RU2445297C1 - Method of producing organic fertiliser from wastewater sludge - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to ecology and can be used in recycling wastewater sludge formed at city aeration stations. The method involves mixing wastewater sludge with storage life of less than 3 years with turf in volume ratio of 0.5:0.5 or 0.6:0.4, respectively. The obtained mixture undergoes aerobic composting in the presence of a biological activator in amount of not less than 15% of the volume of the compost mixture. The biological activator used in the compost mass is inoculating compost based on poultry droppings and microbial strains Bacillus subtilis B-168, Bacillus mycoides B-691, Streptomyces sp. Ac-154, Mukor psychrophilus F-1441, Candida utilis Y-2441 in amount of 1·10⁶-1·10⁷ cells per millilitre per ton of poultry droppings.

EFFECT: shorter composting time.

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Description

The invention relates to the field of ecology and can be used in the disposal of sewage sludge generated at urban aeration stations.

The invention relates to the field of agriculture, to agricultural chemistry, in particular to biologically active organic fertilizers containing organic matter, nitrogen, phosphorus, potassium, calcium, magnesium, trace elements, phosphate-mobilizing microorganisms.

The problem of protecting water bodies from pollution and wastewater treatment leads to large-scale accumulation of sludge, or sewage sludge, which can become a source of secondary environmental pollution.

Precipitation of urban wastewater (WWS) has a high fertilizer value, because contain a large number of nutrients necessary for the growth and development of plants. To date, considerable experience has been gained on the use of WWS as organic fertilizers, see Ivanov I.A., Ivanova I.O., Kravchuk V.I. et al. On the possibility of using urban sewage sludge as an organic fertilizer // Agrochemistry. - 1996. - No. 3. - S.85-92; Ubugunov L.L., Doroshkevich S.G., Mangataev Ts.D. Ecological and agrochemical effectiveness of urban sewage sludge and zeolite-containing tuffs. - Ulan-Ude: Publishing House of the Buryat Scientific Center of the SB RAS, 2001. - 140 p.

There is a known method of producing fertilizer by methane fermentation, in which the substrate is heated to boiling, ammonium carbonate is distilled from it to a residual content of less than 250 mg / l, then the hot substrate is calcified by adding 1-20 g / l CaO with the simultaneous removal of ammonia liberated, saturated with sludge gas obtained by methane fermentation to a final alkalinity of 0.01-1.5 g / l, and the precipitate obtained is separated from the water by mechanical separation, see SU Copyright certificate No. 998452, IPC 3 C05F 3/00, C05F 7/00 1983.

The disadvantages of this method is the complexity of the process of obtaining fertilizer and the need for additional expensive equipment.

A known method of processing multicomponent liquid waste, for example municipal waste, comprising mixing liquid waste with a binder and then burying the resulting mixture, in which shale ash is used as a binder with an average particle diameter of not more than 80 μm, with a ratio of the volumes of ash and the processed liquid waste not less than 0.75. The preferred embodiment, when the resulting mixture is kept until curing for at least 240 hours, see Patent RU 2155738, IPC 7 C05F 3/00, C05F 7/00, C02F 1/52, B09B 1/00, 2000.

The disadvantages of this method is the increase in waste and the burial of the resulting mixture, which requires the allocation of additional land for burial.

The closest in technical essence is a method for producing organic fertilizer from sewage sludge, including mixing sewage sludge with an organic component and subsequent aerobic composting of the resulting mixture, as a sewage sludge use fresh dehydrated sewage sludge with a shelf life of less than 3 years, and as organic component using beer grains, or sawdust, or peat in the following volumetric ratio, respectively 0.5: 0.5 or 0.6: 0.4 with the addition of a bioactivator in the form of a compo tnoj sourdough prepared on spent grains in an amount not less than 15% of the composted mixture, and after the natural drying is carried composting the compost cm. Patent RU 2,299,872, the 4th embodiment, 8 of the IPC C05F 7/00, 2007.

The disadvantages of this method are the duration of composting, 4 months.

The objective of the invention is to reduce composting time.

The technical problem is solved by a method of producing organic fertilizer from sewage sludge, including mixing sewage sludge with a shelf life of less than 3 years with peat in a volume ratio of 0.5: 0.5 or 0.6: 0.4, respectively, followed by aerobic composting of the resulting mixture in the presence of a bioactivator in an amount of not less than 15% of the volume of the compostable mixture, in which seed compost based on bird droppings and strains of microorganisms Bacillus subtilis B-168, Bacillus mycoides B-691, Streptomyces sp. is introduced into the compostable mass as a bioactivator. Ac-154, Mukor psychrophilus F-1441, Candida utilis Y-2441 in the amount of 1 · 10 ⁶ -1 · 10 ⁷ cells in 1 ml per 1 ton of bird droppings.

The solution to the technical problem reduces the composting time.

A method of producing organic fertilizer from sewage sludge is shown in the examples.

