This paper presents the results of the analysis of the chemical composition and content of heavy metal contamination in forest logging residues, in order to assess the possibility for their further utilisation. The samples were divided into 9 groups, which included coniferous tree cones, wood, and other multi-species logging residues. The elementary composition, ash content, and calorific value were determined as energy use indicators for the samples. Additionally, the content of heavy and alkali metals, which may affect combustion processes and pollutant emissions, was tested. The high content of heavy metals may also disqualify these residues for other uses. The research shows that the test residues are suitable for energy use due to their high calorific value and low content of heavy metals. However, an increased ash content in some samples and the presence of alkali metals, causing high-temperature corrosion of boilers, may disqualify them as a potential fuel in the combustion process. The forest residues may be used in other thermal processes such as pyrolysis or gasification. A low content of heavy metals and a high content of organic matter permit the use of these residues for the production of adsorbents or composite materials.

Department of Biosystems Engineering Institute of Mechanical Engineering Warsaw University of Life Sciences SGGW Nowoursynowska 164 02 787 Warsaw Poland

Department of Process and Environmental Engineering Faculty of Mechanical Engineering Opole University of Technology Prószkowska 76 Street 45 758 Opole Poland

Faculty of Engineering Czech University of Life Sciences Prague Kamycka 129 165 21 Prague 6 Czech Republic

Łukasiewicz Research Network Institute of Ceramics and Building Materials Cementowa 8 Street 31 983 Cracow Poland

Zobrazit více v PubMed

Sobek S., Werle S. Kinetic modelling of waste wood devolatilization during pyrolysis based on thermogravimetric data and solar pyrolysis reactor performance. Fuel. 2020;261:116459. doi: 10.1016/j.fuel.2019.116459. DOI

Thorenz A., Wietschel L., Stindt D., Tuma A. Assessment of agroforestry residue potentials for the bioeconomy in the European Union. J. Clean. Prod. 2018;176:348–359. doi: 10.1016/j.jclepro.2017.12.143. PubMed DOI PMC

Braghiroli F.L., Passarini L. Valorization of Biomass Residues from Forest Operations and Wood Manufacturing Presents a Wide Range of Sustainable and Innovative Possibilities. Curr. For. Rep. 2020;6:172–183. doi: 10.1007/s40725-020-00112-9. DOI

Popp J., Kovács S., Oláh J., Divéki Z., Balázs E. Bioeconomy: Biomass and biomass-based energy supply and demand. New Biotechnol. 2021;60:76–84. doi: 10.1016/j.nbt.2020.10.004. PubMed DOI

Cutillas-Barreiro L., Fernández-Calviño D., Núñez-Delgado A., Fernández-Sanjurjo M.J., Álvarez-Rodríguez E., Nóvoa-Muñoz J.C., Arias-Estévez M. Pine Bark Amendment to Promote Sustainability in Cu-Polluted Acid Soils: Effects on Lolium perenne Growth and Cu Uptake. Water Air Soil Pollut. 2017;228:260. doi: 10.1007/s11270-017-3437-y. DOI

Su P., Granholm K., Pranovich A., Harju L., Holmbom B., Ivaska A. Sorption of metal ions from aqueous solution to spruce bark. Wood Sci. Technol. 2013;47:1083–1097. doi: 10.1007/s00226-013-0562-7. DOI

Van Vinh N., Zafar M., Behera S.K., Park H.S. Arsenic(III) removal from aqueous solution by raw and zinc-loaded pine cone biochar: Equilibrium, kinetics, and thermodynamics studies. Int. J. Environ. Sci. Technol. 2014;12:1283–1294. doi: 10.1007/s13762-014-0507-1. DOI

Baltrenas P., Vaiškunaite R. A Biofilter Containing a Biologically Active Layer of Pine Bark for Removing Volatile Hydrocarbons from Air. Chem. Pet. Eng. 2004;40:417–420. doi: 10.1023/B:CAPE.0000047658.67733.ce. DOI

Baltrenas P., Zagorskis A. Experiments on Small Biofilters Containing Activated Spruce Bark. Chem. Pet. Eng. 2005;41:492–495. doi: 10.1007/s10556-006-0006-4. DOI

