Resistance of Wood Treated with Iron Compounds against Wood-Destroying Decay and Mould Fungi

Abstract

Treatment of wood with various physical and chemical factors can change the number of wood parameters, which can also lead to changes in resistance to wood-destroying fungi. This study evaluates the effects of hydrothermal treatments (additives Fe2O3 or FeCl3 with and without commercial tannins, also without additives and fresh wood) on decay and mould fungi resistance of modified wood of Scots pine (Pinus sylvestris), Norway spruce (Picea abies), Douglas fir (Pseudotsuga menziesii), walnut (Juglans regia), and Norway maple (Acer platanoides). For wood samples, the resistance against wood decay fungi Trametes versicolor (white rot) and Coniophora puteana (brown rot) and the resistance against mould fungi Aspergillus niger and Penicillium sp. were assessed. The study findings showed that wood modified with iron compounds could cause a higher resistance to wood-destroying fungi. The weight losses of the modified and control wood, caused by T. versicolor and C. puteana, differed for coniferous and deciduous: the average weight loss of treated pine, spruce, and fir wood caused by C. puteana was higher than that caused by T. versicolor, while these differences on maple and walnut wood were not significant. The wood hydrothermal treatment with Fe2Cl3 with and without tannins significantly reduced the weight loss caused by T. versicolor and C. puteana, and the treatment with Fe2O3 slightly improved the decay resistance. For the wood, hydrothermally modified with FeCl3 and FeCl3 + tannins, the mould area for both tested Aspergillus niger and Penicillium sp. was smallest for the wood of all tested tree species compared to other treatments. A different response was obtained for coniferous and deciduous tree species wood. The spruce wood, followed by fir wood, treated with FeCl3 with and without tannins, was the most resistant against the mould fungi. Relatively low resistance against the mould fungi was fixed for the maple wood treated by various iron compounds, except the treatment with Fe2O3 + tannins, which gave a very positive response against the Penicillium sp.

Physical and Chemical Changes in Hydrothermally Modified Wood

“…The wood samples were immersed into the biobased solvents and boiled at a constant temperature of 100 • C in a laboratory pot for 75 h (hereafter, hydrothermal treatment). More specific details about the experiment were provided in Aleinikovas et al (2021) [26].…”

Morphological and molecular features of stain fungi infecting rubberwood (Hevea brasiliensis)

“…For selection process, wood samples made from air dried rubberwood were prepared with size 5×2×0.5 cm and sterilized in an autoclave at 121°C for 15 minutes. Sterile wood samples and mycelium of each stain fungi isolate were put in petri dish (⌀ = 9 cm) and incubated for four weeks (28±2°C, 74.6±5% RH) based on ASTM D 4445-03 (2003) and Aleinikovas et al (2021). Later, the wood samples were removed and dried up at 60°C for three days.…”

Particleboards from Recycled Pallets

“…From the achieved results, it is evident that the kinetic and maximal rating values of the mould growth activity (MGA) on the top surface of PBs was not affected by particles from RSP; on the final (28th) day after inoculation, at least one half of PB surfaces was usually covered with hyphae of moulds, and the average MGA ranged from 3.67 to 4. Generally, surfaces of less durable and chemically unprotected woods and wooden composites are easily accessible to inhabitation by various moulds, mainly in a wet environment [52][53][54].…”