novel sorbents, iron-modified peat and quaternized pine bark, effectively removed vanadium from synthetic solutions. The maximum vanadium sorption capacity of iron-modified peat and quaternized pine bark was 16.3 mg/g and 34.3 mg/g (pH 4), respectively. The kinetics of the sorption followed the Elovich model for both products, indicating the chemisorption mechanism. In the case of mining-influenced water, the lab-scale results revealed that vanadium can be efficiently removed by iron sorbents. The Elovich model provided a good fit to the batch sorption data and the vanadium sorption process was significantly controlled by both film and intra-particle diffusion. The Thomas and Yoon-Nelson column models were found to fit the experimental data from the packed columns fairly well. The pilot study at the mine site confirmed that filter systems placed in different streams were capable of capturing vanadium from the vanadium-polluted streams. More importantly, vanadi, Tiivistelmä Vanadiini on tärkeä metalli, jota on käytetty laajasti monilla tekniikan aloilla. Vanadiinin kulutus on lisääntynyt merkittävästi viime vuosikymmeninä. Tästä syystä primääriraaka-aineita on pidetty riittämättöminä vastaamaan vanadiinin kysyntää ja monet maat etsivät vaihtoehtoisia lähteitä vanadiinin tuotantoon. Toisaalta vanadiinin joutuminen vesistöihin on herättänyt huolta. Tämän työn tavoitteena on vanadiinin poisto ja talteenotto jätevesistä. Tässä tutkimuksessa kehitettiin uusia sorbentteja vanadiinin poistamiseen vedestä ja arvioitiin vanadiinin sorption tehokkuutta kaivosvedestä käyttämällä erilaisia rautapohjaisia tuotteita sekä panos- että kolonnisysteemissä. Laboratoriokokeiden jälkeen suljetulla kaivosalueella suoritettiin pilot-mittakaavan kenttätutkimus vanadiinin poistamiseksi kaivosvedestä käyttämällä ferrioksihydroksidisorbenttia (CFH-12). Vanadiinin talteenottoa käytetystä CFH-12:sta tutkittiin kaksivaiheisella prosessilla, joka sisältää desorption ja saostuksen. Kehitetyt uudet sorbentit, rautamodifioitu turve ja orgaanisella yhdisteellä modifioitu männyn kuori, poistivat tehokkaasti vanadiinia synteettisistä liuoksista. Rautamodifioidun turpeen ja modifioidun männyn kuoren maksimisorptiokyvyt vanadiinille olivat 16.3 mg/g ja 34.3 mg/g (pH 4). Sorption kinetiikka noudatti molemmilla tuotteilla Elovichin mallia, joka viittaa kemisorptiomekanismiin. Kaivosveden laboratoriomittakaavan kokeissa saatiin selville, että vanadiini voidaan poistaa tehokkaasti rautasorbenteilla. Kolonnikokeiden data noudatti melko hyvin Thomasin ja Yoon-Nelsonin malleja. Pilot-kokeet vahvistivat, että eri virtoihin sijoitetut suodatinjärjestelmät pystyivät poistamaan vanadiinia kaivosvedestä tehokkaasti. Lisäksi pilot-tutkimuksesta kerätystä käytetystä sorbentista (CFH-12) saatiin onnistuneesti talteen vanadiini, joka tarjoaa arvokasta tietoa vanadiinituotannon vaihtoehtoisista raaka-ainelähteistä.

The aim of this study was to develop a biological method for the simultaneous removal of sulfate and metals from acidic low-temperature mining effluents. A mixed consortium of cold-tolerant sulfate-reducing bacteria (SRB) and other microorganisms was immobilized on glass beads and exploited in an up-flow biofilm reactor for the continuous treatment of actual and synthetic mining-impacted waters (MIWs) with initial sulfate concentrations between 1580 and 5350 mg L⁻¹. The proton acidity of the mine waters was neutralized by microbial sulfidogenesis. Metals present in the MIWs were precipitated either off-line or in-line, inside the reactor vessel. High sulfate reduction rates (SRRs), from 1000 to 4500 mg L⁻¹ d⁻¹ at a temperature of 11.7 ± 0.2 °C, were achieved (sulfate removal 43–87%). The bacterial consortium was found to be robust and resistant to changes in growth conditions during the bioreactor experiment. The relative abundance of SRB and the SRR increased at higher sulfate concentrations. Sulfidogenic bioreactors have the potential for treatment of acid mine drainage even at low temperature. It was demonstrated that neutral reactor conditions and high SRRs were maintained when acidic influent was fed into the reactor.

Aminated peat (termed PG-Peat) produced using polyethylenimine and glycidyltrimethylammonium chloride was used for the removal of sulphate from real acid mine drainage (AMD) in batch and column mode sorption studies. In the batch tests, the highest sulphate removal capacity achieved was 125.7 mg/g. PG-Peat was efficient and rapid in sulphate removal from AMD even at low temperatures (2–5 °C), achieving equilibrium within a contact time of 30 min. The PG-Peat column treating real AMD showed even higher sulphate uptake capacity (154.2 mg SO₄²⁻/g) than the batch sorption studies. The regenerative and practical applicability of PG-Peat was also tested in column set-ups using synthetic sulphate solutions (at pH 5.8 and pH 2.0). The sulphate uptake capacity obtained was higher in column mode when the solutions were treated at acidic pH (2.0) compared to pH 5.8. This could be attributed to the presence of cationized amine groups on PG-Peat under acidic pH conditions. Almost complete sulphate desorption was achieved with NaCl in the column that treated synthetic sulphate solution at pH 5.8, while the lowest desorption rates were observed in the column that treated acidic synthetic sulphate solution (pH 2).

