0000000001004206
AUTHOR
Hannu Pakkanen
showing 39 related works from this author
Correlation of wood-based components and dewatering properties of waste activated sludge from pulp and paper industry.
2010
Large amounts of wet sludge are produced annually in municipal and industrial wastewater treatment. Already in pulp and paper industry, more than ten million tons of primary sludge, waste activated sludge, and de-inking sludge is generated. Waste activated sludge contains large quantities of bound water, which is difficult to dewater. Low water content would be a matter of high calorific value in incineration but it also has effects on the volume and the quality of the matter to be handled in sludge disposal. In this research waste activated sludges from different pulp and paper mills were chemically characterised and dewatered. Correlations of chemical composition and dewatering properties…
Alkali consumption of aliphatic carboxylic acids during alkaline pulping of wood and nonwood feedstocks
2013
Abstract The carbohydrate degradation products have been examined, which are formed during the conventional kraft pulping of a softwood, hardwoods, bamboo, and wheat straw as well as soda and soda-anthraquinone pulping of wheat straw. The focus was on “volatile” acids such as formic and acetic acids and “nonvolatile” hydroxy monocarboxylic and dicarboxylic acids. The different consumption profiles were obtained for the charged alkali required for the neutralization of these aliphatic acids depending on the feedstock and the cooking method. The relative composition of the acid fraction in the black liquors of softwood and hardwood and nonwood feedstocks showed characteristic variations. Howe…
Combustion properties of spruce black liquor droplets : Sulfur-free pulping and influence of hot-water pretreatment
2016
Hot-water pretreatment of lignocellulosics prior to sulfur-free alkaline pulping is an interesting approach for recovering value-added carbohydrate- and lignin-derived materials. This paper investigated the chemical composition variations and combustion properties of the black liquors (BLs) from three different cooking processes: two sulfur-free soda-anthraquinone (soda-AQ) and oxygen-alkali (O2-NaOH) cooks and kraft cook, before and after hot-water pretreatment of the spruce sawdust. Relatively less aliphatic acids but more lignin were present in the BLs after hot-water pretreatment as cooking time prolonged. In general, the burning time decreased as follows: soda-AQ BL > O2-NaOH BL ≅ kraf…
Endogenous AhR agonist FICZ accumulates in rainbow trout (Oncorhynchus mykiss) alevins exposed to a mixture of two PAHs, retene and fluoranthene
2022
AbstractMultiple studies have reported synergized toxicity of PAH mixtures in developing fish larvae relative to the additive effect of the components. From a toxicological perspective, multiple mechanisms are known to contribute to synergism, such as altered toxicodynamics and kinetics, as well as increased oxidative stress. An understudied contributor to synergism is the accumulation of endogenous metabolites, for example: the aryl hydrocarbon receptor 2 (AhR2) agonist and tryptophan metabolite 6-Formylindolo(3,2-b)carbazole (FICZ). Fish larvae exposed to FICZ, alongside knock-down of cytochrome p450 (cyp1a), has been reported to induced symptoms of toxicity similar to those observed foll…
Hot-water extraction of Miscanthus × giganteus prior to soda-AQ pulping: a biorefining perspective
2018
Agricultural residues, such as giant miscanthus (Miscanthus × giganteus, a hybrid of Miscanthus sinensis and Miscanthus sacchariflorus), show a great potential for use in lignocellulosic biorefiner...
