RU2796037C2 - Method for treatment of lignin sludge - Google Patents

Abstract

FIELD: agriculture; forestry.

SUBSTANCE: invention relates to methods for processing lignin sludge. After dehydration, lignin sludge is biodetoxified using the Gumat-Bio preparation, which is an association of aerobic lignin-cellulose-decomposing microorganisms. At the same time, Gumat-Bio is introduced onto the surface of the sludge-lignin at a dose of 2 liters of solution per 1 m³ of the mass. Then, with an interval of 15 days, this mass is mixed three times. After 1.5 months, the hardening mass is unloaded onto a concrete pad or into a free map, and the technological process of applying the Gumat-Bio preparation is repeated again. Compost ready for recuperation is used as an organomineral fertilizer to increase the fertility of depleted, degraded and sloping lands in the cultivation of crops, shrubs and trees. At the same time, compost is applied at a dose of 60 tons per hectare with its incorporation into the soil to a depth of 15 cm.

EFFECT: biodetoxification of lignin sludge is provided with the possibility of its further use as an organomineral fertilizer.

1 cl, 3 tbl

Description

The invention relates to agriculture and forestry, in particular, to methods for processing lignin sludge.

There are various methods and technologies for processing, detoxification and use of lignin sludge: incineration; incineration and burial; burning and mixing with lime and cement; freezing; its use for aluminum smelting; cement production; building materials; processing and obtaining lime monolith; mixing with a polymer and obtaining a soil mixture used in road construction; creation of vermiculture and vermicomposts; use as an organic additive for forestry reclamation of disturbed lands; obtaining organomineral fertilizer [4, 3, 2, 1, 5, 6, 7].

The main disadvantages of these methods: the elimination of the toxicity of sludge-lignin is not the main goal, the high duration of the technological cycle of waste disposal and processing; high material and energy costs, low socio-economic efficiency.

The closest technical solution, selected as a prototype, is the "Method of processing sludge-lignin" (RF Patent No. 2129533, C02F 11/14, 28.11.1996 [3]).

The disadvantages of the method include the use of chemical reagents for the treatment of lignin sludge, for example, a flocculant and a water repellent.

The objective of the invention is to create a method for biodetoxification of lignin sludge by an association of microorganisms and with the possibility of using it as an organomineral fertilizer.

The essence of the invention is as follows. After dehydration of lignin sludge, biodetoxification is carried out using the Gumat-Bio preparation, representing an association of aerobic lignin-cellulose-decomposing microorganisms. After that, it is used as an organomineral fertilizer. At the same time, Gumat-Bio is applied to the surface of the sludge-lignin stored in storage cards at a dose of 2 liters of solution per 1 m ³ of mass. Then, with an interval of 15 days, this mass is mixed three times. After 1.5 months, the hardening mass is unloaded onto a concrete pad or into a free map, and the technological process of applying the Gumat-Bio preparation is repeated again. The biodetoxification process of lignin sludge composting is carried out in the summer for 3 months. Compost ready for recuperation is used as an organomineral fertilizer to increase the fertility of depleted, degraded and sloping lands in the cultivation of crops, shrubs and trees. At the same time, compost is applied by spreading it on the soil surface at a dose of 60 tons per ha, followed by incorporation of compost into the soil to a depth of 15 cm.

The technical result is due to the fact that in the process of biodetoxification of lignin sludge using the association of aerobic lignin-cellulose-decomposing microorganisms, the pollutants contained in lignin sludge are neutralized, the process of humification of organic substances and the mineralization of macroelements, the resulting compost is used as an organo-mineral fertilizer.

At the same time, compost is applied by spreading it on the soil surface, for example, with a RUM-4 fertilizer spreader, at a dose of 60 tons per hectare, followed by incorporation of compost into the soil with a tillage unit, for example, a K-701 tractor with an LDG-15 cultivator, to a depth of 15 cm .

The proposed method is confirmed by the positive results of the experimental studies, which were as follows.