The main goal of this study was to develop a cost-efficient biological method for the removal of sulfate from mining effluents in cold conditions. A consortium of cold-tolerant sulfate-reducing bacteria (SRB) was tested at 6 °C regarding the utilization of economically viable, low-cost carbon sources, i.e., whey, conditioned sewage sludge, and peat, in the removal of sulfate from synthetic mining water. Succinate was used as a reference carbon source. Of all the studied low-cost carbon sources, conditioned sewage sludge proved to be the most efficient. Nuclear magnetic resonance (NMR) spectroscopy revealed that sewage sludge contained propionic acid, which proved to be utilizable by SRB under cold conditions. Peat both adsorbed the sulfate and acted as a nutrient source in the sulfate reduction process. When whey was used as a carbon source, only a slight decrease in sulfate concentration was detected. Succinate was found to work in a truly predictable and efficient way as a carbon source in biological sulfate reduction, even at the lowest concentration tested. The use of conditioned sewage sludge increased the bacterial diversity in liquid cultivations significantly. However, the number of SRB was highest in the succinate cultivations.

In this study, two-step surface modification of sawdust using triethanolamine (at 180 °C) and iodomethane (at 42 °C) was performed to produce a novel quaternized biosorbent, TEA-I-SD. The characterization studies revealed significant morphological changes in the sawdust and successful quaternization with a nitrogen content of 5.75%. The highest vanadium removal (96.2%) was achieved at pH 4 (dosage 1 g/L, initial vanadium concentration 19.1 mg/L). Equilibrium was achieved within 8 h of contact time and the adsorption kinetics were well fitted with the pseudo-second-order model. Both film diffusion and intra-particle diffusion contributed to the adsorption process, while the latter was the rate-limiting step. The maximum vanadium adsorption capacity of TEA-I-SD (35.0 mg/g, pH 4) was close to the theoretical value obtained from the Langmuir model. The best fit was achieved with the Redlich-Peterson model, exhibiting a monolayer adsorption phenomenon. Tests with real mine water containing 11 mg/L of vanadium also confirmed its high removal (91.3%, dosage 1 g/L) using TEA-I-SD at pH 4. The TEA-I-SD could be reused three times without significant capacity loss after regeneration, although the desorption efficiency was rather low (synthetic solution: 38.5–40.5% and mine water: 26.2–43.1%).

In this study, four ternary liquid-liquid equilibrium systems containing a solvent, furfural, and water were investigated by performing liquid-liquid equilibrium measurements at two different temperatures. The solvents were n-pentyl acetate, n-hexyl acetate, n-pentanol, and n-hexanol. The measurements were compared to the literature data and modeled with the UNIQUAC (universal quasi-chemical) activity coefficient model by taking into account also the vapor-liquid, liquid-liquid, and vapor-liquid-liquid equilibrium behaviors if present. n-Hexyl acetate showed the smallest solubility in water both in binary and ternary measurements. All four ternary systems showed similar magnitude distribution coefficients but furfural had the highest selectivity to n-hexyl acetate. Among the four systems investigated in this work, n-hexyl acetate was observed to have the best characteristics as a solvent for the extraction of furfural from water. © 2020 American Chemical Society., Export Date: 20 September 2021; Article; CODEN: JCEAA; Correspondence Address: Pokki, J.-P.; Department of Chemical and Metallurgical Engineering, P.O. Box 16100, Finland; email: juha-pekka.pokki@aalto.fi

Lignin modification opens the possibility of using it in polyol bio-based polymers, such as phenol–formaldehyde resins, polyurethanes, composites, and binders. Pine kraft lignin Indulin AT was partially depolymerized and the resulting products analyzed to determine their degree of valorization. Depolymerized lignin products were analyzed by GPC-SEC (molar mass), ∆ε-IDUS (phenolic hydroxyls), HACL (formaldehyde uptake), 13C-NMR (hydroxyl and methoxyl groups), and 1H-DOSY (molar mass distribution). The dominant parameter in lignin depolymerization by solvolysis was reaction temperature. According to the results, a higher reaction temperature decreases the average molar masses and PDI of lignin as well as the primary and secondary aliphatic hydroxyls, while simultaneously increasing the phenolic hydroxyls and formaldehyde uptake of lignin. Other variables (time, formic acid wt %, ethanol wt %, lignin load) had lesser effects. Partial depolymerization by solvolysis in mild conditions without catalyst is a viable valorization route for lignin, by which lignin properties can be significantly improved.

In this study, the utilization of silicalite–1 membrane pervaporation for butanol recovery from an acetone-butanol-ethanol (ABE) fermentation broth solution was investigated. In particular, the negative effect of butyric acid on the pervaporation performance was tested. The presence of butyric acid was observed to decrease both the butanol flux and selectivity of the membrane. Clear relation between the severity of the decreased performance and the amount of butyric acid was observed. Increasing the pH of the feed solution was observed to improve butanol pervaporation in the presence of butyric acid. In pervaporation of ethanol, butanol and butyric acid, there are significant interactions in adsorption and diffusion between the components. The presence of butanol restricts the permeation of ethanol while the butanol permeation is restricted by the presence of butyric acid. The effects likely arise from adsorptive competition and are further amplified due to the rates of diffusion. In addition, butyric acid exposure may change the membrane properties over time, although they may be restored by heating. The results suggest that the selective recovery of butanol with a silicalite–1 membrane is not feasible if the concentration of butyric acid is significant and the pH value in the solution is low.

