Hardwood Bark Research Articles

Tree bark is promising sorption material for extraction of hydrocarbons from aquatic environments (Review of world and domestic literature)

The literature data on the use of bark of coniferous and hardwood trees as a sorption material for the extraction of hydrocarbons from aquatic environments are summarized. It is shown that tree bark is an effective, widespread and cheap sorption material for removing oil and oil products from the water surface. It is also shown that the sorption characteristics of tree bark for oil and products of its processing can be increased by modification with various chemical reagents. It has been revealed that most of the publications are devoted to studies of the bark of coniferous trees as oil sorbents, most of all, the bark of Scotch pine (Pinus sylvestris). It is concluded that the limited number of publications on the use of hardwood bark as oil sorbents makes this line of research promising.

Evaluation of hardwood or softwood bark biomass as feed materials for aqueous-phase reforming gasification process

In the present study, pine (Pinus brutia) and poplar (Populus alba) tree barks, softwood and hardwood representative biomass were evaluated for production of gas biofuel, hydrogen by aqueous-phase reforming. The proximate composition, elemental composition, higher heating values (HHVs), proximate thermogravimetric and differential thermogravimetric analysis (TGA/DTG), fourier transform infrared (FT-IR), and volatile composition of these biomass materials were determined and their effect on gasification performance of the softwood and hardwood biomass were evaluated. Gasification was performed by aqueous-phase reforming of solubilized liquid fraction of the biomass materials in presence of carbon-supported Pd catalyst which was synthesized in the present study. Softwood contained significantly higher levels of ash and volatile matter, with lower hemicellulose but higher lignin content. Gasification results showed that softwood produced slightly higher amounts of hydrogen with significantly lower carbon monoxide compared to hardwood. Although solid hardwood bark composition was expected to produce more gaseous products, the results observed were opposite. The dissolution of biomass in pressured hot water prior to gasification resulted in a more dilute hydrolysate in softwood compared to hardwood, positively influencing the gasification performance. Despite of many advantages of the aqueous-phase reforming (APR) gasification process used in the present study, the process still needs to be improved further to make the process more economical. To increase the advantage of this process, new catalysts that are more robust and active and have high stability in organic-rich APR conditions should be developed.

Lactobacillus corticis sp. nov., isolated from hardwood bark.

During a study on the biodiversity of bacteria that inhabit woody biomass, we isolated a strain coded B40T from hardwood bark used as a compost ingredient in Japan. The strain, characterized as B40T, is a Gram-stain-positive, rod-shaped, non-motile, non-spore-forming and catalase-negative bacterium. This novel isolate showed growth at 30-50 °C, at pH 3.5-7.5 and in the presence of up to 4 % (w/v) NaCl. Its major fatty acids include C16:0, C18:1 ω9c and summed feature 8. The genomic DNA G+C content of strain B40T is 42.2 mol%. Results of 16S rRNA gene sequence-based phylogenetic analysis indicated that strain B40T belongs to the genus Lactobacillus and the closest neighbours of strain B40T are Lactobacillus gigeriorum 202T (95.7 %), Lactobacillus pasteurii CRBIP 24.76T (95.6 %), Lactobacillus psittaci DSM 15354T (95.4 %), Lactobacillus fornicalis TV1018T (95.4 %) and Lactobacillus jensenii ATCC 25258T (95.2 %). The amino acid sequence-based phylogenetic analyses of 489 shared protein-encoding genes showed that the strain forms a phylogenetically independent lineage in the genus Lactobacillus but could not be assigned to any known species. Strain B40T has an average nucleotide identify of <70.2 % and a digital DNA-DNA hybridization value of 19.2 % compared with the strains of other closely related Lactobacillus species. Differential genomic, phenotypic and chemotaxonomic properties, in addition to phylogenetic analyses, indicated that strain B40T represents a novel species of the genus Lactobacillus, for which the name Lactobacillus corticis sp. nov. is proposed. The strain type is B40T (=JCM 32597T=DSM 107967T).