Liu F., Wienke C., Fiencke C., Guo J., Dong R., Pfeiffer E.-M. Biofilter with mixture of pine bark and expanded clay as packing material for methane treatment in lab-scale experiment and field-scale implementation. Environ. Sci. Pollut. Res. 2018;25:31297–31306. doi: 10.1007/s11356-018-3102-z. PubMed DOI

Lippo H., Poikolainen J., Kubin E. The use of moss, lichen and pine bark in the nationwide monitoring of atmospheric heavy metal deposition in Finland. Water Air Soil Pollut. 1995;85:2241–2246. doi: 10.1007/BF01186167. DOI

Harju L., Saarela K.-E., Rajander J., Lill J.-O., Lindroos A., Heselius S.-J. Environmental monitoring of trace elements in bark of Scots pine by thick-target PIXE. Nucl. Instrum. Methods Phys. Res. Sect. B Beam Interact. Mater. Atoms. 2002;189:163–167. doi: 10.1016/S0168-583X(01)01031-X. DOI

Cetin M., Sevik H., Cobanoglu O. Ca, Cu, and Li in washed and unwashed specimens of needles, bark, and branches of the blue spruce (Picea pungens) in the city of Ankara. Environ. Sci. Pollut. Res. 2020;27:21816–21825. doi: 10.1007/s11356-020-08687-3. PubMed DOI

Chusova O., Nõlvak H., Odlare M., Truu J., Truu M., Oopkaup K., Nehrenheim E. Biotransformation of pink water TNT on the surface of a low-cost adsorbent pine bark. Biodegradation. 2015;26:375–386. doi: 10.1007/s10532-015-9740-7. PubMed DOI

Velmurugan P., Lee S.-M., Iydroose M., Lee K.-J., Oh B.-T. Pine cone-mediated green synthesis of silver nanoparticles and their antibacterial activity against agricultural pathogens. Appl. Microbiol. Biotechnol. 2013;97:361–368. doi: 10.1007/s00253-012-3892-8. PubMed DOI

Argun M.E., Dursun S., Karatas M. Removal of Cd(II), Pb(II), Cu(II) and Ni(II) from water using modified pine bark. Desalination. 2009;249:519–527. doi: 10.1016/j.desal.2009.01.020. DOI

Malikov I.N., Noskova Y.A., Karaseva M.S., Perederii M.A. Granulated sorbents from wood waste. Solid Fuel Chem. 2007;41:100–106. doi: 10.3103/S0361521907020085. DOI

Aniszewska M. Anatomical structure of spruce cones. Sylwan. 2002;146:85–91.

Gokdai D., Borazan A.A., Acikbas G. Effect of Marble: Pine Cone Waste Ratios on Mechanical Properties of Polyester Matrix Composites. Waste Biomass- Valorization. 2017;8:1855–1862. doi: 10.1007/s12649-017-9856-6. DOI

Jha K., Tyagi Y.K., Yadav A.S. Mechanical and thermal behaviour of biodegradable composites based on polycaprolactone with pine cone particle. Sadhana. 2018;43:135. doi: 10.1007/s12046-018-0822-1. DOI

García-García D., Balart R., Lopez-Martinez J., Ek M., Moriana R. Optimizing the yield and physico-chemical properties of pine cone cellulose nanocrystals by different hydrolysis time. Cellulose. 2018;25:2925–2938. doi: 10.1007/s10570-018-1760-0. DOI

Sirén H. Hydrophilic compounds in liquids of enzymatic hydrolyzed spruce and pine biomass. Data Brief. 2015;5:194–202. doi: 10.1016/j.dib.2015.08.026. PubMed DOI PMC

Gendek A., Aniszewska M., Malaťák J., Velebil J. Evaluation of selected physical and mechanical properties of briquettes produced from cones of three coniferous tree species. Biomass- Bioenergy. 2018;117:173–179. doi: 10.1016/j.biombioe.2018.07.025. DOI