Industrial activities and urbanization produce effluents that contain metals and anions such as sulphate and have led to deteriorating water quality in many countries. With the growing significance of a bio-based economy and increasing environmental challenges, there is a pressing need to look for more sustainable, economic and effective water treatment solutions. Sorption for pollutant removal has emerged as an alternative treatment method due to its many advantages. This thesis work studied different modification methods for two Finnish lignocellulosic biomasses: sawdust and peat, to produce biosorbents. Acid-modified sawdust (Citric acid-SD) and peat (HCl-Peat) were used for metal and metalloid removal from metallurgical wastewater, urban runoff and mine drainage, all of which had very low initial ion concentrations. The removal efficiency of the biosorbents was compared to that of two commercial mineral sorbents, M10 (mainly magnesite and quartz) and T5M5 magnetite. A novel peat-based anion exchanger (PG-Peat) was developed for sulphate removal from mine water and acid mine drainage (AMD) which contained high sulphate concentrations. The biosorbents, Citric acid-SD and HCl-Peat, effectively removed Ni (65%) and Cr (50%), respectively from metallurgical wastewater. Excellent Zn removal (~100%) was achieved by M10 in both metallurgical wastewater and urban runoff. The biosorbents performed very well in Cr and Cu removal (>70%) from urban runoff. Natural peat performed much better than HCl-Peat in Ni and As removal (80–85%) from mine drainage, although the HCl modification improved the wettability and settling properties. Sulphate removal by PG-Peat was pH-dependent (optimum pH: 2) and the biosorbent exhibited exceptional sorption capacity under acidic conditions (max. capacity 189.5 mg/g) in synthetic sulphate solution due to the presence of protonated amine groups at low pH in addition to quaternary ammonium groups. Treatment of real mine water also show, Tiivistelmä Teollinen toiminta ja kaupungistuminen tuottavat jätevesiä, jotka sisältävät metalleja ja anioneja kuten sulfaattia, ja ovat johtaneet veden laadun heikkenemiseen monissa maissa. Biopohjaisen talouden merkityksen kasvun ja lisääntyvien ympäristöhaasteiden myötä on tarve etsiä kestävämpiä, taloudellisempia ja tehokkaampia vedenkäsittelyratkaisuja. Sorptiosta on tullut varteenotettava käsittelymenetelmä saasteiden poistoon sen monien etujen vuoksi. Tässä väitöstyössä tutkittiin erilaisia modifiointimenetelmiä biosorbenttien tuottamiseen kahdesta suomalaisesta lignoselluloosa biomassasta, sahanpurusta ja turpeesta. Happomodifioitua sahanpurua (sitruunahappo-sahanpuru) ja turvetta (HCl-turve) käytettiin metallien ja metalloidien poistoon metallurgisen teollisuuden jätevedestä, kaupunkien hulevesistä ja kaivoksen kuivatusvesistä, joissa kaikissa oli alhaiset ionipitoisuudet. Biosorbenttien poistotehokkuutta verrattiin kahden kaupallisen mineraalisorbentin, M10:n (pääasiassa magnesiittia ja kvartsia) ja T5M5-magnetiitin, poistotehokkuuteen. Uusi turvepohjainen anioninvaihtaja (PG-turve) kehitettiin sulfaatin poistoon kaivosvesistä ja happamista valumavesistä, jotka sisälsivät korkeita sulfaattipitoisuuksia. Kehitetyt biosorbentit (sitruunahappo-sahanpuru ja HCl-turve), poistivat tehokkaasti nikkeliä (65%) ja kromia (50%) metallurgisen teollisuuden jätevedestä. Erinomainen sinkinpoisto (~ 100%) saavutettiin M10:llä, sekä metallurgisen teollisuuden jätevedestä, että hulevedestä. Biosorbentit toimivat erittäin hyvin kromin ja kuparin poistossa (>70%) hulevesistä. Modifioimaton turve suoriutui paljon paremmin kuin HCl-turve nikkelin ja arseenin (80–85%) poistossa kaivoksen kuivatusvesistä, vaikka happokäsittely paransi turpeen kostumis- ja laskeutumisominaisuuksia. PG-turpeen sulfaatin poistokyky riippui pH-arvosta (optimi-pH: 2), ja biosorbentilla oli erinomainen sorptiokyky happamissa olosuhteissa synteettiselle sulfaattiliuokselle (maksimikapasiteetti 189.5 mg

Boreal peatlands with low iron availability are a potential, but rarely studied, source for the isolation of bacteria for applications in metal sorption. The present research focused on the isolation and identification of Actinobacteria from northern Finland, which can produce siderophores for metal capture. The 16S rDNA analysis showed that isolated strains belonged to Firmicutes (Bacillus sp.) and Actinobacteria (Microbacterium sp.). The culture most efficiently producing siderophores in the widest array of the media was identified as Microbacterium sp. The most appropriate media for siderophore production by the Microbacterium strain were those prepared with glucose supplemented with asparagine or glutamic acid, and those prepared with glycerol or fructose supplemented with glutamic acid. The microorganism obtained and its siderophores were used to develop Sphagnum moss-based hybrid biosorbents. It was showed that the hybrid sorbent could bind nickel ions and that the nickel removal was enhanced by the presence of siderophores. Bacterial cells did not have a significant effect on sorption efficiency compared to the use of siderophores alone. The microbial biosorbent could be applied in the final effluent treatment stage for wastewater with low metal concentrations.