Entrained Flow Gasification of Hardwood Bark: Experimental Characterization of Inorganic Matter versus Equilibrium and Viscosity Predictions

Entrained Flow Gasification of Hardwood Bark: Experimental Characterization of Inorganic Matter versus Equilibrium and Viscosity Predictions

Oxygen-Blown Gasification of Pulp Mill Bark Residues for Synthetic Fuel Production

Synthetic fuel production via gasification of residual biomass streams from the pulp and paper industry can be an opportunity for the mills to enable improved resource utilization and at the same time reduce the production of excess heat. This paper summarizes initial oxygen-blown gasification experiments with two bark residues from a European pulp and paper mill, i.e., a softwood bark and a hardwood bark. The gasification process was characterized by measuring syngas yields and process efficiency to find optimum operating conditions. In addition, impurities in the syngas and ash behavior were characterized. Maximum yields of CO and H2 were obtained from softwood bark and amounted to approximately 29 and 15 mol/kg fuel, respectively. Optimum cold gas efficiency was achieved at an oxygen stoichiometric ratio of λ = 0.40 and was approximately 76% and 70% for softwood bark and hardwood bark, respectively. Increased λ had a reducing effect on pollutants in the syngas, e.g., higher hydrocarbons, NH3, HCl, and soot. The situation for sulfur species was more complex. Evaluation of the bark ashes indicated that slag formation could start already from 800 °C. Furthermore, a non-intrusive laser diagnostics technique gave rapid feedback on the millisecond scale. Measured syngas temperature and water content were in good agreement with the applied reference methods.

Direct Solvent Liquefaction of Tropical Hardwood Bark and Characterization of the Resulting Bio-Oil

Ethanol, water and ethanol/water mix were used to directly liquefy Detarium senegalense bark at 500°C for 15 min. Ethanol/water mix at 50/50% weight by weight showed synergistic effect on biomass direct liquefaction, and was found to be the most effective solvent for the liquefaction of Detarium senegalense bark. Water was more active than Ethanol when both mono-solvents were evaluated. Liquefaction with 100% water yielded 46% by weight of the bio-oil, compared with 30% by weight of bio-oil yield when 100% ethanol was used. The result however, show that 50% ethanol/water showed a synergistic effect and work best to obtain 52% bio-oil on the liquefaction whereas water was found hence more active than ethanol as a single solvent with 46% and 30% bio-oil respectively.&#x0D; The GC-MS analysis of the obtained bio-oils from the three matrices confirmed the presence of phenolic compounds and aromatics such as benzenes, followed by aldehydes, long chain ketones and cyclic ketones and alcohol, esters, organic acids and ether compounds. The detected phenolic compounds were 4-ethyl-guaiacol, 2-methoxy-4-(2-propenyl)-phenol, 2-methoxy-phenol, and 2-methoxy-4-vinyl-phenol., formed from the cleavage of guaiacyl and hydroxyphenyl-type lignin with varying degrees of alcohol substitution. Understanding and evaluating the liquefied products obtained from hardwood barks, could offer valuable information on the utilization of the biomass-liquefaction products for chemical or energy production.

Thin Alginate Membranes Functionalized with Humic Acids for Removing Traces of Cu(II) from Contaminated Seawater

Humic acid (HA) could become a useful agent for removing trace amounts of Cu(II) from contaminated seawater. This study reports on the use of a thin alginate membrane (TAM) containing immobilized HA as a Cu(II) binding agent for this purpose. The removal efficiency of Cu(II) by a TAM functionalized with HA was significantly increased compared to TAM alone. In this removal method, HA extracted from hardwood bark compost was more effective in removing Cu(II) than that from peat soil.