Sen T.K., Afroze S., Ang H.M. Equilibrium, Kinetics and Mechanism of Removal of Methylene Blue from Aqueous Solution by Adsorption onto Pine Cone Biomass of Pinus radiata. Water Air Soil Pollut. 2011;218:499–515. doi: 10.1007/s11270-010-0663-y. DOI

Mahmoodi N.M., Hayati B., Arami M., Lan C. Adsorption of textile dyes on Pine Cone from colored wastewater: Kinetic, equilibrium and thermodynamic studies. Desalination. 2011;268:117–125. doi: 10.1016/j.desal.2010.10.007. DOI

Kumar N.S., Asif M., Al-Hazzaa M.I. Adsorptive removal of phenolic compounds from aqueous solutions using pine cone biomass: Kinetics and equilibrium studies. Environ. Sci. Pollut. Res. 2018;25:21949–21960. doi: 10.1007/s11356-018-2315-5. PubMed DOI

Pholosi A., Ofomaja A., Naidoo E. Effect of chemical extractants on the biosorptive properties of pine cone powder: Influence on lead(II) removal mechanism. J. Saudi Chem. Soc. 2013;17:77–86. doi: 10.1016/j.jscs.2011.10.017. DOI

Pholosi A., Naidoo E.B., Ofomaja A.E. Sequestration of As(III) pollutant from water using chemically activated pine cone biomass: Evaluation of interaction and mechanism. Int. J. Environ. Sci. Technol. 2019;16:6907–6920. doi: 10.1007/s13762-019-02283-w. DOI

Pholosi A., Naidoo E.B., Ofomaja A.E., Ramasami P., Bhowon M.G., Laulloo S.J., Wah H.L.K. Emerging Trends in Chemical Sciences. Springer International Publishing; Cham, Germany: 2017. Removal of Ni(II) and Co(II) from Aqueous Solution Using Pine Cone: A Mechanism Study; pp. 163–183. DOI

Huong P.T., JiTae K., Giang B.L., Nguyen T.D., Thang P.Q. Novel lanthanum-modified activated carbon derived from pine cone biomass as ecofriendly bio-sorbent for removal of phosphate and nitrate in wastewater. Rendiconti Lincei. 2019;30:637–647. doi: 10.1007/s12210-019-00827-3. DOI

Yagub M.T., Sen T.K., Ang M. Removal of cationic dye methylene blue (MB) from aqueous solution by ground raw and base modified pine cone powder. Environ. Earth Sci. 2013;71:1507–1519. doi: 10.1007/s12665-013-2555-0. DOI

Ouma I.L.A., Naidoo E.B., Ofomaja A.E. An Insight into the Adsorption Mechanism of Hexavalent Chromium onto Magnetic Pine Cone Powder. In: Ramasami P., Gupta Bhowon M., Jhaumeer Laulloo S., Li Kam Wah H., editors. Chemistry for a Clean and Healthy Planet. Springer International Publishing; Cham, Germany: 2019. pp. 185–195. DOI

Pholosi A., Naidoo E.B., Ofomaja A.E. Kinetics and Mechanism of Cr(VI) Adsorption onto NaOH Treated Pine and Mag-netite-Pine Composite. In: Ramasami P., Gupta Bhowon M., Jhaumeer Laulloo S., Li Kam Wah H., editors. Chemistry for a Clean and Healthy Planet. Springer International Publishing; Cham, Germany: 2019. pp. 469–488.

Hussain S., Ghouri A.S., Ahmad A. Pine cone extract as natural coagulant for purification of turbid water. Heliyon. 2019;5:e01420. doi: 10.1016/j.heliyon.2019.e01420. PubMed DOI PMC

Leitch A.E., Armstrong P.B., Chu K.H. Characteristics of dye adsorption by pretreated pine bark adsorbents. Int. J. Environ. Stud. 2006;63:59–66. doi: 10.1080/00207230500523216. DOI

Khokhotva A.P., Khokhotva O. Adsorption of heavy metals by a sorbent based on pine bark. J. Water Chem. Technol. 2010;32:336–340. doi: 10.3103/S1063455X10060044. DOI

Narooie M.R., Afsharnia M., Rahdar S., Baneshi M.M., Ahamadabadi M., Saeidi M., Salimi A., Khaksefidi R. Arsenic Removal from Aqueous Solutions by Raw and Incinerated Pine Bark. J. Glob. Pharma Technol. 2017;9:29–34.