A novel bio-based anion exchanger was developed to remove sulphate from synthetic solutions and mine water. Different modification parameters such as chemical dosage and reaction time were tested when using a unique combination of branched polyethylenimine (PEI) and glycidyltrimethylammonium chloride (GTMAC) to produce an aminated biosorbent (termed PG-Peat). The novel and environment-friendly modification method was shown by FTIR and XPS analyses to be able to introduce quaternary ammonium and N-H groups into PG-Peat. The optimal modification conditions (PEI: 0.26 mmol/g, GTMAC: 0.0447 mol/g, reaction time: 18 h) resulted in the maximum sulphate uptake capacity (189.5 ± 2.7 mg/g) with a partition coefficient value of 0.02 mg/g/μM under acidic conditions. At low pH, amine groups on the peat surface became cationized, thereby resulting in a higher sulphate removal capacity. Batch sorption tests using PG-Peat exhibited rapid sulphate sorption after only five minutes of contact. The sulphate uptake by PG-Peat was unaffected by the presence of varying chloride concentrations, while slightly lower uptake capacity was observed when different concentrations of nitrate were present. The biosorbent showed high recyclability, which was revealed in regeneration studies. Tests were performed involving real mine water, where PG-Peat showed its potential to be a highly efficient biosorbent for sulphate removal at low pH values, indicating its suitability for treating acidic mine waters.

Biological sulfate removal is challenging in cold climates due to the slower metabolism of mesophilic bacteria; however, cold conditions also offer the possibility to isolate bacteria that have adapted to low temperatures. The present research focused on the cold acclimation and characterization of sulfate-reducing bacterial (SRB) consortia enriched from an Arctic sediment sample from northern Finland. Based on 16S rDNA analysis, the most common sulfate-reducing bacterium in all enriched consortia was Desulfobulbus, which belongs to the δ-Proteobacteria. The majority of the cultivated consortia were able to reduce sulfate at temperatures as low as 6 °C with succinic acid as a carbon source. The sulfate reduction rates at 6 °C varied from 13 to 42 mg/L/d. The cultivation medium used in this research was a Postgate medium supplemented with lactate, ethanol or succinic acid. The obtained consortia were able to grow with lactate and succinic acid but surprisingly not with ethanol. Enriched SRB consortia are useful for the biological treatment of sulfate-containing industrial wastewaters in cold conditions.

Lignins have polyphenolic structures, making them candidates to replace phenols and polyphenols in polymers. Lignins are highly recalcitrant, making their refining challenging, requiring harsh temperatures and pressures. Lignins could be partially modified under milder conditions for their use in biopolymers. The main purpose of this research was to upgrade Indulin AT, a kraft pine lignin, to enhance its properties. The first part of this thesis dealt with formic acid aided pressurized hot water extraction (FAPHWE) of hemicelluloses from birch hardwood as the first step in separating the components of a lignocellulosic feedstock (LCF). More than half of the hemicelluloses were extracted as hydrolysis products, while keeping the cellulose hydrolysis products in the extract under 5% and the lignin under 3%. In the second part of this work, a method to determine the amount of phenolic hydroxyl groups (OHph) in lignins was assessed. The Δε IDUS method was found to be useful for comparing the OHph of pine kraft and birch milox lignins, albeit not as precise as carbon-13 nuclear magnetic resonance spectroscopy (13C-NMR). The third part of this thesis explored the tuning of the molar mass (MM) and OHph of Indulin AT by aqueous ethanol fractionation. The results showed that a higher water content favored the extraction of fractions with low MM and low OHph. A high ethanol content favored the extraction of fractions with medium MM and high OHph. A 50–60 wt% ethanol content allowed for near complete solubilization of Indulin AT, which could be beneficial for a single-phase chemical reaction. The fourth part of this research dealt with the depolymerization of Indulin AT in an ethanol-water solvent with formic acid as hydrogen donor. The properties of interest were MM, polydispersity (PDI), OHph, and formaldehyde uptake capability (FUC). The results of the reaction were affected predominantly by temperature. Higher temperatures led to lower MM and PDI, and higher, Tiivistelmä Ligniini on rakenteeltaan polyfenoli, mikä tekee siitä mahdollisen fenolien korvaajan polyfenolien valmistuksessa. Ligniinin rakenne on hyvin kestävä, mikä tekee sen jalostuksesta haastavaa vaatien usein korkean lämpötilan ja paineen käyttöä. Tästä huolimatta ligniiniä voidaan tietyssä määrin muokata miedommissa olosuhteissa, mikä lisää sen käyttökelpoisuutta biopolymeerien raaka-aineena. Tämän tutkimuksen tarkoitus oli jalostaa Indulin AT -kraft ligniiniä siten, että sen ominaisuudet paranevat. Aluksi väitöstyössä tarkasteltiin puun hemiselluloosan muurahaishappokatalysoidun kuumavesiuutton soveltuvuutta lignoselluloosaraaka-aineiden fraktioinnin ensimmäiseksi vaiheeksi. Yli puolet hemiselluloosasta voitiin uuttaa monosakkarideiksi samalla, kun selluloosasta uuttui alle 5 % ja ligniinistä alle 3 %. Seuraavaksi arvioitiin fenolisten hydroksyyliryhmien määritysmenetelmää. Δε IDUS metodin havaittiin olevan hyödyllinen ainakin sulfaattimenetelmän havupuuligniinien ja Milox-prosessin koivuligniininäytteiden vertailussa, vaikkakaan se ei ole yhtä tarkka kuin ydinmagneettiseen resonanssispektroskopiaan (NMR) perustuva analyysi. Tämän jälkeen tutkittiin mahdollisuuksia tuottaa etanoli-vesiliuosfraktioinnilla jakeita, joissa ligniinillä on haluttu molekyylikoko ja fenolisten hydroksyyliryhmien pitoisuus. Tulokset näyttivät, että korkea vesipitoisuus suosii pienen molekyylikoon ja matalan OHph -pitoisuuden sisältäviä jakeiden uuttumista. Korkea etanolipitoisuus suosii keskikokoisen molekyylikoon jaetta, jossa ligniinillä on korkea OHph -pitoisuus. 50–60 m-% etanolipitoisuudessa Indulin AT liukenee lähes täydellisesti, mikä voi olla edullista kemiallisten reaktioiden toteuttamiseen yhdessä faasissa. Lopuksi tutkimuksessa tarkasteltiin ligniinin osittaista depolymerisointia etanoli-vesiliottimessa muurahaishapon toimiessa vetylähteenä. Tarkasteltavat tuotteen ominaisuudet olivat molekyylikoko, polydispersiteetti, fenolisten hydroksyyliryhmien määrä ja formalde