Characterization of lignin dissolved during alkaline pretreatment of softwood and hardwood
2015
Various alkaline pretreatments were applied to Scots pine (Pinus sylvestris) and silver/white birch (Betula pendula/pubescens) wood chips and the characterization of sulfur-free lignin dissolved was performed. The behavior of lignin during these pretreatments (alkali charge 1–8% NaOH, time 30–120 minutes, and temperature 130–150°C) was studied mainly in terms of lignin removal efficiency and molar mass distribution of dissolved lignin. The amount of lignin in pretreatment liquors increased along with an increase in the alkali charge of 0.8–4.4% and 0.6–3.4% of o.d. pine and birch wood, respectively. The most significant parameter affecting the molar mass of the dissolved lignin was shown to…
Combustion Properties of Birch (Betula pendula) Black Liquors From Sulfur-Free Pulping
2016
Sulfur-free pulping has an environmental advantage over the traditional kraft process. This article describes the combustion properties of the black liquors produced from silver birch (Betula pendula) sawdust using three different cooking processes: two sulfur-free cooks (soda-anthraquinone and oxygen-alkali), and one reference kraft cook. It also considers the corresponding black liquors from an integrated forest biorefinery, in which a hot-water pretreatment of feedstock was performed prior to pulping. With the same cooking time, the total burning times for the sulfur-free black liquors were higher (15–55%) than those for the conventional kraft black liquors. However, no significant diffe…
Molecular Mass Distribution of Lignin from the Alkaline Pulping of Hardwood, Softwood, and Wheat Straw
2012
Abstract The behavior of lignin during kraft (hardwood, softwood, and wheat straw) and soda-AQ (wheat straw) pulping was studied, mainly in terms of delignification degree and molecular mass distribution (MMD). In the initial delignification phase (at 140°C for 15–60 min), a prominent part of the dissolved softwood kraft lignin (18–25 g/L, MM mostly > 3,000 Da) was found in the liquid phase of chip cavities, rather than in the external bulk black liquor (5–7 g/L, MM mostly < 3,000 Da). The maximum weight average MM values ( w) of the soluble lignin under conventional cooking conditions were detected for the kraft softwood (4,100 Da), and kraft birch (3,400 Da) when the degree of delignifica…
Role of lignin and sodium carbonate on the swelling behavior of black liquor droplets during combustion
2018
AbstractA partial removal of lignin from black liquor (BL) by carbonation and lignin precipitation was studied. In lignin-lean BL droplets during combustion in a laboratory furnace at 800°C in stagnant air, the maximum swelling was decreased. This observation was interpreted as showing that the lignin content decrement is due mainly to removal of higher molar mass (HMM) lignin and that the Na2CO3content of the BL is increased. Stepwise precipitation experiments with industrial softwood and hardwood kraft BLs by carbonation (resulting in pH decrement from 13 to 9) indicated that a fraction of HMM lignin (MM >10 kDa) with a higher amount of carbohydrates precipitated more prominently and e…
Chemometric Study on Alkaline Pre-treatments of Wood Chips Prior to Pulping
2016
Alkaline pre-treatments were performed for the production of organics-containing effluents from silver/white birch (Betula pendula/pubescens) and Scots pine (Pinus sylvestris) chips prior to chemical pulping. Pre-treatment conditions were varied with respect to time (from 30 min to 120 min), temperature (130 °C and 150 °C), and alkali charge (1, 2, 3, 4, 6, and 8% of NaOH on oven-dried wood). The analytical data (total content, weight average molar mass, and molar mass distribution) on dissolved lignin were subjected to principal component analysis to examine the relationship between molar mass and molar mass distributions in lignin removed from different wood species under varying alkaline…
Delignification of bamboo (Bambusa procera acher)
2004
Abstract Delignification of bamboo ( Bambusa procera acher ) was carried out by conventional kraft and soda pulping under varying conditions to determine the relationships between selected cooking parameters (EA 14–20%, sulfidity 0–45%, maximum temperature 165 and 170 °C, and time at maximum temperature 30–95 min) and pulp properties (kappa number, viscosity, and yield). Results indicated that in order to obtain relatively low kappa numbers (17–24), high sulfidity (35–45%) at lower EA (14–16%) increased both pulp viscosity and yield compared to the case of low sulfidity (0–15%) at higher EA (16–18%). Pulp with lower kappa numbers (11–15) and acceptable viscosities (1080–1190 ml/g) can be ob…
Ecological conditions alter cooperative behaviour and its costs in a chemically defended sawfly
2018