Arim A.L., Neves K., Quina M.J., Gando-Ferreira L.M. Experimental and mathematical modelling of Cr(III) sorption in fixed-bed column using modified pine bark. J. Clean. Prod. 2018;183:272–281. doi: 10.1016/j.jclepro.2018.02.094. DOI

Arim A.L., Quina M.J., Gando-Ferreira L.M. Insights into the Sorption Mechanisms of Cr(III) by Chemically Modified Pine Bark. Chem. Eng. Technol. 2018;41:1378–1389. doi: 10.1002/ceat.201800034. DOI

Khokhotva O.P., Westholm L.J. The impact of surface properties of modified pine bark on the mechanism of sorption of heavy metals from aqueous media. J. Water Chem. Technol. 2017;39:148–154. doi: 10.3103/S1063455X17030055. DOI

Sousa S., Jiménez-Guerrero P., Ruiz A., Ratola N., Alves A. Organochlorine pesticides removal from wastewater by pine bark adsorption after activated sludge treatment. Environ. Technol. 2011;32:673–683. doi: 10.1080/09593330.2010.510535. PubMed DOI

Li Y., Chen B., Zhu L. Enhanced sorption of polycyclic aromatic hydrocarbons from aqueous solution by modified pine bark. Bioresour. Technol. 2010;101:7307–7313. doi: 10.1016/j.biortech.2010.04.088. PubMed DOI

Antunes M.C.G., Pinto S., Braga F.G., Silva J.C.E. Optimisation of bisphenol A removal from water using chemically modified pine bark and almond shell. Chem. Ecol. 2012;28:141–152. doi: 10.1080/02757540.2011.638629. DOI

Paradelo R., Al-Zawahreh K., Barral M.T. Utilization of Composts for Adsorption of Methylene Blue from Aqueous Solutions: Kinetics and Equilibrium Studies. Materials. 2020;13:2179. doi: 10.3390/ma13092179. PubMed DOI PMC

Keränen A., Leiviskä T., Gao B.-Y., Hormi O., Tanskanen J. Preparation of novel anion exchangers from pine sawdust and bark, spruce bark, birch bark and peat for the removal of nitrate. Chem. Eng. Sci. 2013;98:59–68. doi: 10.1016/j.ces.2013.05.007. DOI

Lourie E., Patil V., Gjengedal E. Efficient Purification of Heavy-Metal-Contaminated Water by Microalgae-Activated Pine Bark. Water, Air, Soil Pollut. 2009;210:493–500. doi: 10.1007/s11270-009-0275-6. DOI

Barman S.R., Banerjee P., Das P., Mukhopadhayay A. Urban wood waste as precursor of activated carbon and its subsequent application for adsorption of polyaromatic hydrocarbons. Int. J. Energy Water Resour. 2018;2:1–13. doi: 10.1007/s42108-018-0001-4. DOI

Biswas S., Siddiqi H., Meikap B.C., Sen T.K., Khiadani M. Preparation and Characterization of Raw and Inorganic Acid-Activated Pine Cone Biochar and Its Application in the Removal of Aqueous-Phase Pb2+ Metal Ions by Adsorption. Water Air Soil Pollut. 2019;231:3. doi: 10.1007/s11270-019-4375-7. DOI

Koetlisi K.A., Muchaonyerwa P. Sorption of Selected Heavy Metals with Different Relative Concentrations in Industrial Effluent on Biochar from Human Faecal Products and Pine-Bark. Materials. 2019;12:1768. doi: 10.3390/ma12111768. PubMed DOI PMC

Dawood S., Sen T.K., Phan C. Synthesis and Characterisation of Novel-Activated Carbon from Waste Biomass Pine Cone and Its Application in the Removal of Congo Red Dye from Aqueous Solution by Adsorption. Water Air Soil Pollut. 2013;225:1–16. doi: 10.1007/s11270-013-1818-4. DOI

