Abstract:
This work has the purpose of emphasizing some methods of studying
and testing the biodegradation of some lignocellulose composite structures
represented by some fir and beech test pieces. The test pieces made of fir
wood have the size (7.5x3.0x1.5) cm and a relative equilibrium humidity
Ur=13.63%, those made of beech wood have the size (8.5x4.3x1.5) cm and a
relative equilibrium humidity Ur=14.74%. They were used both in their
natural state (the reference sample) and chemically treated, in which case
they have undergone a treatment of impregnation. The treatment has been
carried out through impregnation by brushing in both ways
. There were used
5 chemical bioprotecting substances (biocides). These chemical substances
were used in different concentrations (1%, 3%, and 5%) and they are both
organic and inorganic. Therefore, the treatment of the wooden test pieces
was achieved with unmodified/modified straw lignin rendered soluble in
ammonia solution 0.1 N, furan resin dissolved in distilled water, copper
chloride and copper ammonia solution. Before c1arrying out the treatment,
the test pieces made of fir and beech wood have been weighed with a
precision of 0.01g. After carrying out the impregnation and after drying at
atmospheric humidity, the test pieces made of fir and beech wood have
undergone once again the process of weighing in order to establish the mass
of the test pieces after the application of the chemical treatment. As a result
of this undertaking, both the treated and the untreated (reference samples)
test pieces made of fir and beech wood have undergone various tests of
biodegradability. The process of biodegradation was analyzed from the point
of view of several ways of testing it. Their choice was made starting from the
standard biological risk classes with regard to the biological attack. The
testing of the level of biodegradation and implicitly the level of bio-
protection was achieved in various environments, namely: in indoor
environment (laboratory conditions), in outdoor environment (outside the
laboratory), in soil (in the absence of plants) and in soil in the presence of
the bean plants,( the Vera breed). As a result of these tests there could be
noticed that the treatment applied on the surface of the woody material is
effective (the highest level of biodegradability is registered at the reference
samples).