This study was aimed at examining the possible utilization of iron-rich groundwater treatment sludge in the synthesis of zerovalent iron (ZVI) as a conjugate with kaolin clay (Slu-KZVI), and its application for vanadium adsorption from aqueous solutions. Iron was extracted from the sludge using 1 M HCl and was used in ZVI synthesis by the sodium borohydride reduction method. The characteristics and performance of Slu-KZVI were compared to a kaolin modified with synthetic iron (FeCl₃·6H₂O) (Syn-KZVI). Adsorption results showed a competitive performance by both classes of KZVI, with Syn-KZVI slightly outperforming Slu-KZVI. X-ray photoelectron spectroscopy, X-ray diffraction and transmission electron microscopy confirmed the formation of Fe⁰ on the core-shell structure of both modified adsorbents. In addition, the surface analysis of Slu-KZVI indicated the presence of P and Ca to a small extent, originating from the sludge. Both classes of sorbents performed better in solutions with acidic and neutral pH values (3–7). Surface complexation was thought to be the primary mechanism whereas simultaneous V(V) reduction and Fe oxidation (redox) reactions may also have taken place to some extent. A sorption test with groundwater confirmed that adsorbents were able to reduce vanadium to a very low concentration.

Levulinic acid derived from biomass is a versatile platform molecule, which can be used in manufacturing different compounds to replace fossil-based chemicals. In this study, the effect of sulfolane as solvent in sulphuric acid catalysed levulinic acid production from glucose was investigated. The broad sulfolane concentration range was systematically studied and a kinetic model was developed to describe the levulinic acid production. A significant increase in glucose conversion rate was observed when the proportion of sulfolane in the solvent mixture was increased. The maximum selectivity of the levulinic acid production was found to be slightly over 50% and independent of the solvent composition. Thus, with sulfolane solvent, the same yields can be obtained in a significantly shorter time or at a lower temperature as when water is used as solvent. Sulfolane was also found to keep the generated by-products in soluble form. This will decrease fouling of the process equipment, which has been a major issue in designing of levulinic acid production processes.

In this study the interactions between ethanol and water penetrating in a supported polydimethylsiloxane membrane were investigated both using experimental and mathematical modelling work. To reach comprehensive analysis of the membrane performance and the penetrant interactions, the experimental work included a wide range of pervaporation and vapor permeation experiments with pure and binary ethanol-water mixtures. A Maxwell-Stefan model was used to further analyze the membrane performance with a Flory-Huggins formulation to describe the sorption behavior. According to the formed model, both water and ethanol permeation are slowed down from the permeation rates observed with pure feeds and in binary permeation especially the experimental ethanol flux is lower than the flux expected by the model. This suggests that the interactions between the penetrants in PDMS are high resulting to decreased diffusion rate of both ethanol and water.

Ferric groundwater treatment residual (Fe-GWTR) collected from a Finnish groundwater treatment plant were recovered for use after acid dissolution as an iron source for an inorganic-organic hybrid material. Acid dissolution, performed with 1 mol/L hydrochloric acid and mixing for one hour at room temperature, was determined as the optimal condition based on a high Fe concentration and low concentration of interfering elements. Peat modification was conducted at pH values of 3, 5 and 7 with both a commercial iron reagent (FeCl3·6H2O) and Fe-GWTR solution for comparison. A modification pH of 3 resulted in the highest vanadium removal efficiency for both iron sources. The isoelectric point (pHIEP) of Fe-GWTR-modified peat at pH 3 (Fe-GWTR-P3) was found to be 5.0. After modification, it was confirmed that BET surface area and pore volume of the peat were enlarged. Maximum capacity was found to be around 16 mg/g with a 24-hour contact time at pH 4 and a good fit was achieved with the Redlich-Peterson isotherm model. The kinetic data followed the Elovich equation, which refers to the chemisorption mechanism. According to intra-particle diffusion and Boyd models, the adsorption was a two-step diffusion process, with intra-particle diffusion being the slowest step. This study demonstrates that Fe-GWTR could safely be used as an iron source for biomass modification, and Fe-GWTR-P3 could be used as a low-cost and effective sorbent for vanadium-containing wastewater treatment.

Lignin solubility is a varying property, as depending on the type of lignin and its origin, its solubility in different solvents will differ. This is due to the highly heterogeneous nature of lignin. Solubilizing lignin could improve its potential valorization by making it more conducive to chemical reactions. Solvent fractionation could be utilized as the first step in lignin refining to adjust some of its properties before further processing. It is known that kraft lignin is completely soluble in alkaline solvents such as aqueous NaOH. The purpose of this study was to assess the solubility of Indulin AT lignin in aqueous ethanol solvents and to determine the useful properties of the resulting fractions: namely, molar mass distribution and phenolic hydroxyl groups. The highest concentration of lignin was achieved in 60 wt% ethanol solution with 235.89 g/L at a solid-to-liquid ratio of 300 gLignin/LSolvent. The original lignin had a mass average molar mass of 4.7 kDa. When only water was utilized, the average molar mass of the dissolved fraction was between 1 and 2 kDa and the molecular size distribution was mostly between 0.1 and 1 kDa. When using pure ethanol, the molecular size distribution ranged from 0.1 kDa to 10 kDa, with a mass average molar mass between 1 and 1.3 kDa. With an ethanol content in the solvent higher than 90 wt%, the bigger molar mass molecules (>10 kDa) could be separated as the insoluble fraction. Additionally, the polydispersity of both fractions decreased with an ethanol concentration above 80 wt%. The hydroxyl group content of the insoluble fraction was higher when fractionating with less than 20 wt% ethanol, whereas with 20 wt% ethanol and higher, the soluble fraction retained most of the phenolic hydroxyls. Fractionating lignin prior to use or further processing may be potentially beneficial if the lower molar mass molecules can be used as they are, leaving only the higher molar mass molecules to be further processed or burned f

