CS264824B1 - Organic lignocellulosic fertilizer - Google Patents

Abstract

Organic lignocellulosic fertilizer is produced from sludge sewage treatment plants containing waste cellulosic and lignocellulosic fibers, tree corol and urea or other nitrogen containing substances. The conversion of lignocellulosic materials to the desired fertilizer is achieved by the biological process taking place in the so-called fertilizer. bioreactors in which the material is simultaneously hygienized. After leaving the bioreactor, the material matures in heaps for 3 to 5 weeks. Organic lignocellulosic fertilizer improves soil structure and enriches it with humus-forming substances. According to customers' requirements, it can also be enriched with some trace elements. The solution can be used in the pulp and paper industry, in the plant with more fiber waste. The product will be used in agricultural large-scale production as well as small-scale production.

Description

The present invention relates to an organic lignocellulosic fertilizer made from non-traditional, previously unused materials - waste cellulosic and lignocellulosic fibers.

In the manufacture of cellulose and paper, as well as in the treatment of recovered paper, a relatively large number of different cellulosic and lignocellulosic wastes are produced. Among these, a large proportion are short cellulosic fibers, which are generally unusable for papermaking and which pass through sewn paper machines. A relatively large amount of such short cellulosic fibers is formed in the processing of recovered paper. Said short cellulosic fibers are discharged into waste conduits. Xch discharges into natural religents are considerably limited. For this reason, they must be trapped, usually in mechanical waste treatment plants. Sludges from sewage treatment plants containing short cellulose fibers are dewatered and in this form are practically exported to landfills where they are ecologically defective because they occupy useful areas and are subject to biodegradation accompanied by often unpleasant odors.

From the chemical point of view, waste cellulose fibers can be considered as a source of organically incorporated carbon, i. as a valuable secondary raw material. Several methods have been proposed to utilize this material. They were considered to be directly converted to protein bovmata used as animal feed via the microbial culture of Chaetomium cellulolyticum (Waterloo-M. Moo-Young, A. Ling, DG McDonald: Pulp and Paper Canada 81, T 123 ( 1980), as well as direct feeding to livestock after heat treatment and the possible addition of urea to increase nutritional value in ruminant fattening (tax procedure STAKE - Compagnie Frangaise d'Edeses et de Construction Technic: Corporate promotional materials). realized and currently exist only in pilot scale.

If the short cellulosic fibers contain a greater amount of kaolin paper filler, they can be burned in a special process, regenerating the papermaking kaolin (the so-called ZIMPRO-U FENCHEL process: Deutche Papierwirtschaft No. 3, 129 (1978) and U.). Fenchel: Das Papier 32 (No. 10A) V 34 (1978) However, this process has proved to be economically demanding.

Combustion of this material due to its high humidity is also unsuitable and requires additional fuel.

There are also suggestions in the literature for adding cellulose fibers (in the form of sludge from sewage treatment plants) to the soil where they should serve as organic fertilizer (A.Z. Jevilevič: Use of sludge from waste wastes, SNTL Prague 1984). However, this process has the disadvantage of relatively long humification of the cellulosic fibers, and therefore it is preferable to undergo a biological treatment in which their letters are converted to agriculturally valuable organic substances more rapidly.

However, the simple composting of sludges made of short cellulose fibers is practically impossible, since it is a compact, mechanically significant solid material which is not easy to aerate either by mechanical aeration or by the introduction of compressed air. Successful composting is also prevented by the high water content. For this reason, it is necessary to add to the cellulose fibers a material capable of extracting excess moisture and to impart mechanical properties to the blends allowing the desired biological processes to proceed. In terms of occurrence in pulp and paper industry, the most suitable for this purpose is tree bark, which is waste in pulp mills, with problematic possibilities of use. Its use by combustion in special boilers is not an optimal solution in all cases.

However, material with similar properties, such as sawdust, straw garbage and the like, can also be used instead of bark.

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In places with a large concentration of bark waste, it is economically interesting to compost the bark itself, possibly with the addition of biocal or dome waste (Prospect materials of CAP Stětí), which requires its mechanical treatment, mainly by grinding. However, such processing of the cortex itself does not solve the problem of other paper waste. In view of the complex treatment of waste materials and thus the implementation of waste-free technology in the production of pulp and paper, it is therefore desirable to treat the cortex with other separately unusable materials.

the role of the bark (or sawdust) in composting sludges consisting of short cellulose fibers is different than in composting biocal (i.e. sludge from biological waste water treatment plants containing mainly cells of propagated microorganisms) or other carbon-poor material.

In this case, the cortex acts as a so-called. a carbon carrier without which the life of microorganisms causing humification is not possible.