Removal of Trace Levels of Cu(II) from Seawater by Co-precipitation with Humic Acids

To maintain performance related to fuel consumption and maneuverability, the bottom of ships are painted with antifouling paint that contains Cu2O as a biocidal pigment. However, in enclosed coastal areas around dockyards, some of the Cu(II) contained in the paint is eluted into the surrounding water. The present study examined the removal of Cu from seawater by co-precipitation with humic acids (HAs). After precipitating the HA in seawater, the amount of Cu(II) in the supernatant was colorimetrically measured by a colorimetry using bathocuproine. The removal efficiency (RE%) for micromolar Cu(II) increased with increasing initial concentrations of HAs. An RE of 90% was obtained using an HA derived from hardwood bark compost. Aromatic components in the HA that contained highly substituted acidic functional groups appeared to enhance the removal of Cu(II). The findings reported herein indicate that HAs represent a useful material for removing trace levels of Cu from seawater.

Nanoparticle Gels Obtained from Hardwood and Softwood Bark for Reinforcing of Paper

For reinforcing of paper, nanoparticle gels from black alder, birch and pine bark were obtained. Non-extracted bark and that extracted in biorefinery were used. For producing nanoparticles, the materials were destructed using the thermocatalytic destruction method and then dispersed in water medium in a ball mill. At a sufficient concentration, gel-like dispersions were obtained, which contained nanoparticles with the size ~300 nm. The effect of nanoparticle gels on the properties of paper sheets was investigated by introducing the dissolved gels in paper furnish and by covering both sides of paper sheets with nanoparticle gel coatings. It has been established that the nanoparticle fillers increase the tensile and burst strength. The nanoparticle fillers from extracted bark increase the mechanical indices to a higher extent. The coatings from nanoparticle gels considerably improve the Gurley air resistance of paper and increase the mechanical indices of paper sheets, especially burst strength. The effect of nanoparticle gel coatings is dependent on the coating thickness and gel concentration. The coatings decrease the tensile strength in a wet state.

Ecoenzymes as Indicators of Compost to Suppress Rhizoctonia Solani

ABSTRACTReports of disease suppression by compost are inconsistent likely because there are no established standards for feedstock material, maturity age for application, and application rate. The overall goal of the study was to evaluate a suite of biological indicators for their ability to predict disease suppression. Indicators included both commercial available methods for compost stability (Solvita™, respiration) and metrics of soil ecology not yet adopted by the compost industry (e.g., ecoenzymes, nematode community index). Damping-off by Rhizoctonia solani on radish was chosen as a model system given its global importance, competitiveness affected by carbon quality, and lack of disease management options for organic production. Biological indicators were evaluated for their ability to consistently differentiate among curing process, maturity, and feedstock material as a function of disease severity of a seedling bioassay and a compost extract assay to test competition with R. solani growth. Compost processed as vermicompost and anaerobic digestate were more suppressive against R. solani than windrow or aerated static pile. Mature composts were more suppressive than immature components. Feedstocks containing dairy manure and/or hardwood bark tended to have suppressive qualities. In contrast, poultry manure-based components were conducive to disease. Microbial ecoenzymes active on chitin and cellulose and nematode community indices were better predictors of disease suppressiveness than microbial respiration. These indicators are quicker than plant bioassays and could be adopted as tools to certify commercial products.

Effect of eucalyptus bark contamination during pulping of mixed southern hardwoods

The use of eucalyptus as a partial replacement for mixed southern hardwoods can result in significant amounts of eucalyptus bark being incorporated into the chips going to the digester. When eucalyptus is first harvested, the bark peels off in large sheets, which will pass through chippers designed for southern hardwood. After being cut for more than about 4–6 weeks, the bark tightens onto the bole of the tree and again passes through chippers not designed for eucalyptus. As a result, significant quantities of eucalyptus bark could go to the digester. This study describes the effect of pulping eucalyptus bark in the laboratory. A series of control studies were performed on eucalyptus and mixed southern hardwood bark. The results show that incorporating bark into the cook results in increased kappa number, decreased pulp yield, and increased alkali consumption. If the percentage of applied active alkali is increased to counteract the increased alkali consumption, increased hexenuronic acid is generated