Sphagnum moss extract residue (SMER), obtained after pressurized hot water extraction, was modified with Fe(III) and investigated for phosphate sorption. Although moss extract contains value-added compounds, SMER is considered to be waste until suitable uses can be developed. The effect of modification conditions were investigated, i.e. different initial Fe(III) concentrations (0.024, 0.048 and 0.072 mol/L Fe3+) and modification pH values (5, 7 and 9). A modification pH of 5 and the highest initial Fe(III) concentration (0.072 mol/L Fe3+) resulted in the highest phosphate removal efficiency, and thus was selected for further study. The removal efficiency was found to decrease with increasing pH in the range of 3–9. Maximum removal efficiency (82%) for phosphate sorption was observed at pH 3 after 24 h contact time (dosage 2 g/L, initial concentration 15 mg P/L). With increased contact time, the phosphate removal efficiency improved and reached equilibrium within 48 h. The Elovich model was found to provide the best fit to the kinetic data. A capacity of 9–13 mg P/g was obtained with a 24-h contact time at pH 4. A good fit was achieved with the Redlich–Peterson equation. FTIR analysis confirmed that carboxylic acid groups were involved in the modification process. X-ray diffraction analyses showed that amorphous two-line ferrihydrite was precipitated onto SMER, which was supported by X-ray photoelectron spectroscopy analyses.

Peat is an excellent material for metal sorption since it naturally contains different kinds of functional groups that can sorb metal cations from water. The main objective of this work was to test low-cost treatment (acid and alkali) methods for natural peat, which would improve the settling properties of peat particles while maintaining its metal removal efficiency. Particularly, the poor settling properties of peat hinder its practical application. The study revealed that NaOH-treated peat (0.1 M) had excellent settling properties and could be applied in wastewater applications having mixing and settling systems without a settling aid. The superior leaching of humic and fulvic acids in alkaline treatment caused a change in morphology, making it a harder and sticky material. Moreover, the NaOH-treated (0.1 M) peat was proven to be the most efficient material for nickel removal followed by the HCl-treated (0.2 M) peat, citric acid-treated (0.16 M) peat and water-treated peat. A higher temperature and longer time slightly increased the Ni removal efficiency with NaOH-treated peat material. The settling of HCl-treated peat was studied further using polyacrylamide flocculants (cationic, neutral, anionic). Cationic flocculants performed best and the cationic charge density also had an effect on the flocculation performance of peat particles. This study provides further evidence that peat can be applied in the treatment of metal-containing wastewaters.

The aim of this research was to convert potato peel waste (PPW) to single cell protein (SCP), and to extract valuable phenolic compounds from the spent medium. PPW is an abundant by-product of potato processing industry, consisting mostly of starch, fibre and protein in a form of watery sludge. The PPW from a chip manufacturing plant was pre-treated with sulphuric acid, and used as a substrate for an acidophilic Scytalidium acidophilum fungus under non-aseptic conditions. The produced SCP had a promising amino acid composition to be used in animal feed. Phenolic compounds were not recovered from the spent medium, most likely due to the low pH in the medium. The present findings suggest that PPW is a suitable raw material for acidophilic SCP production, whilst the extraction of phenolic acids would require milder cultivation conditions or separation before pre-treatments of SCP production. The BOD5 of the PPW was reduced by in 98% due to fungal cultivation. Thus the feed production also served as an efficient means for reduction of organic load in the PPW.

Extraction of starch from potato leads to formation of potato fruit juice (PFJ), which consists of proteins, fibers, starch and water. PFJ contains 1% – 3% [w/w] of proteins, including protease inhibitors that are potentially valuable for various applications, and could thus bring added value to the potato industry. The use of proteins of PFJ in bioactive form is limited by lack of benign and cost-efficient concentration technologies. The present approach combines a previously introduced low-temperature mechanical vapor compression evaporation technology with option to enzymatic viscosity management in case of high-viscosity fluids. In pilot-scale evaporation, an increase of solid content from 10% to 40% was achieved without major technical challenges. The proposed method offers a low-energy means for the concentration potato industry wastewater and reclamation of valuable proteins in active form.

