In this article the review of the methods of lignocellulosic plants

This paper presents results of studies on a new physical-mechanical method of degumming of flax fibers in order to determine optimal parameters of the process for obtaining high-quality fiber.The study was carried out on an experimental device where lengthwise and crosswise flow of the liquid through a straw batch was applied and where the following process parameters were controlled: temperature, flow velocity, and time of the process. The pH was maintained at a stable neutral level. The degumming process was evaluated by measurement of the mass loss of the straw during the process, by physical-chemical tests of the process liquid, by metrological and chemical tests of the obtained fiber, and by statistical analysis of the results. The results of the study, compared with the results of traditional warm water retting, indicate that by proper selection of physical factors of the process, it can be intensified resulting in obtaining high-quality fiber, superior to the fiber obtained in the traditional retting technique.Keywords physical-mechanical degumming of fibrous plants, physical factors, flax fiber, diffusion, lengthwise and crosswise liquid flow, process optimization Bast fibers are enjoying a renaissance because of the development of new applications, which are in accordance with the principles of sustainable growth. The European Technology Platform for the Future of Textiles and Clothing regards bast fibers of flax and hemp as raw materials of special importance for Europe, the so-called ''Textile Flagship for Europe'', that is, a factor that has a strong effect on the attractiveness of the market, with potential to cope with societal and economic challenges of European industry. However, in order to meet the objectives of European Flagship, flax fibers must be characterized with a completely new quality and become an alternative for the fiber obtained in the traditional way. The application of flax fiber in the clothing sector, which makes use of its beneficial effect on physiological parameters of human body, 1,2 and in technical applications as reinforcement for structural composites 3-7 requires high quality that will guarantee obtaining final products with new desired competitive properties. Therefore, it is important to carry out studies on development of a method of obtaining high-quality bast fiber, the quality of which depends on the extraction method, the number of elementary fibers in the stem, distribution structure, and binding of fibers within bundles. Extraction of fibers from the plant relies on degumming of fibrous straw in an aqueous environment where biological, chemical, and physical processes occur. [8][9][10][11] Currently, a method commonly used in central Europe of separating ligneous parts of stems from fibers, extracting them and removing the non-cellulosic Downloaded from residues is the so-called dew retting, that is, retting of the fibrous plants on the fields. The retting process involves spreading the straw on the ground, where it is subjected to moisture and later to microbi...

SummaryIn the cultivation of horticultural plants in greenhouses the most commonly used substrate is rockwool, while organic substrates are used in an unprocessed state. Cultivation in organic substrates, after they have been suitably processed, also makes it possible to obtain high yields at levels similar to those in rockwool cultures. Fibrous organic substrates, due to the wide C:N ratio, are characterized by high biological sorption towards nitrogen, causing N deficiency during the initial period of plant growth. In 2007-2009, a study was conducted, the aim of which was to determine the effect of nitration of fibrous organic substrates (sawdust, rye straw, flax shives) with nitric acid on nitrogen availability and the yields produced by tomato plants. The process of nitration of the organic substrates was carried out with the use of 10% HNO 3 . The appropriate pH of the substrates after the process of nitration was obtained by washing the substrates with water. As a result of nitration the levels of nitrogen fixed in lignin compounds and simpler polysaccharides increased to about 2%. Nitration of the organic substrates increased nitrogen availability to plants in the first five weeks of culture. Subsequently, the N-NO 3 content in the nutrient solution collected from the nitrated substrates was at the same level as for the nonnitrated substrates. The yields produced by tomato plants depended on both the nature of the substrate and whether or not it had been nitrated with nitric acid. The most useful organic substrate for soilless culture, retaining good structure during the growing period, was the substrate of sawdust. The substrate of straw was found to undergo quick biodegradation, therefore its usefulness for soilless culture was low. The highest yield of tomato was obtained from the cultures on rockwool and on the nitrated sawdust substrate; the lowest yield was produced on the straw substrate.

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