Hadi M., Samarghandi M.R., McKay G. Simplified Fixed Bed Design Models for the Adsorption of Acid Dyes on Novel Pine Cone Derived Activated Carbon. Water Air Soil Pollut. 2010;218:197–212. doi: 10.1007/s11270-010-0635-2. DOI

Özhan A., Şahin Ö., Küçük M.M., Saka C. Preparation and characterization of activated carbon from pine cone by microwave-induced ZnCl2 activation and its effects on the adsorption of methylene blue. Cellulose. 2014;21:2457–2467. doi: 10.1007/s10570-014-0299-y. DOI

Nurek T., Gendek A., Roman K., Dąbrowska M. The Impact of Fractional Composition on the Mechanical Properties of Agglomerated Logging Residues. Sustainability. 2020;12:6120. doi: 10.3390/su12156120. DOI

Malaťák J., Gendek A., Aniszewska M., Velebil J. Emissions from combustion of renewable solid biofuels from coniferous tree cones. Fuel. 2020;276:118001. doi: 10.1016/j.fuel.2020.118001. DOI

Galhetas M., Lopes H., Freire M., Abelha P., Pinto F., Gulyurtlu I. Characterization, leachability and valorization through combustion of residual chars from gasification of coals with pine. Waste Manag. 2012;32:769–779. doi: 10.1016/j.wasman.2011.08.021. PubMed DOI

Antunes R.A., de Oliveira M.C.L. Corrosion in biomass combustion: A materials selection analysis and its interaction with corrosion mechanisms and mitigation strategies. Corros. Sci. 2013;76:6–26. doi: 10.1016/j.corsci.2013.07.013. DOI

Danraka M.N., Aziz F.N.A.A., Jaafar M.S., Nasir N.M., Abdulrashid S. Application of Wood Waste Ash in Concrete Making: Revisited; Proceedings of the 1st Indo-China Research Series in Geotechnical and Geoenvironmental Engineering; Kuala Lumpur, Malaysia. 25–28 July 2017; New York, NY, USA: Springer International Publishing; 2018. pp. 69–78.

Czech T., Sobczyk T., Jaworek A., Krupa A. Porównanie własności fizycznych popiołów lotnych ze spalania węgla ka-miennego, brunatnego i biomasy; Proceedings of the Conference POL–EMIS; Sienna Czarna Góra, Poland. 13–16 June 2012; pp. 73–82.

Ward J., Rasul M., Bhuiya M. Energy Recovery from Biomass by Fast Pyrolysis. Procedia Eng. 2014;90:669–674. doi: 10.1016/j.proeng.2014.11.791. DOI

Zhang W., Henschel T., Söderlind U., Tran K.-Q., Han X. Thermogravimetric and Online Gas Analysis on various Biomass Fuels. Energy Procedia. 2017;105:162–167. doi: 10.1016/j.egypro.2017.03.296. DOI

Kashin E.M., Safin R.R., Didenko V.N. Generating Gas from Wood Waste as Alternative to Natural Gas in Package Boilers; Proceedings of the International Russian Automation Conference 2019; Sochi, Russia. 8–14 September 2019; pp. 492–500.

PN-G-04571 Solid Fuels—Determination of Carbon, Hydrogen and Nitrogen Content with Automatic Analyzers. Macro Method. Polish Committee for Standardization; Warsaw, Poland: 1998.

PN-G-04584 Solid Fuels—Determination of Total Sulphur and Ash Content with Automatic Analyzers. Polish Committee for Standardization; Warsaw, Poland: 2001.

ISO 18122:2015 Solid Biofuels—Determination of Ash Content. International Organization for Standardization; Geneva, Switzerland: 2015.

Martinka J., Martinka F., Rantuch P., Hrušovský I., Blinová L., Balog K. Calorific value and fire risk of selected fast-growing wood species. J. Therm. Anal. Calorim. 2018;131:899–906. doi: 10.1007/s10973-017-6660-2. DOI

ISO 16967:2015-06 Solid Biofuels—Determination of Major Element—Al, Ca, Fe, Mg, P, K, Si, Na and Ti. International Organi-zation for Standardization; Geneva, Switzerland: 2015.