Prototype Example

The method of producing organic fertilizer according to option 4 is as follows. Sewage sludge from storage sites with a shelf life of less than 3 years and dehydrated sludge directly from sludge cards (organic content ≥15-30%) are dried to a moisture content of 40-45% and mixed with beer pellet in a volume ratio of 0.5: 0.5, respectively or 0.6: 0.4 with the addition of a bioactivator in an amount of at least 15% of the mixture in the form of compost starter prepared on a beer pellet by cultivating a consortium of microorganisms on it, the following microorganisms are used as a consortium: Aspergillus niger, Aspergillus oryzae Asper gillus sydowii, Cephalosporium, Glyocladium Cda., Trichoderma sp., actinomycetes Streptomyces griseus, Streptomyces termoviolaceus, Streptomyces globisporus, Streptomyces ruber, Streptomyces viridosporus, and Bacillus subtus mycoides, Bacillus subtilis mycoides

The mixture is laid in 100 m collars on a concrete site and composted for 4 months when the temperature of the mixture is increased to 45 ° C and periodically mixed to aerate the substrate and evaporate excess moisture. At the end of the process, compost is dried under natural conditions. Ready compost meets the requirements of GOST for all standardized indicators.

According to the claimed object, the method of producing organic fertilizer is as follows. Sewage sludge from storage sites with a shelf life of less than 3 years and dehydrated sludge directly from sludge cards are dried to a moisture content of 40-45% and mixed with peat in a volume ratio of 0.5: 0.5, respectively, with the addition of bioactivator in an amount of at least 15% of volume of compostable mixture. A bioactivator is a compost obtained by adding to the bird droppings of a consortium of microorganism strains Bacillus subtilis B-168, Bacillus mycoides B-691, Streptomyces sp. Ac-154, Mukor psychrophilus F-1441, Candida utilis Y-2441 in the amount of 1 · 10 ⁶ -1 · 10 ⁷ cells in 1 ml per 1 ton of bird droppings in the periodic mixing mode.

The strains that make up the consortium of microorganisms: Bacillus subtilis B-168, Bacillus mycoides B-691, Streptomyces sp. Ac-154, Mukor psychrophilus F-1441, Candida utilis Y-2441, see the All-Union Collection of Microorganisms "Collection of Cultures of Microorganisms", State Reseach Center of Virology and Biotechnology "Vector".

On the basis of a consortium of microorganisms, a microbiological community of seed compost is formed, which is provided with easily accessible substrates of food for microorganisms and adapted in terms of composition to the conditions of composting technology.

Aerobic composting of the obtained mixture of sewage sludge and peat in the presence of a bioactivator in an amount of 15% is composted in the piles for 1 month with periodic stirring to aerate the substrate and evaporate excess moisture. The process proceeds with an increase in the temperature of the mixture to 45 ° C. At the end of the process, compost is dried under natural conditions. Ready compost meets the requirements of GOST for all standardized indicators.

Example 1

Sewage sludge from storage sites with a shelf life of less than 3 years and dehydrated sludge directly from sludge cards are dried to a moisture content of 40-45% and mixed with peat in a volume ratio of 0.6: 0.4, respectively, with the addition of bioactivator in an amount of at least 15% of volume of compostable mixture. The bioactivator is a seed compost based on bird droppings and a consortium of microorganism strains Bacillus subtilis B-168, Bacillus mycoides B-691, Streptomyces sp. Ac-154, Mukor psychrophilus F-1441, Candida utilis Y-2441 in the amount of 1 · 10 ⁷ cells in 1 ml per 1 ton of bird droppings in the periodic mixing mode.

Aerobic composting of the resulting mixture of sewage and peat sludge in the presence of the specified bioactivator in the amount of 15% of the volume of the compostable mixture is composted in collars for 1 month with periodic stirring to aerate the substrate and evaporate excess moisture. The process proceeds with an increase in the temperature of the mixture to 45 ° C. At the end of the process, the biocompost is dried in vivo. Ready biocompost meets the requirements of GOST for all standardized indicators and can be used as organic fertilizer.

Example 2 is similar to example 1.

Aerobic composting of the obtained mixture of sewage sludge and peat in the presence of the specified bioactivator in an amount of 20% of the volume of the compostable mixture is composted in collars for 1 month with periodic stirring to aerate the substrate and evaporate excess moisture.

Example 3 is similar to example 1.

As bioactivator, seed compost based on bird droppings and a consortium of microorganism strains Bacillus subtilis B-168, Bacillus mycoides B-691, Streptomyces sp. Ac-154, Mukor psychrophilus F-1441, Candida utilis Y-2441 in the amount of 1 · 10 ⁶ cells in 1 ml per 1 ton of bird droppings.

Sanitary-parasitological and sanitary-bacteriological indicators of compost are presented in the table.

Table Sanitary-parasitological and sanitary-bacteriological indicators of compost No. sample and depth of selection Helminth eggs, ind./kg Cysts of pathogenic protozoa, ind./kg Pathogenic microorganisms, including salmonella cells / g BGKP, cells / g 1 (0-10 cm) 0 0 0 <10 ² 2 (10-50 cm) 0 0 0 <10 ²

Thus, the claimed method allows to reduce the time to obtain high-quality organic fertilizer from sewage sludge 4 times in comparison with the prototype.

Claims (1)

A method for producing organic fertilizer from sewage sludge, comprising mixing sewage sludge with a shelf life of less than 3 years with peat at a volume ratio of 0.5: 0.5 or 0.6: 0.4, respectively, followed by aerobic composting of the resulting mixture in the presence of a bioactivator in not less than 15% of the volume of the compostable mixture, characterized in that seed compost based on bird droppings and microorganism strains Bacillus subtilis B-168, Bacillus mycoides B-691, Streptomyces sp. is introduced into the compostable mass as a bioactivator. Ac-154, Mukor psychrophilus F-1441, Candida utilis Y-2441 in the amount of 1 · 10 ⁶ -1 · 10 ⁷ cells in 1 ml per 1 ton of bird droppings.