In the sugar platform of biorefining, the complex polymeric structure of lignocellulose biomass is degraded into sugars, which are utilized by microbial cells in the further processing steps. The reaction steps in both biomass degradation and microbial fermentation processes involve multiphase reactions in which mass transfer and reaction kinetics often play a key role. The aim of this thesis is to characterize the effect of these conditions on enzymatic hydrolysis of cellulose and utilization of sugars by aerobic microbes. These types of liquid-solid (cellulose hydrolysis) and liquid-gas (microbial cultivation) systems are typically very demanding on the reactors that are used in the process. By the fed-batch process utilized in this work, sufficient mixing in enzymatic hydrolysis of cellulose is achieved even with high final substrate concentration. One of the main outcomes of this work is the kinetic model that concentrates on the kinetics of fed-batch process by discretizing the substrate into subpopulations. By using this approach, the model parameters were identified in an adequate manner, and the poorly identified parameters could be sorted out. Parameter identifiability has been an issue in previous models for enzymatic hydrolysis of cellulose. Based on the experiments and modelling studies, it can be concluded that the enzymes remain intact for time scales relevant for the hydrolysis process. Thus, the decrease in the hydrolysis rate found in many literature studies is probably mostly due to substrate-enzyme interactions rather than denaturation of the enzyme. In aerobic cell cultivations, the mixing and mass transfer conditions are often more critical for the process performance. In this work, we studied the performance and suitability of alternative reactor types to be used in aerobic cell cultivations and obtained some promising results. In addition, the thesis presents a modelling approach to study the effect of process conditions on metabolism, Tiivistelmä Biojalostuksen sokerialustassa lignoselluloosapohjaisen biomassan monimutkaista polymeerirakennetta muokataan ja sieltä vapautetaan monomeerisia sokereita, joita voidaan edelleen hyödyntää jatkojalostuksessa. Monet jatkojalostusprosessit käyttävät mikrobeja, joiden aineenvaihdunnassa sokereita voidaan jalostaa arvokkaammiksi tuotteiksi ns. fermentointiprosesseissa. Tämän väitöstyön tarkoitus on tutkia reaktio- ja aineensiirtokinetiikan vaikutusta selluloosan entsymaattiseen hydrolyysiin ja aerobisiin mikrobifermentointeihin. Näistä ensimmäinen on neste-kiintoainesysteemi ja jälkimmäinen neste-kaasusysteemi, ja tällaiset prosessit asettavat tyypillisesti merkittäviä vaatimuksia niissä käytettäville reaktoreille. Tässä työssä hyödynnettiin kiinteän raaka-aineen vähittäistä syöttöä (ns. fed-batch prosessi) selluloosan hydrolyysissä, jolloin sekoitus voidaan pitää riittävänä suurillakin kiintoainemäärillä. Työn merkittävin tuotos on kineettinen malli, jossa hyödynnetään fed-batch prosessia ja koedataa osittamalla mallinnusyhtälöt raaka-aineen syöttöajan perusteella. Tällä tavalla mallin parametrit saatiin identifioitua kohtuullisella tarkkuudella sekä eriteltyä huonosti identifioituneet parametrit. Mallin parametrien identifiointi on ollut ongelmallista monissa vastaavan tyyppisissä malleissa aiemmin. Kokeiden ja mallinnustulosten perusteella voidaan sanoa, että hydrolyysissä käytettävät entsyymit pysyvät aktiivisina prosessin aikana, ja usein todettu hydrolyysin hidastuminen johtuu ennemmin kiinteän kuidun ja entsyymien vuorovaikutuksen muutoksista kuin entsyymin denaturoitumisesta. Aerobisiin mikrobikasvatuksiin liittyen tässä työssä tutkittiin vaihtoehtoisten reaktorityyppien hyödyntämistä, joista saatiin myös lupaavia tuloksia. Lisäksi työssä kehitettiin mallinnustyökaluja, joilla voidaan tutkia prosessiolosuhteiden vaikutusta Pichia pastoris -hiivan metaboliaan ja kasvunopeuteen. Mallissa yhdistetään hiivan kasvun kineettinen malli sekä reaktoriolosuhte

Background While transposable elements (TEs) comprise the bulk of plant genomic DNA, how they contribute to genome structure and organization is still poorly understood. Especially in large genomes where TEs make the majority of genomic DNA, it is still unclear whether TEs target specific chromosomal regions or whether they simply accumulate where they are best tolerated. Results Here, we present an analysis of the repetitive fraction of the 5100 Mb barley genome, the largest angiosperm genome to have a near-complete sequence assembly. Genes make only about 2% of the genome, while over 80% is derived from TEs. The TE fraction is composed of at least 350 different families. However, 50% of the genome is comprised of only 15 high-copy TE families, while all other TE families are present in moderate or low copy numbers. We found that the barley genome is highly compartmentalized with different types of TEs occupying different chromosomal “niches”, such as distal, interstitial, or proximal regions of chromosome arms. Furthermore, gene space represents its own distinct genomic compartment that is enriched in small non-autonomous DNA transposons, suggesting that these TEs specifically target promoters and downstream regions. Furthermore, their presence in gene promoters is associated with decreased methylation levels. Conclusions Our data show that TEs are major determinants of overall chromosome structure. We hypothesize that many of the the various chromosomal distribution patterns are the result of TE families targeting specific niches, rather than them accumulating where they have the least deleterious effects.

Barley (Hordeum vulgare L.) is a cereal grass mainly used as animal fodder and raw material for the malting industry. The map-based reference genome sequence of barley cv. ‘Morex’ was constructed by the International Barley Genome Sequencing Consortium (IBSC) using hierarchical shotgun sequencing. Here, we report the experimental and computational procedures to (i) sequence and assemble more than 80,000 bacterial artificial chromosome (BAC) clones along the minimum tiling path of a genome-wide physical map, (ii) find and validate overlaps between adjacent BACs, (iii) construct 4,265 non-redundant sequence scaffolds representing clusters of overlapping BACs, and (iv) order and orient these BAC clusters along the seven barley chromosomes using positional information provided by dense genetic maps, an optical map and chromosome conformation capture sequencing (Hi-C). Integrative access to these sequence and mapping resources is provided by the barley genome explorer (BARLEX).