To conduct stationary experiments, an initial sample of lignin sludge with a low initial content of organic matter in the amount of 2.5 tons was selected from map No. 3 of the Baikal Pulp and Paper Mill (Baikalsk, Irkutsk Region). According to the requirements of GOST R 54651 - 2011 (raw materials for organic fertilizers) an average sample was taken to determine the chemical composition. Sludge-lignin was a dark gray mud-like mass with a moisture content of 79% with a neutral reaction of the environment. The content of total nitrogen (in % of dry matter) was 1.98, phosphorus - 1.1, potassium - 0.14, ash 38%, the ratio of carbon to nitrogen was 7.8 at a rate of 10 (research protocols No. 480, No. 480 /1, No. 481 dated October 30, 2018).

The experimental scheme for studying the ecological efficiency of lignin sludge biodetoxification was as follows:

Option No. 1 - sludge-lignin, dehydrated with a moisture content of 76%;

Option No. 2 - lignin sludge with a moisture content of 90% (water was added to the prototype);

Option No. 3 - sludge-lignin with a moisture content of 76%).

In options 1 and 2, the lignin sludge was placed in two-hundred-liter metal barrels, the sample volume was 0.125 m ³ , the layer thickness was 50 cm. 0.5 l of the Gumat-Bio preparation solution was added to each barrel.

In option 3, Gumat-Bio (dehydrated) with a moisture content of 76% is placed in a wooden box, the layer thickness is 0.25 m, the volume of the sample is 0.75 m ³ , 3 liters of Gumat-Bio are added [7].

In the variants of experience No. 1 and No. 3, dehydrated lignin sludge was used, in option 2 - brought to the initial moisture content (as at the storage site), the experiment was repeated four times.

Within two months, at intervals of once a week, in order to increase aeration, lignin sludge was mixed in barrels and boxes.

The results of the conducted studies are presented in table 1.

After two months, in accordance with the requirements of GOST R 54651-2001, chemical analyzes were carried out (research protocols No. 9, 9/1, 10, 11 of 01/17/2019).

In its original form, before the laying of the experiments, the sludge-lignin was a dark gray mud-like mass with a pungent odor of hydrogen sulfide, methyl mercaptan, and methyl. After two months in the process of composting, the sludge-lignin in option No. 1 and No. 3 was a soil-like structured mass of dark color and an earthy smell with a moisture content of 60%. In the variant of experiment No. 2, in which the lignin sludge was moistened to a moisture content of 90%, organoleptic changes took place with less intensity and for a longer time.

The indicators of the total nitrogen content decreased by 0.2% from the initial (control) value only in option No. 3. The ratio of carbon to nitrogen (C:N) increased in the variants of experience No. 1 and No. 3 (7.9 and 8.4), the content of phosphorus and potassium did not change.

A decrease in the content of chlorides and phenols was noted due to the decomposition of phenolic rings during long-term storage of compost (2 months).

An assessment of the content of the main toxic elements in the compost, which are heavy metals, showed that when using the biodetoxification technology, their content decreased.

According to sanitary, hygienic and veterinary quality indicators, the compost produced on the basis of lignin sludge meets the requirements of GOST R 54651 - 2011. The content of 2CH and DDT isomers was <0.001, with a standard of 0.1 mg/kg.

The specific effective activity of radionuclides was 22.6 Bq/kg at a rate of 300 Bq/kg.

The agro-ecological efficiency of the compost obtained using the lignin sludge biodetoxification technology was assessed. The small-plot experiment scheme included two options: option No. 1 - natural background, (gray forest soil without fertilizers), option No. 2 - background + compost calculation 60 t / ha, area of experimental plots 2 m ² , 6-fold repetition, cultivated in experiments various agricultural crops: sandy sainfoin (Onobrychis arenaria), Tangier rank (Lathyrus tangitanus), eastern sverbiga (Bunias orientalis), buckwheat (Fagopyrum esculentum), narrow-leaved lupine (Lupinus angustifolius), spotted milk thistle (Silybum marianum).

The results of the experiments are presented in tables 2 and 3.

The soil of the experimental plot is gray forest, cultivated, the predecessor is occupied fallow, humus content is 5.6%, acidity is 6.5, the content of nitrate nitrogen is average, phosphorus and potassium are very high and high supply of microelements - copper and zinc is average, manganese - low, gray high. According to ecological and toxicological assessment, mobile forms of heavy metals: lead, cadmium, nickel, cobalt and zinc did not exceed the maximum permissible concentrations (MAC), arsenic - at the level of 1 MAC.

Monitoring of soil fertility indicators and ecological and toxicological assessment of the soil cover were carried out twice, in the spring during the laying of experimental plots and at the end of summer, after harvesting the experimental plants.