Weed Suppression in Pumpkin by Mulches Composed of Organic Municipal Waste Materials

Field studies were conducted in 2011 and 2012 to compare mulch treatments of shredded newspaper, a combination of shredded newspaper plus turfgrass clippings (NP + grass), hardwood bark chips, black polyethylene plastic, and bare soil on weeds, insects, soil moisture, and soil temperature in pumpkins. Newspaper mulch or black plastic reduced total weed biomass ≥90%, and woodchip or NP + grass mulch each reduced total weed biomass 78% compared with bare soil under high rainfall conditions in 2011. In 2012, under low rainfall, all mulches reduced weed biomass 97% or more compared with bare soil. In both years, all mulches resulted in higher squash bug infestations than bare soil. The woodchip, newspaper, and NP + grass mulches retained higher soil moistures than bare soil or black plastic over the course of each growing season, and the woodchip and NP + grass mulches caused greatest fluctuations in soil temperature. Pumpkin yields were abnormally low in 2011 and did not differ among treatments. In 2012, all mulches produced greater total marketable pumpkin fruit weights compared with bare soil, but only black plastic, newspaper, and NP + grass mulches resulted in greater total numbers of marketable pumpkins. Overall results indicate that shredded newspaper or NP + grass mulches may be useful for organic and/or small-scale urban crop producers as sustainable alternatives to black plastic mulch; however, their weed suppression efficacy may require higher application rates with increasing moisture conditions, and they may require greater squash bug control measures than under bare soil conditions.

Adhesives formulated from bark bio-crude and phenol formaldehyde resole

Rather than replacing phenol in the synthesis of PF resole, bark-derived bio-crudes were used as an adhesive constituent by simply formulation with neat PF adhesive in this study. Bio-crude derived from white birch bark (WBB)—a typical hardwood bark and white spruce bark (WSP)—a typical softwood bark were blended with neat PF adhesive to prepare bark bio-crude formulated bio-phenol formaldehyde (BPF) adhesive (designated as bio-crude formulated BPF adhesive). It was discovered that the viable formulation ratio between bark bio-crude and neat PF adhesive depended on the bark species. WBB bio-crude could be formulated with neat PF adhesive at a formulation ratio of 50:50 (wt/wt), while WSP bio-crude can be formulated with neat PF adhesive at a higher formulation ratio up to 75:25 (wt/wt). The peak curing temperatures of the bio-crude formulated BPF adhesives were lower than that of neat PF adhesive. Activation energy for the curing of WBB bio-crude formulated BPF adhesives was higher than that for the curing of neat PF adhesive, while WSP bio-crude formulated BPF adhesive required less activation energy for curing than neat PF adhesive. Condensation between bio-crude and neat PF adhesive occured during the pre-curing process at 125°C and was confirmed by FTIR spectra. Interestingly, the introduction of bio-crude enhanced the thermal stability of the bio-crude formulated BPF adhesives at low temperatures, but as expected, thermal stability of the bio-crude formulated BPF adhesives reduced at higher temperatures and a higher formulation ratio led to lower thermal stability. At a same formulation ratio, WSP bio-crude formulated BPF adhesives showed better thermal stability than WBB bio-crude. More interestingly, the free formaldehyde emission level of 3-ply plywood bonded by bio-crude formulated BPF adhesives, in particular with the WSP bio-crude, was lower than that of the neat PF adhesive bonded plywood. Free formaldehyde emission levels from 3-ply plywood bonded with WSP bio-crude formulated BPF adhesives at the formulation ratios of 50:50 (wt/wt) and 75:25 (wt/wt) reached JIS F*** level. However, bio-crude formulated BPF adhesives reduced the tension shear strength of bonded 3-ply plywood, in particular at higher formulation ratios. At the same bio-crude formulation ratio, WSP bio-crude formulated BPF adhesives gave better tension shear strength for 3-ply plywood than the WBB bio-crude formulated BPF adhesives. Nevertheless, 3-ply plywoods bonded with bark bio-crude formulated BPF adhesives at a ratio up to 50:50 (wt/wt) still met the JIS standards with respect to tension shear strength.

