RU2357944C1 - Method of poultry droppings processing - Google Patents

Abstract

FIELD: agriculture.

SUBSTANCE: method of poultry droppings processing involves treating of the droppings with mineral acids. Fresh poultry droppings are mixed with the solution of sulphuric or phosphoric acid; concentration of the sulphuric or phosphoric acid solution amounts to 25-35%, pH values amount to 5.0-6.5.

EFFECT: reducing negative impact on the environment arising from the poultry droppings storage and fertiliser production, decreasing poultry droppings processing time, possibility to process large volume of droppings, reducing end product cost.

Description

The invention relates to agriculture, and in particular to methods of processing animal waste, mainly poultry manure, for the further production of organic fertilizers based on them.

By the order of the Ministry of Natural Resources of the Russian Federation of December 2, 2002, 786 as amended by the order of the Ministry of Natural Resources of the Russian Federation of July 30, 2003 663 “On the Approval of the Federal Classification Catalog of Wastes”, bird droppings are assigned to hazard class 3 and cannot be used as fertilizer without preliminary processing.

One of the main ways of processing bird droppings is its composting. This process, when applying the usual composting method, from fresh litter to the finished product (fertilizer), takes up to 10-16 months or more. When applying the method of accelerated fermentation, it is reduced to 3-4 weeks.

According to patent RU 2207327, a method for processing waste containing fats and proteins is known, comprising oxidizing the waste with oxygen, characterized in that before oxidation the waste is brought to a moisture content of 85-95% to the organic component and alkali is added to pH 12.0-14.0, then heated to a temperature of 160-200 ° C, and the oxidation is carried out by passing an oxygen-containing gas at a pressure of 1.4-2.4 MPa for 0.5-3 hours

The disadvantages of this method are:

- with an increase in the pH of bird droppings of more than 7 units, free ammonia is released, which leads to a loss of nitrogen;

- to prevent emissions of ammonia into the environment, there is a need to use special facilities for its capture;

- the high cost of the final product, because when applying the method, alkali is used, which is an expensive component, and it also becomes necessary to dispose of a large mass of solid waste.

According to the description of the invention to USSR patent No. 871733, the “Method for the production of organic fertilizer” is known, including mixing animal excretions with water, treatment with mineral acids to pH 0.1-2.0, separation of the liquid phase from insoluble solids. As excreta of animals take bird droppings in a mixture with excretions of other animals.

The disadvantages of this method are:

- after completion of the fertilizer production process, it becomes necessary to dispose of insoluble solids, which increases the environmental burden on the environment;

- significant processing time;

- the impossibility of simultaneous processing of large quantities of bird droppings;

- when applying the known method requires the use of special containers that are resistant to harsh acidic environment, and to obtain the desired pH value requires a large amount of acid, which increases the cost of the final product.

The objective of the invention is to remedy these disadvantages, namely:

- reduction of negative environmental impacts arising from the storage of bird droppings and the production of fertilizers;

- reducing the time for processing bird droppings;

- the possibility of processing a large amount of droppings;

- reducing the cost of the final product.

The result is achieved due to the fact that when implementing the method for processing poultry manure, including treating poultry manure with mineral acids, according to the invention, fresh poultry manure is mixed with a solution of sulfuric or phosphoric acid, the concentration of the solution of sulfuric or phosphoric acid is from 25% to 35%, while reach a pH of 5.0 to 6.5.

At the end of processing, fresh bird droppings are ready for use in the technology of producing organic fertilizers, for example, for making mineral additives, including those containing nitrogen, and subsequent granulation.

An acid solution in a concentration of 25% to 35% is used to process fresh bird droppings. When using a lower concentration of acid, the overall humidity of the litter increases, which entails additional energy costs for drying. When applying a higher concentration of acid, the final product has an increased acidity, which can adversely affect soil fertility. Acid in a concentration exceeding 35%, when interacting with an organic substance, partially destroys its easily hydrolyzable fraction, reducing the agronomic value of the fertilizer.

The application of the claimed method for processing poultry manure allows the use of litter mass in the technology for the preparation of organic fertilizers 10-15 minutes after mixing it with an acid solution, for example, to obtain granules from a litter-mineral mixture. In addition, acid-treated droppings can be stored in storage for a long time.

A change in acidity leads to suppression of the activity of pathogenic microflora, i.e. partial disinfection of fresh droppings occurs, which is later used for the preparation of fertilizers.

The use of acid allows you to change the nature and ratio of gases emitted by fresh manure, thereby significantly reducing the environmental burden on the environment by organoleptic indicators.

For the production of fertilizer, the entire litter mass is used. Thus, there is no need to dispose of insoluble solids remaining after fertilizer production, which significantly reduces material costs and environmental burden.

When applying the inventive method, the medium in the mass of litter changes from alkaline to slightly acidic, therefore, the use of special expensive containers that are resistant to a harsh acidic environment is not required, which simplifies the preparation of organic fertilizers and reduces the cost of the final product.

The method in accordance with the invention is as follows.

When using modern methods of keeping birds in cages with automatic climate control, droppings humidity is 60-65%. At the specified humidity, one ton of litter is mixed for 10-15 minutes with 60-53 l of a 25% solution of sulfuric or phosphoric acid or with 40-46 l of a 35% solution of sulfuric or phosphoric acid, while reaching a pH of 5.0 to 6, 5 units

When applying methods for keeping birds without automatically maintaining the climate, the humidity of fresh bird droppings can be from 65 to 80%. When the humidity of the litter is 80%, one ton of the litter for 10-15 minutes is mixed with 30 l of a 25% solution of sulfuric or phosphoric acid or with 23 l of a 35% solution of sulfuric or phosphoric acid, while reaching a pH of 5.0 to 6.5 units .

When the humidity of the litter is 70-75%, one ton of the litter for 10-15 minutes is mixed with 45 or 37 l of a 25% solution of sulfuric or phosphoric acid, or with 35 or 29 l of a 35% solution of sulfuric or phosphoric acid, while reaching a pH 5.0 to 6.5 units

Claims (1)

A method of processing bird droppings, including the treatment of bird droppings with mineral acids, characterized in that the fresh bird droppings are mixed with a solution of sulfuric or phosphoric acid, the concentration of the solution of sulfuric or phosphoric acid is from 25 to 35%, while reaching a pH of 5.0 to 6 ,5.