Hannu Pakkanen

Hannu Pakkanen
University of Jyväskylä | JYU · Department of Biological and Environmental Science; Department of Chemistry

PhD

About

61
Publications
14,527
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449
Citations
Additional affiliations
January 2017 - present
University of Jyväskylä
Position
  • Engineer
Description
  • I work as a lab engineer in the Department of Biological and Environmental Science and the Department of Chemistry. My work includes method development and technical maintenance of the equipments used in environmental analyses and biorefining studies.
January 2000 - present
University of Jyväskylä
Position
  • PostDoc Position

Publications

Publications (61)
Article
Full-text available
1. Many specialist herbivores have evolved strategies to cope with plant defenses, with gut microbiota potentially participating to such adaptations. 2. In this study we assessed whether the history of plant use (population origin) and microbiota may interact with plant defense adaptation. 3. We tested whether microbiota enhance the performance of...
Preprint
Full-text available
Colour is often used as an aposematic warning signal, with predator learning expected to lead to a single colour pattern within a population. However, there are many puzzling cases where aposematic signals are also polymorphic. The wood tiger moth, Arctia plantaginis , uses bright hindwing colours as a signal of unpalatability, and males have discr...
Preprint
Multiple 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 causing synergism has been proposed, such as increased accumulation of PAH, saturated xenobiotic metabolism capacity, and increased oxidative stress. An...
Article
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 (...
Article
Full-text available
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-methyli...
Article
Full-text available
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...
Article
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 de...
Article
Full-text available
Wheat straw and okra stalk were studied to evaluate their potential use for integrated lignocellulosic biorefining. Besides chemical pulp, a wide spectrum of value-added by-products were prepared by hot-water extraction of the feedstocks under varying conditions (140 °C for 60 and 240 min and 150 °C for 25 and 100 min) prior to sulfur-free soda-ant...
Article
Full-text available
In the present work, okra stalk (Abelmoschus esculentus) was chemically characterized to evaluate its appropriate exploitation as a biorefinery feedstock. The chemical composition of this renewable lignocellulosic material yielding maximum up to120 tons per hectare was primarily determined by methods of wood chemical analysis. In terms of its main...
Article
Full-text available
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 (...
Article
A 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 mo...
Article
Full-text available
Agricultural residues, such as giant miscanthus (Miscanthus × giganteus, a hybrid of Miscanthus sinensis and Miscanthus sacchariflorus), show a great potential for use in lignocellulosic biorefineries. In this study, various hydrolysates were prepared from miscanthus stalks under varying temperatures (140 and 150°C) and reaction times corresponding...
Article
Full-text available
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 co...
Article
Full-text available
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...
Article
Full-text available
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 so...
Article
Full-text available
This study compared oxidative pre-treatment methods—the Fenton oxidation, ozonation, and photocatalytic treatment—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 ch...
Article
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 hyd...
Poster
Full-text available
Renewable biomass resources can be industrially utilized in a number of ways to produce chemicals, fuels, and other products. Generally a better understanding of process chemistry as well as detailed knowledge on the properties of feedstocks and products is needed. In addition, various environmental aspects on the processes are of great importance....
Conference Paper
Full-text available
Renewable biomass resources can be industrially utilized in a number of ways to produce chemicals, fuels, and other products. Along with the research for improving further the processes applied in the conventional pulp and paper industry or chemical industry, novel process concepts related to biorefining are also being developed. In all these cases...
Article
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...
Article
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,...
Article
Full-text available
ABSTRACT: 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 cha...
Article
Full-text available
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 sequestr...
Article
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 main...
Article
The molecular mass distribution of the sulfur-free lignins dissolved during the conventional soda-anthraquinone and oxygen-alkali pulping of hot-water-extracted (HWE) silver birch (Betula pendula) and Norway spruce (Picea abies) sawdust was studied to evaluate the technical usability of these lignin materials. In the birch soda-anthraquinone cooks...
Article
Full-text available
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 d...
Article
Full-text available
ABSTRACT: The influence of various cooking parameters, such as effective alkali, cooking temperature, and cooking time on the formation of high molecular mass lignin-derived and low molecular mass carbohydrates-derived (aliphatic carboxylic acids) degradation products, mainly during the initial phase of softwood kraft pulping was studied. In additi...
Thesis
Full-text available
The behavior of the main chemical constituents (lignin and carbohydrates) of some selected wood and non-wood feedstocks during alkaline delignification, and especially during its initial phase, was studied. For this purpose, conventional kraft (spruce, pine, birch, aspen, bamboo, and wheat straw), soda (wheat straw), and soda-AQ (wheat straw) cooks...
Article
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...
Book
Biocides are of utmost importance both technically and economically for the paper industry in the control of the slime formation in paper mills, on which about 200 million Euros are spent annually in Europe. There is a long list of biocide types but in this Thesis the 13 most important and most widely used biocides in papermaking and their function...
Conference Paper
Full-text available
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...
Article
Full-text available