The evolution of cooperation and social behaviour is often studied in isolation from the ecology of organisms. Yet, the selective environment under which individuals evolve is much more complex in nature, consisting of ecological and abiotic interactions in addition to social ones. Here, we measured the life-history costs of cooperative chemical defence in a gregarious social herbivore, Diprion pini pine sawfly larvae, and how these costs vary under different ecological conditions. We ran a rearing experiment where we manipulated diet (resin content) and attack intensity by repeatedly harassing larvae to produce a chemical defence. We show that forcing individuals to allocate more to coope…
Characterizing the pigment composition of a variable warning signal of Parasemia plantaginis larvae
2010
Summary 1. Aposematic animals advertise their defences to predators via warning signals that often are bright colours combined with black patterns. Predation is assumed to select for large pattern elements and conspicuousness of warning signals because this enhances avoidance learning of predators. However, conspicuousness of the colour pattern can vary among individuals of aposematic species, suggesting that warning signal expression may be constrained by opposing selection pressures. If effective warning signals are costly to produce, variation in signal expression may be maintained via physiological trade-offs. To understand the costs of signalling that might underlay both physiological …
How to fight multiple enemies : target-specific chemical defences in an aposematic moth
2017
Animals have evolved different defensive strategies to survive predation, among which chemical defences are particularly widespread and diverse. Here we investigate the function of chemical defence diversity, hypothesizing that such diversity has evolved as a response to multiple enemies. The aposematic wood tiger moth (Arctia plantaginis) displays conspicuous hindwing coloration and secretes distinct defensive fluids from its thoracic glands and abdomen. We presented the two defensive fluids from laboratory-reared moths to two biologically relevant predators, birds and ants, and measured their reaction in controlled bioassays (no information on colour was provided). We found that defensive…
Alterations in Daphnia magna exposed to enniatin B and beauvericin provide additional value as environmental indicators
2022
Mycotoxins beauvericin (BEA) and enniatin B (ENN B) affect negatively several systems and demand more studies as the mechanisms are still unclear. The simultaneous presence of contaminants in the environment manifests consequences of exposure for both animals and flora. Daphnia magna is considered an ideal invertebrate to detect effects of toxic compounds and environmental alterations. In this study, the potential toxicity and the basic mechanism of BEA and ENN B individually and combined were studied in D. magna. Acute and delayed toxicity were evaluated, and transcript levels of genes involved in xenobiotic metabolism (mox, gst, abcb1, and abcc5), reproduction, and oxidative stress (vtg-S…
Combustion behavior of kraft black liquor droplets from hot water pretreated hardwood and softwood chips
2016
This paper describes the combustion behavior of birch and spruce kraft black liquors obtained from an integrated forest biorefinery concept in which a hot water extraction of chips was performed before pulping. This pretreatment, aiming mainly at the recovery of various hemicellulose-derived materials, increased the concentrations of lignin and hydroxy acids in black liquors, compared with those in the reference black liquors without any process modification. On the other hand, the pretreatment decreased the concentrations of volatile acids and other organics (extractives and hemicellulose residues). Because of these characteristic changes, the total burning times (pyrolysis time plus char …
Organics in soda-anthraquinone black liquors from hot-water-extracted non-wood feedstocks
2019
The chemical compositions of black liquors (BLs) obtained from the soda-anthraquinone (AQ) pulping of untreated and hot-water-extracted non-wood feedstocks (okra stalk, miscanthus stalk, and wheat straw) were determined. These under-utilized renewable and widely available feedstocks could provide a cheaper source for producing fiber and precursors for manufacturing green chemicals. These BLs were mainly characterized in terms of carbohydrate-derived volatile carboxylic acids (acetic and formic acids) and non-volatile carboxylic acids (hydroxy acids) as well as lignin. Additionally, in each case, the average molar mass and molar mass distribution of the dissolved lignin were measured. Result…
Quantitative determination of the main aliphatic carboxylic acids in wood kraft black liquors by high-performance liquid chromatography-mass spectrom…
2006