Compost for Management of Weed Seeds, Pathogen, and Early Blight on Brassicas in Organic Farmer Fields

Low-input methods for addressing economic and management challenges of plant pathogens and weed seeds will advance sustainable farming practices. Objective 1 was to demonstrate that U.S. National Organic Standards (NOS) for compost are sufficient to kill plant pathogens and weed seed. Known quantities of early blight inoculum (Alternaria brassicinae) and giant crab grass (Digitaria sanguinalis) seed were enclosed in bags and inserted into manure-based compost containing different sources of C: 1) manure–silage, 2) hay, 3) softwood, and 4) hardwood. Except for the manure–silage control, treatments represented C:N ratios prescribed by NOS. Bags were removed at five times during the compost process. Both pathogenicity and seed germination were reduced to zero by following NOS guidelines. Patterns of microbial enzyme activity illustrated that labile substrates were abundant in manure–silage and hay, but limited in softwood and hardwood treatments. For Objective 2, field trials were conducted at two farms. Compost treatments were applied after the first cultivation as mulch as follows: 1) manure–silage, 2) hay, and 3) hardwood. Non-mulched plots were used as bare controls. When compost was applied at a rate of 54.8 ton/ha (20 ton/acre), compost made with hardwood bark suppressed severity of early blight disease more than compost made with softwood, hay or manure–silage.

Pattern recognition as a tool to discriminate softwood and hardwood bark fractions with different particle size

The aim of this study was to characterize the chemical composition of different granulometric fractions obtained by milling of the bark of two softwood [Norway spruce, Picea abies (L.) Karst., and Scots pine, Pinus sylvestris L.] and two hardwood species (birch, Betula pendula Roth, and eucalypt, Eucalyptus globulus Labill.), and to discriminate between them on the basis of their chemical composition content via pattern recognition techniques [principal component analysis (PCA), cluster analysis (CA), and discriminant analysis (DA)]. Bark chemical composition differed between species, and chemical variables could be used to differentiate between them. Size reduction yields granulometric fractions that are not chemically homogeneous and that can also be discriminated. Therefore, potential applications of bark in valorization programs have to carefully consider the species-specific composition and their size reduction patterns. PCA and CA were adequate tools to characterize the different bark fractions within each species. DA allowed identifying the bark samples according to species and independently from particle size. Pattern recognition statistical methods were shown to be useful tools to analyse bark fractions and chemically discriminate species and fractions.

The effect of bark on sulfur dioxide–ethanol–water fractionation and enzymatic hydrolysis of forest biomass

The focus of this study was to find out the effect of bark on SO2–ethanol–water (SEW) fractionation and enzymatic hydrolysis of forest biomass. Softwood bark was found to be more harmful than hardwood bark in both processes. For softwood, the amount of undigested wood in SEW fractionation increased with the increasing bark content, whereas the hardwood bark did not impair the fractionation of wood. The higher the softwood bark content was the lower were the yields in enzymatic hydrolysis likely due to the unproductive binding of enzymes on lignin and other compounds. Addition of surfactant Tween 20 (2% w/w on substrate) prior to enzyme more than doubled the sugar yield of bark-rich softwood pulp. Hardwood bark impaired enzymatic hydrolysis when its share was over 28%. According to a preliminary study, lignosulfonates from the carry-over liquor seem to improve the sugar yield in the enzymatic hydrolysis by acting as a surfactant.