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 con...
Article
Full-text available
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 am...
Conference Paper
Full-text available
The share of moist sawdust in the manufacturing of wood pellets has rapidly increased because of the lack of dry raw materials. However, during the drying process the thermochemical degradation of wood is taking place and some volatile organic compounds (VOCs) are released. The release of VOCs is occurring also during transportation and storage of...
Conference Paper
An interesting approach to monitoring the softwood and hardwood kraft pulping process as well as to characterizing the combustion properties of black liquors from kraft pulping is described in this presentation. It is based on measurements of low-molecular-mass aliphatic carboxylic acids (and/or “lignin monomers”) which are the main degradation pro...
Conference Paper
Full-text available
Changes in the chemical composition of wood and black liquor during kraft cooking were studied. The black liquor inside and outside the chips (briefly “bound” and “free” liquor, respectively) were separated by a laboratory equipment, which made it possible to study the transferability of reaction products during the initial phase of the cook. Diffe...
Article
The suitability of a high- performance chromatog.- atmospheric pressure chemical ionization mass spectrometry (HPLC- APCI- MS) method of analyzing carbohydrate degradation products, specifically aliphatic carboxylic acids, was tested for use in the control of kraft pulping. The anal. data correlated well with the progress of laboratory- scale conve...
Article
Full-text available
Wood and non-wood feedstocks (Scots pine, Norway spruce, aspen, silver/white birch, and wheat straw) were delignified on a laboratory-scale by conventional kraft and/or soda-AQ pulping. Changes in kappa number, viscosity, and the total contents of the pulp lignin, carboxylic acid groups (AGs), and hexenuronic acid groups (HexAs) as well as the feed...
Article
Full-text available
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 ionizati...
Conference Paper
Full-text available
Wood and non-wood feedstocks were delignified by conventional laboratory-scale kraft and soda-AQ pulping. Changes in the Kappa number, viscosity, the amount of anionic (carboxylic) groups and the content of hexenuronic acids in pulps and the fibre dimensions of different raw materials as a function of H-factor were followed. It was observed that di...
Conference Paper
Full-text available
Combustion behavior (swelling during combustion and combustion time) of the kraft black liquors varies significantly between pulp mills and also time-dependent variations within a mill occur. In addition, due to the different raw materials and pulping conditions, some further variations in these combustion properties are typically observed. Therefo...
Article
The burning behavior of different bamboo kraft black liquors (EA 14 %, 16 % and 18 % and sulfidity 25 %) was investigated. The black liquors were burnt in a laboratory furnace at 800 °C by a single droplet technique, and the burning behavior was described in terms of the duration of the most illustrative burning stages (pyrolysis and char burning)...
Article
Full-text available
Bamboo (Bambusa procera) kraft pulp was first oxygen-delignified and then alternatively bleached using the DE(D/N)D, D(EOP)DP, D(EOP)D(PO), D(EOP)QP or D(EOP)Q(PO) sequences to a brightness level of 88-90% ISO. The results indicated that, when the E stage in the DE(D/N)D sequence was reinforced with either O2 or H2O2 or simultaneously with both, a...
Article
Full-text available
Structural changes in the dissolved material (lignin and carbohydrates) of bamboo (Bambusa procera) soda and kraft black liquors occurring during acidification (pH from 12-13 to 7 and 2) were studied. Characteristic differences between soda and kraft liquors in terms of average molecular masses (Mw and Mn), polydispersity (Mw/Mn), and molecular mas...
Article
The sulfuric acid precipitation of lignin and silica was carried out with laboratory- made black liquors from soda and kraft pulping of bamboo (Bambusa procera acher) . The chemical composition of the acidified liquors was analyzed with respect to their main organic and inorganic constituents. It was found that 53- 58 % of the original lignin and 7...
Conference Paper
Bamboo (Bambusa procera acher) kraft pulp was first oxygen- delignified and then alternatively bleached using the DE(D /N) D, D(EOP) DP, D(EOP) D(PO) , D(EOP) QP or D(EOP) Q(PO) sequences to a brightness level of 88- 90 % ISO. The results indicated that, when the E stage in the DE(D /N) D sequence was reinforced with either O2 or H2O2 or simultaneo...
Conference Paper
Full-text available
Industrial aspen (Populus tremula L.) wood chips were pulped in a laboratory-scale kraft process to study the behaviour of the chemical wood components during delignification. Pulp properties (kappa number, chlorine number, and viscosity) as well as total pulp yield and the amount of rejects were determined. Changes in the fibre dimensions as a fun...
Article
Full-text available
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,...
Article
In this study, the effects of heating (190°C for 30 min) on the org. constituents (lignin, carbohydrates and aliph. carboxylic acids) of black liquors from soda- AQ (wheat straw and reed canary grass) and kraft (reed canary grass) pulping under different conditions were investigated. These data were compared to those on the combustion properties of...
Article
Full-text available
Bamboo (Bambusa procera acher) was delignified in a laboratoryscale digester by conventional kraft pulping under varying conditions. Pulps with kappa numbers in the range 12.9-56.3 and viscosities in the range 871-1319 ml g(-1) were obtained. The chemical composition of the corresponding black liquors was analysed with respect to their main organic...
Article
Full-text available
Reed canary grass (Phalaris arundinacea L.) was delignified in a laboratory- scale digester by conventional anthraquinone- soda pulping under varying conditions. The chemical composition of the corresponding black liquors was analyzed with respect to their main organic constituents. The results showed that the dry solids of the black liquors contai...
Conference Paper
Full-text available
The organic material dissolved from oxygen-alkali delignified softwood kraft pulp in the bleach liquors during the molybdate-activated hydrogen peroxide (mP) and peracetic acid (PAA) stages separately and combined with the subsequent alkaline hydrogen peroxide stage (P) was characterized. In each case, carbohydrate-derived monosaccharides obtained...

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