In the composting of cellulosic materials, the bark is not required as a carbon carrier, since the cellulose (or lignin itself) contains sufficient carbon, but in this case it is necessary as a material conditioning agent to allow the composting process to proceed successfully.

In order to successfully carry out the biological process, which results in organic fertilizer, it is necessary to keep the proportion of carbon and nitrogen content in the processed material. However, neither the bark nor the sludges containing cellulose fibers are virtually free of nitrogen, and it is therefore necessary to add nitrogen to the zirconium in the form of a sophisticated nitrogen compound or in the form of agricultural nitrogenous wastes such as manure.

Conventional composting in heaps is a process demanding in terms of area and labor, and it is therefore advantageous to carry out the whole process in a special facility, the so-called. bioreactor.

The bioreactor is a continuous tunnel or tower device through which the material to be processed passes under intensive aeration.

Bioreactors are currently used to treat agricultural and municipal waste. They have not been used to process garbage from the pulp and paper industry so far.

This way of use will require some modifications of their current construction. The product obtained contains 50-60% dry matter and 14-20% ash and 37-45% carbon in dry matter.

The present invention is based on an organic lignocellulosic fertilizer. The raw materials for its production are waste water sludges from the pulp and paper industry. The fertilizer contains 54 to 66% by weight. sludge consisting of cellulose fibers with a dry matter content of 20 to 25% by weight; _t 33-44% by weight. tree bark and / or sawdust with a dry matter content of 55 to 70% by weight; and 1 to 2 wt. urea or equivalent amount of other nitrogenous substance.

The waste water sludge used to produce this fertilizer contains 10 to 20% ash, 30 to 45% carbon and other constituents (hydrogen, oxygen) in the dry matter.

The organic lignocellulose fertilizer does not contain free ammoniacal nitrogen and is suitable for improving the content of its humus-forming component.

Examples:

1. 15.6 t a.s. The short fibers (sewage sludge containing waste cellulosic fibers) are mixed with 9.6 t a.s. after dewatering on a double sieve press or other suitable device. cortex and 0.5 t a.s. of crystalline urea and are metered into a bioreactor.

Before entering the bioreactor, the dry matter is adjusted to 40% by adding the finished product exiting the bioreactor, thereby simultaneously enriching the material with the necessary microflora. Upon exit from the bioreactor, the material is stacked on maturing piles where it is stored for 3 to 4 weeks. The mature product is shipped by means of mass freight transport, for small growers it is filled into small-scale packaging.

2. 12.5 t a.s. Short fibers (sewage sludge containing waste cellulose fibers) are mixed with 7.7 t a.s. after dewatering. wood sawdust and 4.6 t a.s. slurry. After adjusting the dry matter to 40% with the finished product, the material is fed into the bioreactor and proceeded further as in Example 1. Bark and sawdust are interchangeable materials, a mixture thereof may also be used. The product can be enriched according to customer requirements with the microelements necessary for the growth of agricultural crops.

3. Lignocellulosic organic fuels in quantities necessary for verification of efficacy and safety may also be prepared in a suitable laboratory equipment. Examination of samples prepared at authorized agricultural workplaces confirmed that lignocellulosic fertilizer can be qualified as an organic substrate with the addition of mineral nutrients.

The nitrogen added during the process is partially mineralized and partially immobilized into organic bonds as a result of the gradual conversion of the organic substances of the processed raw materials. The biochemical evaluation shows that the material exhibits moderately high basal respiration with the ability to convert contained organic substances into substances with higher stability. The selected substrate composition and method of production makes it possible to produce organic fertilizer resp. growing substrate corresponding to quality characteristics at least according to ČSN 46 5735.

The advantage of the proposed process compared to conventional composted is the possibility to process wastes of pulp and paper industry directly on the place of their generation, without large space requirements and without higher labor requirements. The organic fertilizer produced is usually applied in the immediate vicinity of the production plants, thus saving transport costs.

Claims (2)

1. An organic lignocellulosic fertilizer based on sewage sludge from the pulp and paper industry, characterized in that it contains 54 to 66% by weight. sludge consisting of cellulose and lignocellulosic fibers having a pulp content of 20 to 25 wt.%, 33 to 44 wt. tree bark and / or sawdust with a pulp content of 55 to 70 wt. and 1 to 2% urea or equivalent amount of another nitrogenous substance. 2. The organic lignocellulosic fertilizer according to claim 1, characterized in that the sludge formed from the cellulose and lignocellulosic fibers contains, in the dry matter, 10 to 20% by weight of the dry matter. ash and 30-45% carbon.