The versatile characterization of organic material and especially of the significant aliphatic hydroxy acids in black liquor is of great importance, for example, in monitoring the progress of the kraft pulping process. This paper describes a simple high-performance liquid chromatographic separation method with atmospheric-pressure chemical ionization mass spectrometry (HPLC-APCI-MS) which was developed for the rapid quantitative analysis of these acids, mainly formed as the alkaline degradation products of feedstock carbohydrates. The fraction of carbohydrate degradation products is mainly composed of hydroxy monocarboxylic and volatile acids (formic and acetic acids) along with lesser amou…
Complex plant quality—microbiota–population interactions modulate the response of a specialist herbivore to the defence of its host plant
2022
Many specialist herbivores have evolved strategies to cope with plant defences, with gut microbiota potentially participating to such adaptations. In this study, we assessed whether the history of plant use (population origin) and microbiota may interact with plant defence adaptation. We tested whether microbiota enhance the performance of Melitaea cinxia larvae on their host plant, Plantago lanceolata and increase their ability to cope the defensive compounds, iridoid glycosides (IGs). The gut microbiota were significantly affected by both larval population origin and host plant IG level. Contrary to our prediction, impoverishing the microbiota with antibiotic treatment did not reduce larv…
Challenges in the use of Near Infrared Spectroscopy for improving wood quality: A review
2018
Aims of study: Forestry-related companies require quality monitoring methods capable to pass a large number of samples. This review paper is dealing with the utilization of near infrared (NIR) technique for wood analysis.Area of study: We have a global point of view for NIR applications and characterization of different kind of wood species is considered.Material and methods: NIR spectroscopy is a fast, non-destructive technique, applicable to any biological material, demanding little or no sample preparation. NIR spectroscopy and multivariate analysis serve well in laboratories where the conditions are controlled. The main challenges to NIR spectroscopy technique in field conditions are mo…
Retene, pyrene and phenanthrene cause distinct molecular-level changes in the cardiac tissue of rainbow trout (Oncorhynchus mykiss) larvae, part 1 – …
2020
Polycyclic aromatic hydrocarbons (PAHs) are contaminants of concern that impact every sphere of the environment. Despite several decades of research, their mechanisms of toxicity are still poorly understood. This study explores the mechanisms of cardiotoxicity of the three widespread model PAHs retene, pyrene and phenanthrene in the rainbow trout (Oncorhynchus mykiss) early life stages. Newly hatched larvae were exposed to each individual compound at sublethal doses causing no significant increase in the prevalence of deformities. Changes in the cardiac transcriptome were assessed after 1, 3, 7 and 14 days of exposure using custom Salmo salar microarrays. The highest number of differentiall…
Depuration of geosmin- and 2-methylisoborneol-induced off-flavors in recirculating aquaculture system (RAS) farmed European whitefish Coregonus lavar…
2019
European whitefish Coregonus lavaretus has increasingly become an important species for aquatic food production, especially in the Nordic countries. Whitefish is produced in traditional cage and pond operations, and in recirculating aquaculture system (RAS) in which, unfortunately, off-flavors and odors, mostly caused by geosmin (GSM) and 2-methylisoborneol (MIB), can accumulate in fish flesh from the circulating water. GSM and MIB have very low human sensory detection limits and, therefore, often disliked by consumers even at low concentrations. In this study, concentrations of GSM and MIB in RAS farmed European whitefish were studied by an analytical method based on headspace solid phase …
Ants Data from How to fight multiple enemies: target-specific chemical defences in an aposematic moth
2017
Animals have evolved different defensive strategies to survive predation, among which chemical defences are particularly widespread and diverse. Here we investigate the function of chemical defence diversity, hypothesizing that such diversity has evolved as a response to multiple enemies. The aposematic wood tiger moth (Arctia plantaginis) displays conspicuous hindwing coloration and secretes distinct defensive fluids from their thoracic glands and abdomen. We presented the two defensive fluids from lab-reared moths to two biologically relevant predators, birds and ants, and measured their reaction in controlled bioassays (no information on colour was provided). We found that defensive flui…
A comparative study of advanced oxidative processes: Degradation of chlorinated organic compounds in ultrafiltration fractions of kraft pulp bleachin…
2016
