HU219774B - Method for recycling of dangerous animal wastes - Google Patents

Abstract

The characteristic of the method according to the invention is that the animal waste is collected, before disposal it is reduced to a size of at least 50 mm and homogenized, and its dry matter content is set to a value between 15-75%, then - if desired - it is pre-treated with protolytic enzymes, and then the waste is disposed of in a closed space - if necessary after pre-heating – It is heat-treated at a temperature of 100–180 °C and an overpressure of 2–3 bar for a period of 20–60 minutes, then the mixture is placed in a heat-insulated container to rest and its dry matter content is adjusted to the value required for utilization by dewatering, the aqueous phase is degreased if necessary, and the dehydrated waste – if necessary, the waste After adjusting its pH to a value between 8-10 with lime-containing material and mixing in additional additives, it is extracted for utilization. ŕ

Description

The present invention relates to a process for the disposal and recovery of animal waste (ruminant, stomach and intestinal contents, sewage sludge, hair, etc.) which is hazardous waste and which cannot be utilized as feed material or due to legal requirements.

In Hungary and around the world, the disposal and recovery of large quantities of animal waste, which cannot be used as feed, in slaughterhouses and in animal processing plants is a problem. The amount of this in Hungary is hundreds of thousands of cubic meters.

The regulatory environment in all countries with legislation harmonizing with the European Union is such that it requires the controlled treatment and disposal of this waste. Therefore, technologies for treating similar waste are being addressed around the world.

The processing of by-products from meat processing plants is described, for example, in U.S. Patent No. 4,234,567, in which the by-product is reduced to feed after the addition of fibrous plants and stabilizers and preservatives.

This solution is not suitable for processing by-products which cannot be processed into feed.

DE 3,124,322 describes the disposal of such infectious by-products by the addition of formaldehyde. This solution does not allow the recovery of the by-product.

The treatment of dead animals is described in HU 174,014, wherein the waste is treated in a cauldron at a pressure of 3-4 att for 1 to 3 hours and the resulting mixture is referred to a feed mixture. This solution also does not allow the complex processing of waste.

The aim of the present invention was to develop a technology line that would allow the disposal and recovery of hazardous animal waste which could not be used as feed due to both quality and regulatory requirements.

Based on the above, the subject matter of the application is a process for the disposal and recovery of animal waste which is hazardous waste, which cannot be used as feed, characterized in that the animal waste is collected, crushed and homogenized to a size of at least 50 mm and has a dry matter content of 15-75%. and, if necessary, pretreatment with protolytic enzymes followed by heat treatment in an enclosed space, optionally after preheating at 100-180 ° C, overpressure of 2-3 bar for 20-60 minutes, and allowing the mixture to cool in a heat-insulated container. and the dry matter content is adjusted to the value required for recovery by dewatering, the aqueous phase is optionally degreased, and the dewatered waste is optionally adjusted to pH 8-10 with lime-containing material. after adjustment and mixing of additional additives - for recovery.

In the process, it is advantageous if the dry matter content of the waste is adjusted to 12-20% for recovery by injection into the soil.

It is also advantageous in the process to adjust the dry matter content of the waste to 25-60% for recovery by composting.

It is also advantageous to adjust the dry solids content of the waste to 25-60% by spraying the mixture to the soil.

The technology starts with the reception of hazardous waste, for which purpose a closed technological chain has to be provided for various forms of transport (container, suction wagon). This requires 30-100 cubic meters of usable volume, depending on the capacity planned.

After that, the piece waste is shredded.

If necessary, the shredded waste, in particular highly contaminated fats, is pre-treated with a microbiological method.

The essence of the treatment is an enzymatic process by which the structure of the infectious agents is disintegrated, the surface structure of the infectious microorganisms is disrupted, so that even at a lower amount of heat, the bio-system is destroyed.

The biological treatment takes place in the aqueous phase, so it is possible to continuously control the amount of both additives and trace elements and to control the process.

The treated portion of the waste can be preheated with treated waste on setback to increase energy efficiency.

The heat treatment of the waste can be realized primarily in batch operation equipment, but also in continuous operation equipment.

The process of the invention will be described in more detail by the following example.

Example

The waste received at the receiving station consisted of sewage sludge, a mixture of rumen, stomach and intestine.

The consistency of the waste did not make crushing necessary.

The waste was microbiologically pretreated with a mixture of protolytic enzymes at a concentration of 4.2 liters / cubic meter (200 mg / l). The pH of the enzyme mixture was 5.2.

The waste was then heat treated in an autoclave at 140 [deg.] C. and a pressure of 3 bar, and then transferred to a 25 cubic meter cooling tank.

After one hour of rest, the waste was mechanically dewatered to a dry matter content of 20%.

The results of the microbiological examination of the treated waste are shown in Table 1.

Table 1

Parameter unit qualification Faecal colic number / 4 χ 1 gram negative Streptococcus faecalis number / 4 χ 1 gram negative Salmonella sp. pos./2 χ 10 grams negative

HU 219 774 Β

Table 1 (continued)

Parameter unit qualification Human parasitic helminth cancer number / 100 grams negative Dry matter content 1 g wet weight 0.2043 g

It can be seen that the waste that has undergone the treatment according to the invention has been properly disposed of and there is no obstacle to recovery.

The treated waste was recovered by injection into soil after adjusting its pH to 8 with lime dosing.

Advantages of the present invention:

- proper microbiological disposal of hazardous waste,

- simple energy saving procedure,

- Multiple use potential.

Claims (4)

PATIENT INDIVIDUAL POINTS 1. A method of disposing of and disposing of animal waste that is considered to be hazardous waste and is not usable as feed, comprising collecting animal waste, comminuting and homogenizing at least 50 mm before disposal, and adjusting the dry matter content to 15-75%. and, if desired, pretreated with protolytic enzymes, and then treat the waste in a closed space, optionally after preheating at 100-180 ° C, for 2-3 bar over a period of 20 to 60 minutes, then transferring the mixture to a thermally insulated container to rest and dry matter. dewatered to the value required for recovery, the aqueous phase optionally degreased, and the dewatered waste, optionally with a pH of between 8 and 10 with the lime content, and auxiliary additive after mixing of materials - recovery. Method according to claim 1, characterized in that the dry matter content of the waste is adjusted to between 12 and 20% for use in the injection of the mixture into the soil. 3. A process according to claim 1, wherein the dry matter content of the waste is set at between 25 and 60% for use in composting. The method according to claim 1, wherein the dry matter content of the waste is adjusted to 25-60% by spraying onto the soil.