An analysis of the larval instars of the walnut twig beetle, Pityophthorus juglandis Blackman (Coleoptera: Scolytidae), in northern California black walnut, Juglans hindsii, and a new host record for Hylocurus hirtellus

By measuring and analyzing larval head capsule widths, we determined that a northern California population of the walnut twig beetle, Pityophthorus juglandis Blackman (Coleoptera: Scolytidae), has three larval instars. We also developed rules to classify P. juglandis larval instars. Overlap in the ranges of widths among consecutive instars was addressed by fitting a distribution model to the data and determining limits for head capsule width classes and probabilities of instar misclassification. Growth ratios for laboratory and field samples of P. juglandis were consistent with the Brooks-Dyar rule and with results in the literature for other bark and ambrosia beetle species. As a consequence of branch dissection to retrieve larvae of P. juglandis, we established that northern California black walnut, Juglans hindsii (Jeps.) Jeps. ex R.E. Sm., is a host for the xylophagous “California hardwood bark beetle,” Hylocurus hirtellus (LeConte) (Coleoptera: Scolytidae), and that H. hirtellus is associated with P. juglandis beneath the bark of small diameter branches. It appears that in northern California, univoltine H. hirtellus is active in flight from early March through early May, with the majority of the adults dispersing in April. The females are the colonizing sex.

Designing the ideal habitat for entomopathogen use in nursery production

Greenhouse and nursery producers use entomopathogens (nematodes and fungi) to control soil pests. Although it is known that the physical and chemical properties of mineral soil significantly impact upon soil pathogens, the influence of soilless media used for plant production on entomopathogen performance is poorly understood. Survival and foraging distance were differently affected by sand:peat, bark and sawdust media for entomopathogenic nematodes, but not for the immobile fungus Metarhizium anisopliae. Redwood sawdust medium consistently had a negative impact upon entomopathogenic nematodes. Dividing media into individual components supported the hypothesis that redwood sawdust reduced foraging and infection abilities of S. riobrave and H. bacteriophora. Physically altering the components by adding sand significantly improved foraging and infection success for S. riobrave in media not optimum for foraging. This study is the first to highlight the importance of selecting the appropriate soilless media and pathogen species combinations to increase efficacy of biological control. H. bacteriophora was able to find hosts in a wider diversity of medium components than S. riobrave, although both nematode species performed well in peat moss and recycled plant material. These results suggest that peat moss, recycled plant material and hardwood bark are components amenable to EPN biological control programs.

Remediation potential of mulch for removing lead

Hardwood bark mulch has good physicochemical properties for the adsorption of lead (Pb(II)). Batch tests were conducted to obtain the sorption coefficient of Pb(II) in mulch. The results of the Freundlich model were not in as good agreement as for the case of the Langmuir model. In addition, a laboratory-scale mulch permeable reactive barrier (PRB) system was designed for the treatment of Pb(II)-contaminated groundwater. The mulch PRB system, using a mulch layer, can potentially be used in the subsurface for cost-effective and in situ transformation of the Pb(II) into environmentally acceptable forms. From the Pb(II) breakthrough curve, the mulch becomes saturated more quickly at higher flow rates.

Long-term Effects of Four Groundcover Management Systems in an Apple Orchard

Groundcover management systems (GMSs) are essential for fruit production, but very few long-term studies have evaluated orchard GMS sustainability. We evaluated four GMSs—pre-emergence soil-active herbicides (PreHerb), post-emergence herbicide (PostHerb), a turfgrass cover crop (Sod), and hardwood bark mulch (Mulch)—in an apple (Malus domestica Borkh.) orchard over 16 years of continuous observation. There were no consistent long-term trends in fruit yields among GMSs, although during the first 5 years, yields were lower in trees on Sod. Tree growth was greater in PostHerb and Mulch than in Sod during the first 5 years, and during the next decade, trees in Mulch plots were consistently larger than in other GMSs. Total soil nitrogen (N) and carbon (C) content, C-to-N ratios, and essential plant nutrients were much greater in the Mulch soil after 16 years of treatments. Long-term responses of trees to groundcover vegetation indicated that apple trees respond adaptively to compensate for weed and grass competition. Year-round elimination of surface vegetation with residual soil active herbicides may be unnecessary or even detrimental for orchard productivity and soil fertility in established orchards. Post-emergence herbicides that reduce weed competition primarily during the summer months may offer an optimal combination of weed suppression and soil conservation.