Oxidative pre-treatment methods such as the Fenton oxidation, ozonation, and photocatalytic treatment have been compared in reducing adsorbable organic halogens (AOX) and chlorophenolic compounds in untreated kraft pulp bleaching effluent. Their efficiency was also studied on effluent ultrafiltration fractions. The Fenton treatment removed all analyzed chlorophenolic compounds from the effluent. Ozonation and photocatalysis appeared to be much less effective methods. The efficiency of the Fenton oxidation appeared to be more pronounced in higher molecular weight effluent fractions. This suggests a novel design, where the filtration stage can be placed after the oxidation, and the high- -mol…
Challenges in the use of Near Infrared Spectroscopy for improving wood quality : A review
2017
Aims of study: Forestry-related companies require quality monitoring methods capable to pass a large number of samples. This review paper is dealing with the utilization of near infrared (NIR) technique for wood analysis. Area of study: We have a global point of view for NIR applications and characterization of different kind of wood species is considered. Material and methods: NIR spectroscopy is a fast, non-destructive technique, applicable to any biological material, demanding little or no sample preparation. NIR spectroscopy and multivariate analysis serve well in laboratories where the conditions are controlled. The main challenges to NIR spectroscopy technique in field conditions are …
Bird Data from How to fight multiple enemies: target-specific chemical defences in an aposematic moth
2017
Animals have evolved different defensive strategies to survive predation, among which chemical defences are particularly widespread and diverse. Here we investigate the function of chemical defence diversity, hypothesizing that such diversity has evolved as a response to multiple enemies. The aposematic wood tiger moth (Arctia plantaginis) displays conspicuous hindwing coloration and secretes distinct defensive fluids from their thoracic glands and abdomen. We presented the two defensive fluids from lab-reared moths to two biologically relevant predators, birds and ants, and measured their reaction in controlled bioassays (no information on colour was provided). We found that defensive flui…
Costs and benefits of plant allelochemicals in herbivore diet in a multi enemy world
2015
Sequestration of plant defensive chemicals by herbivorous insects is a way of defending themselves against their natural enemies. Such herbivores have repeatedly evolved bright colours to advertise their unpalatability to predators, i.e. they are aposematic. This often comes with a cost. In this study, we examined the costs and benefits of sequestration of iridoid glycosides (IGs) by the generalist aposematic herbivore, the wood tiger moth, Parasemia plantaginis. We also asked whether the defence against one enemy (a predator) is also effective against another (a parasitoid). We found that the larvae excrete most of the IGs and only small amounts are found in the larvae. Nevertheless, the a…
Supplementary Methods and Results from How to fight multiple enemies: target-specific chemical defences in an aposematic moth
2017
Supplementary methods and supplementary results
Electronic Supplementary Material from Ecological conditions alter cooperative behaviour and its costs in a chemically defended sawfly.
2018
The evolution of cooperation and social behaviour is often studied in isolation from the ecology of organisms. Yet, the selective environment under which individuals evolve is much more complex in nature, consisting of ecological and abiotic interactions in addition to social ones. Here, we measured the life-history costs of cooperative chemical defence in a gregarious social herbivore, Diprion pini pine sawfly larvae, and how these costs vary under different ecological conditions. We ran a rearing experiment where we manipulated diet (resin content) and attack intensity by repeatedly harassing larvae to produce a chemical defence. We show that forcing individuals to allocate more to cooper…
Molecular spectra of liquors as method of studying delignification process
2011
FTIR-spectra of dried compounds of black liquors after aspen kraft cooks of different duration were obtained. Twelve samples corresponding to changing H-factor value in limits 4-1010 were investigated. The parameters of selected bands corresponding to lignin fragments vibrations were calculated using mathematical treatment methods. It was revealed that the positions and bandwidths of these lignin bands did not change. During cook at the first stage (H-factor values 4-200) their intensities strongly increased with different rates. During the next time period when the H-factor values were more than 200 a slow phase with small changes of the bands intensities were revealed. The IR-spectra of b…
De novo Synthesis of Chemical Defenses in an Aposematic Moth
2018