ISO 16968:2015 Solid Biofuels—Determination of Minor Elements. International Organization for Standardization; Geneva, Switzerland: 2015.

ISO 18125:2017 Solid Biofuels—Determination of Calorific Value. International Organization for Standardization; Geneva, Switzerland: 2017.

Font R., Conesa J.A., Moltó J., Muñoz M. Kinetics of pyrolysis and combustion of pine needles and cones. J. Anal. Appl. Pyrolysis. 2009;85:276–286. doi: 10.1016/j.jaap.2008.11.015. DOI

Brebu M., Ucar S., Vasile C., Yanik J. Co-pyrolysis of pine cone with synthetic polymers. Fuel. 2010;89:1911–1918. doi: 10.1016/j.fuel.2010.01.029. DOI

Butler E., Devlin G., Meier D., McDonnell K. Characterisation of spruce, salix, miscanthus and wheat straw for pyrolysis applications. Bioresour. Technol. 2013;131:202–209. doi: 10.1016/j.biortech.2012.12.013. PubMed DOI

Khalili S., Khoshandam B., Jahanshahi M. A comparative study of CO2 and CH4 adsorption using activated carbon prepared from pine cone by phosphoric acid activation. Korean J. Chem. Eng. 2016;33:2943–2952. doi: 10.1007/s11814-016-0138-y. DOI

Frank C.L., Cox S. The Adaptive Significance of Seed Hoarding by the Mt. Graham Red Squirrel. In: Sanderson H., Koprowski J.L., editors. The Last Refuge of the Mt. Graham Red Squirrel: Ecology of Endangerment. Volume 427. University of Arizona Press; Tucson, AZ, USA: 2009. pp. 256–271.

Aniszewska M., Gendek A., Drożdżek M., Bożym M., Wojdalski J. Physicochemical Properties of Seed Extraction Residues and Their Potential Uses in Energy Production. Rocz. Ochr. Srodowiska. 2017;19:302–334.

Coşkun M. Toxic Metals in the Austrian Pine (Pinus Nigra) Bark in the Thrace Region, Turkey. Environ. Monit. Assess. 2006;121:173–179. doi: 10.1007/s10661-005-9113-5. PubMed DOI

Böhm P., Wolterbeek H., Verburg T., Musílek L. The use of tree bark for environmental pollution monitoring in the Czech Republic. Environ. Pollut. 1998;102:243–250. doi: 10.1016/s0269-7491(98)00082-7. DOI

Sawidis T., Breuste J., Mitrovic M., Pavlovic P., Tsigaridas K. Trees as bioindicator of heavy metal pollution in three European cities. Environ. Pollut. 2011;159:3560–3570. doi: 10.1016/j.envpol.2011.08.008. PubMed DOI

Khan A., De Jong W., Jansens P., Spliethoff H. Biomass combustion in fluidized bed boilers: Potential problems and remedies. Fuel Process. Technol. 2009;90:21–50. doi: 10.1016/j.fuproc.2008.07.012. DOI

Saidur R., Abdelaziz E., Demirbas A., Hossain M., Mekhilef S. A review on biomass as a fuel for boilers. Renew. Sustain. Energy Rev. 2011;15:2262–2289. doi: 10.1016/j.rser.2011.02.015. DOI

Vassilev S.V., Baxter D., Vassileva C.G. An overview of the behaviour of biomass during combustion: Part II. Ash fusion and ash formation mechanisms of biomass types. Fuel. 2014;117:152–183. doi: 10.1016/j.fuel.2013.09.024. DOI

Haykırı-Açma H. Combustion characteristics of different biomass materials. Energy Convers. Manag. 2003;44:155–162. doi: 10.1016/S0196-8904(01)00200-X. DOI

Gendek A., Malaťák J., Velebil J. Effect of harvest method and composition of wood chips on their caloric value and ash content. Sylwan. 2018;162:248–257. doi: 10.26202/sylwan.2017125. DOI

Kistler M., Schmidl C., Padouvas E., Giebl H., Lohninger J., Ellinger R., Bauer H., Puxbaum H. Odor, gaseous and PM10 emissions from small scale combustion of wood types indigenous to Central Europe. Atmos. Environ. 2012;51:86–93. doi: 10.1016/j.atmosenv.2012.01.044. PubMed DOI PMC

Kabata-Pendias A. Trace Elements in Soils and Plants. CRC Press; Boca Raton, FL, USA: 2010.