Cereal grasses of the Triticeae tribe have been the major food source in temperate regions since the dawn of agriculture. Their large genomes are characterized by a high content of repetitive elements and large pericentromeric regions that are virtually devoid of meiotic recombination. Here we present a high-quality reference genome assembly for barley (Hordeum vulgare L.). We use chromosome conformation capture mapping to derive the linear order of sequences across the pericentromeric space and to investigate the spatial organization of chromatin in the nucleus at megabase resolution. The composition of genes and repetitive elements differs between distal and proximal regions. Gene family analyses reveal lineage-specific duplications of genes involved in the transport of nutrients to developing seeds and the mobilization of carbohydrates in grains. We demonstrate the importance of the barley reference sequence for breeding by inspecting the genomic partitioning of sequence variation in modern elite germplasm, highlighting regions vulnerable to genetic erosion.

The coagulation efficiency of novel coagulant aluminium formate was studied in the treatment of highly contaminated effluent from a styrene butadiene latex manufacturing plant. The coagulation behaviour of the aluminium formate was compared to the behaviour of the commonly used polyaluminium chloride and aluminium sulphate. The effects of the coagulant type and dose and coagulation pH on the treatment efficiency were studied as well as the role of polyacrylamide coagulant aid. Floc separation was done using three different methods sedimentation, filtration and centrifugation. Their functionality was evaluated as part of the coagulation performance studies. Good purification results were obtained with all of the tested coagulants, the lowest residual turbidities achieved being 0.7 NTU with aluminium formate, 1.4 NTU with polyaluminium chloride and 0.7 NTU with aluminium sulphate. It was also observed that aluminium formate is as effective as commercial coagulants and is thus a potential novel coagulant chemical due to its less harmful and biodegradable counter anion. When using only aluminium coagulants, flocs were found to be too fine to be removed by sedimentation but they could be effectively removed by filtration or centrifugation. The use of polyacrylamide was found to be useful in the sense that it enables the separation of flocs by simple sedimentation because the floc size is significantly increased. In this study new knowledge about the coagulation behaviour of highly contaminated effluent from latex manufacturing was gained and aluminium formate was proved to be promising coagulant also in industrial effluent treatment.

Hemicellulose has been extracted from birch (Betula pendula) sawdust by formic acid aided hot water extraction. The maximum amount of hemicellulose extracted was about 70 mol% of the total hemicellulose content at 170 °C, measured as the combined yield of xylose and furfural. Lower temperatures (130 and 140 °C) favored hemicellulose hydrolysis rather than cellulose hydrolysis, even though the total hemicellulose yield was less than at 170 °C. It was found that formic acid greatly increased the hydrolysis of hemicellulose to xylose and furfural at the experimental temperatures. The amount of lignin in the extract remained below the detection limit of the analysis (3 g/L) in all cases. Formic acid aided hot water extraction is a promising technique for extracting hemicellulose from woody biomass, while leaving a solid residue with low hemicellulose content, which can be delignified to culminate in the three main isolated lignocellulosic fractions: cellulose, hemicellulose, and lignin.

In the enzymatic hydrolysis of cellulose, several phenomena have been proposed to cause a decrease in the reaction rate with increasing conversion. The importance of each phenomenon is difficult to distinguish from batch hydrolysis data. Thus, kinetic models for the enzymatic hydrolysis of cellulose often suffer from poor parameter identifiability. This work presents a model that is applicable to fed-batch hydrolysis by discretizing the substrate based on the feeding time. Different scenarios are tested to explain the observed decrease in reaction rate with increasing conversion, and comprehensive assessment of the parameter sensitivities is carried out. The proposed model performed well in the broad range of experimental conditions used in this study and when compared to literature data. Furthermore, the use of data from fed-batch experiments and discretization of the model substrate to populations was found to be very informative when assessing the importance of the rate-decreasing phenomena in the model.

Silver birch (Betula pendula) is a pioneer boreal tree that can be induced to flower within 1 year. Its rapid life cycle, small (440-Mb) genome, and advanced germplasm resources make birch an attractive model for forest biotechnology. We assembled and chromosomally anchored the nuclear genome of an inbred B. pendula individual. Gene duplicates from the paleohexaploid event were enriched for transcriptional regulation, whereas tandem duplicates were overrepresented by environmental responses. Population resequencing of 80 individuals showed effective population size crashes at major points of climatic upheaval. Selective sweeps were enriched among polyploid duplicates encoding key developmental and physiological triggering functions, suggesting that local adaptation has tuned the timing of and cross-talk between fundamental plant processes. Variation around the tightly-linked light response genes PHYC and FRS10 correlated with latitude and longitude and temperature, and with precipitation for PHYC. Similar associations characterized the growth-promoting cytokinin response regulator ARR1, and the wood development genes KAK and MED5A.

Purpose: Potato fruit juice, a residue of starch industry, contains up to 2.5% [w/w] of proteins that are potentially valuable raw-materials of food, cosmetic, and pharma industries. The recovery of protein from the potato fruit juice is limited by the lack of industrially feasible concentration and separation technologies. The present research thus aimed at development of such process for the separation of active protease inhibitors from potato fruit juice. Methods: Low temperature mechanical vapor recompression evaporation was applied for concentration of potato fruit juice followed by ethanol precipitation for recovery of active proteins. The effects of precipitation temperature and precipitative agents were investigated employing response surface modeling methodology. Results: Concentration of potato fruit juice by evaporation was successful without loss of trypsin inhibition activity. Precipitation using 6.5 M ethanol at low temperature (0–+4°C) was found suitable for the recovery of active protease inhibitors from the concentrate. Piloting at starch industry yielded 50% of total proteins, with a high quantity of active protease inhibitors and a minor inclusion of other proteins. Conclusion: Concentration by low-temperature evaporation, followed by ethanol precipitation of protease inhibitors at optimized temperature, is an attractive option for valorization of potato fruit juice.