Many animals protect themselves from predation with chemicals, both self-made or sequestered from their diet. The potential drivers of the diversity of these chemicals have been long studied, but our knowledge of these chemicals and their acquisition mode is heavily based on specialist herbivores that sequester their defenses. The wood tiger moth (Arctia plantaginis, Linnaeus, 1758) is a well-studied aposematic species, but the nature of its chemical defenses has not been fully described . Here, we report the presence of two methoxypyrazines, 2-sec-butyl-3-methoxypyrazine and 2-isobutyl-3-methoxypyrazine, in the moths’ defensive secretions. By raising larvae on an artificial diet, we confir…
Video from How to fight multiple enemies: target-specific chemical defences in an aposematic moth
2017
Video in slow motion showing the reaction of a blue tit to the chemical defences of a wood tiger moth
Data from: De novo synthesis of chemical defences in an aposematic moth
2019
Many animals protect themselves from predation with chemicals, both self-made or sequestered from their diet. The potential drivers of the diversity of these chemicals have been long studied, but our knowledge them, and their acquisition mode, is heavily based on specialist herbivores that sequester their defences. The wood tiger moth (Arctia plantaginis, Linnaeus, 1758) is a well-studied aposematic species, but the nature of its chemical defences has not been fully described. Here we report the presence of two methoxypyrazines, 2-sec-butyl-3-methoxypyrazine and 2-isobutyl-3-methoxypyrazine, in the moths’ defensive secretions. By raising larvae on an artificial diet, we confirm, for the fir…
Data from: How to fight multiple enemies: target-specific chemical defences in an aposematic moth
2017
Animals have evolved different defensive strategies to survive predation, among which chemical defences are particularly widespread and diverse. Here we investigate the function of chemical defence diversity, hypothesising that such diversity has evolved as a response to multiple enemies. The aposematic wood tiger moth (Arctia plantaginis) displays conspicuous hindwing colouration and secretes two distinct defensive fluids, from their thoracic glands and abdomen. We presented fluids from lab-reared moths to two biologically relevant predators, birds and ants, and measured their reaction in controlled bioassays (no information on colour was provided). We found that defensive fluids are targe…
Data from: Ecological conditions alter cooperative behaviour and its costs in a chemically defended sawfly
2018
The evolution of cooperation and social behaviour is often studied in isolation from the ecology of organisms. Yet, the selective environment under which individuals evolve is much more complex in nature, consisting of ecological and abiotic interactions in addition to social ones. Here we measured the life-history costs of cooperative chemical defence in a gregarious social herbivore, Diprion pini pine sawfly larvae, and how these costs vary under different ecological conditions. We ran a rearing experiment where we manipulated diet (resin content) and attack intensity by repeatedly harassing larvae to produce a chemical defence. We show that forcing individuals to allocate more to coopera…
Figure S4 from How to fight multiple enemies: target-specific chemical defences in an aposematic moth
2017
Differences in composition between the ‘neck’ (a) and abdominal (b) fluids of wood tiger moths. Neck fluids have a richer chemical profile, with their main compounds being carboxylic acids (see Table II in Supplementary Material 5). Photos: Janne Valkonen.
Figure S5 from How to fight multiple enemies: target-specific chemical defences in an aposematic moth
2017
Bird (a, b) and ant (c) response to pure pyrazine. Birds ate fewer oats soaked with 2-sec-butyl-3-methoxypyrazine (a; both in a concentration of 1ng/µl (P) and 0.1ng/µl (Pb)). Also, they tended to have longer latencies to approach pyrazine-soaked oats (both concentrations pooled) than control oats (b). Ant response to 2-sec-butyl-3-methoxypyrazine was, in contrast, not different from that to the control sugar solution (c).
Combustion Properties of Birch (Betula pendula) Black Liquors From Sulfur-Free Pulping
2016
Sulfur-free pulping has an environmental advantage over the traditional kraft process. This article describes the combustion properties of the black liquors produced from silver birch (Betula pendula) sawdust using three different cooking processes: two sulfur-free cooks (soda-anthraquinone and oxygen-alkali), and one reference kraft cook. It also considers the corresponding black liquors from an integrated forest biorefinery, in which a hot-water pretreatment of feedstock was performed prior to pulping. With the same cooking time, the total burning times for the sulfur-free black liquors were higher (15–55%) than those for the conventional kraft black liquors. However, no significant diffe…
Figure S3 from How to fight multiple enemies: target-specific chemical defences in an aposematic moth
2017
Results of GC-MS analysis using Selected Ion Monitoring of ions 124, 138 and 151 of the neck fluid of a single moth. Top row shows total abundance of all three ions.