Ots K., Mandre M. Monitoring of heavy metals uptake and allocation in Pinus sylvestris organs in alkalised soil. Environ. Monit. Assess. 2011;184:4105–4117. doi: 10.1007/s10661-011-2247-8. PubMed DOI

Aboal J., Fernandez J.A., Carballeira A. Oak leaves and pine needles as biomonitors of airborne trace elements pollution. Environ. Exp. Bot. 2004;51:215–225. doi: 10.1016/j.envexpbot.2003.11.003. DOI

Kirchner P., Edwards R., McConnell J.R., Biondi F. Variability of trace metal concentrations in Jeffrey pine (Pinus jeffreyi) tree rings from the Tahoe Basin, California, USA. J. For. Res. 2008;13:347–356. doi: 10.1007/s10310-008-0093-5. DOI

Poikolainen J. Sulphur and Heavy Metal Concentrations in Scots Pine Bark in Northern Finland and the Kola Peninsula. Water Air Soil Pollut. 1997;93:395–408. doi: 10.1007/BF02404769. DOI

Nkongolo K.K., Vaillancourt A., Dobrzeniecka S., Mehes M., Beckett P. Metal Content in Soil and Black Spruce (Picea mariana) Trees in the Sudbury Region (Ontario, Canada): Low Concentration of Arsenic, Cadmium, and Nickel Detected near Smelter Sources. Bull. Environ. Contam. Toxicol. 2007;80:107–111. doi: 10.1007/s00128-007-9325-1. PubMed DOI

Sukhdolgor J., Badamtsetseg S., Adyakhuu D. Chemical Composition and Amount of Macro and Microelements of Pine (Pinus silvestris L.) and Larch (Larix sibirica Ldb) Trees in Mongolia. Mong. J. Biol. Sci. 2003;1:81–83.

BN–89/9103–090—Disposal of Municipal Waste Compost from Urban Waste. Polish Committee for Standardization; Warsaw, Poland: 1989. (In Polish)

Bożym M., Siemiątkowski G. Characterization of composted sewage sludge during the maturation process: A pilot scale study. Environ. Sci. Pollut. Res. 2018;25:34332–34342. doi: 10.1007/s11356-018-3335-x. PubMed DOI PMC

ISO 17225-2:2014 Solid Biofuels—Fuel Specifications and Classes—Part. 2: Graded Wood Pellets. International Organization for Standardization; Geneva, Switzerland: 2014.

ISO 17225-3:2014 Solid Biofuels—Fuel Specifications and Classes—Part. 3: Graded Wood Briquettes. International Organization for Standardization; Geneva, Switzerland: 2014.

ISO 17225-4:2014 Solid Biofuels—Fuel Specifications and Classes—Part. 4: Graded Wood Chips. International Organization for Standardization; Geneva, Switzerland: 2014.

Smolander A., Kitunen V., Paavolainen L. Decomposition of Norway spruce and Scots pine needles: Effects of liming. Plant. Soil. 1996;179:1–7. doi: 10.1007/BF00011636. DOI

Regional wood chip quality parameters decomposition and price linkage with impact on Polish energy sustainability: Time frequency analysis between 2013 and 2019

The Impact of Nutshell Biochar on the Environment as an Alternative Fuel or as a Soil Amendment

Properties of Biochar Derived from Tea Waste as an Alternative Fuel and Its Effect on Phytotoxicity of Seed Germination for Soil Applications

Reducing Emissions from Combustion of Grape Residues in Mixtures with Herbaceous Biomass

Use of Spent Coffee Ground as an Alternative Fuel and Possible Soil Amendment