After the introduction of compost at a dose of 6 kg/m ² , harrowing and sowing of experimental crops were carried out, sowing was carried out manually, with row spacing of 30 cm on May 30, 2019, seedlings appeared on June 18-21, shoots of sverbiga on June 22-24, harvesting and accounting of green mass held on 15 and 16 August.

Lignin sludge, which is a waste of the pulp and paper industry and is classified as an environmental pollutant (hazard class 3 and 4) as a result of biodetoxification and composting, acquires the properties of an organomineral fertilizer and can be recommended in recovery technologies in the agricultural and forestry sectors of the national economy to increase fertility of depleted, degraded, sloping lands and productivity of cultivated crops, cultivation of trees and shrubs.

Organo-mineral fertilizer obtained as a result of lignin sludge composting with the help of aerobic microorganisms Gumat-Bio [7] has a positive effect on the main indicators of soil fertility and provides an increase in the yield of cultivated crops (from 21% to 46%), as well as their quality. According to the chemical composition and nutritional value, the resulting plant products are classified as biologically safe and can be used in the nutrition and feeding of farm animals. The recommended dose of compost application is 60 t/ha.

Thus, a method for biodetoxification of lignin sludge by the association of aerobic lignin-cellulose-decomposing microorganisms is proposed, the resulting compost is used as an organomineral fertilizer.

Sources of information taken into account:

1. A.S. Shatrov. Investigation of physical and chemical properties of sediments of sludge-lignin of OJSC "Baikal Pulp and Paper Mill" during freezing. / A.S. Shatrova, A.V. Bogdanov, O.L. Kachor // Bulletin of the Irkutsk State Technical University. - 2015. - No. 8. - S. 99-107.

2. Bogdanov A.V. Ecologically safe technology for the processing of accumulated colloidal sediments of sludge-lignin JSC "Baikal Pulp and Paper Mill". / Bogdanov A.V., Shatrova A.S., O.V. Tyukalova, A.I. Shkrabo // News of universities. Applied chemistry and biotechnology. - 2018. - T 8. - No. 3. - S. 126-134.

3. RF patent No. 2129533, C02F 11/14, 11/28/1996. - prototype.

4. M.A. Pashkevich. Assessment of the potential use of lignin sludge for forestry reclamation of disturbed lands. / M.A. Pashkevich, T.A. Petrova, E. Rudzish//Notes of the Mining Institute. - 2019. - No. 235. - S. 106-112.

5. Timofeeva S.S. The current state of surface, underground and waste waters in the zone of influence of sludge reservoirs of the Baikal pulp and paper mill. / Timofeeva S.S., Chemeris N.V., Shenkman B.M. // Modern science-intensive technologies. - 2008. - No. 5 (appendix) - S. 13-19.

6. Patent RU No. 2086521 C1, C05F 11/00.

7. Butyrin M.V. Evaluation of the ecological efficiency of the humic biological product "Gumat-Bio" in the technologies of fermentation and composting of organic waste from pig-breeding complexes / M.V. Butyrin, V.V. Tyumentsev, Sh.K. Khusnidinov, R.V. Zamashchikov, E.I. Ivanova // scientific and practical journal "Bulletin of the IrGSHA", 2022. - No. 5 (112) - P. 16-24. - DOI 10.51215/1999-3765-2022-112-24-35.

Claims (1)

A method for processing lignin sludge, in which lignin sludge is processed in various ways, characterized in that after dehydration, lignin sludge is biodetoxified using the Gumat-Bio preparation, which is an association of aerobic lignin-cellulose-decomposing microorganisms, while on the surface of lignin sludge stored in cards -accumulators, Gumat-Bio is introduced, at a dose of 2 l of solution per 1 m ³ of the mass, then with an interval of 15 days this mass is mixed three times, after 1.5 months the hardening mass is unloaded onto a concrete pad or into a free map and the technological process of applying the Gumat-Bio preparation is repeated once more, the composting process is carried out in the summer season for 3 months, the compost ready for recovery is used as an organomineral fertilizer to increase the fertility of depleted, degraded and sloping lands when cultivating crops, shrubs and trees, while the compost it is applied by spreading it on the soil surface at a dose of 60 tons per ha, followed by incorporation of compost into the soil to a depth of 15 cm.