DE19502504A1 - Prodn. of soil improver from composted refuse or landfill material - Google Patents

Abstract

Process comprises producing a 'recycling substrate' from composted refuse or material from landfill sites with a particle size of up to 20 mm, by (a) removing salts by leaching and (b) opt. any pollutants are converted to humus, degraded and/or immobilised by addn. of organic and inorganic additives followed by incubation. Also claimed is the process as above where step (a) is omitted.

Description

The problem of disposing of ever growing trash the municipalities and private waste disposal companies in the Bun Republic and other countries face serious problems. By the principles of avoiding and recycling waste tries to reduce the amount of waste and appropriate recycling to develop opportunities. Fall next to household waste in large quantities of commercial waste as well as rubble and soil start. Regarding household waste, one becomes economical and eco logically meaningful utilization particularly difficult because a mixture of different types of waste in household waste lies. Through separate collection of recyclables and bio waste len these components can already be used well the. There remains a residual waste fraction, which is after must be disposed of in a residual waste disposal site.

As a pretreatment of this residual waste fraction, in addition to the thermal treatment various "cold" pretreatment procedure on the market. Here, the residual waste is by Kom Position aerobically or pre-treated by fermentation anaerobically. As a result, the easily degradable organic substance is lost met. The availability of elutable substances and harm substances should be reduced.  

The latest developments separate the residual waste in front of the compost again in one or more light fractions and one or several heavy fractions. The light fraction can be found under Um be used thermally, the heavy fraction has to long pretreated and deposited "cold". In this way For a large volume, it must still be more expensive and ecological A non-harmless landfill room built and maintained become. Considering the mass flows in the megaton range nationwide investments of many billion DM necessary.

The procedures just outlined and their problem areas are very new and are z. T. still in the research stage. So far, they have not been used across the board. Until in rather, the seventies became household waste wild tipping uncontrollably deposited. Since the beginning of the "orderly" landfills were created in the 1970s are often largely filled in today, but in many cases as so-called old deposits, massive ecological and ge pose health problems. Also here are renovation and Consequential costs in the high billions have been calculated.

On the other hand, old landfill is already considered "Raw material deposits" seen. In the course of the landfill dismantling are already deposited landfill areas in model tests boxed again and the boxed material separated and recycled in individual fractions. As the largest faction with a volume share of approx. 50%, however, an earth remains like fine grain fraction, for which no recycling so far  opportunities exist. This group must in turn de are posed and thus claims expensive and scarce depo no room.

In the following a method is described with which it is ge succeeds in both the heavy substance fraction from pre-rotten rest garbage (fine grain) as well as the fine grain fraction from the depo treatment of kidney demolition so that it can be used as a building material and as a re cultivation substrate can be recycled. The procedure Ren thus makes it possible to dismantle landfills and store them massive savings in landfill volume. On the In this way, scarce landfill areas are protected and stand for a much longer period of time. Simultaneously The requirements of the Waste Act and the cycle apply economic law and ecological demands regarding extensive recycling of residual materials is sufficient done.

The innovative process works according to the following principle. Trashed landfill material is processed according to the state of Tech nik separated and a sieve fraction with grain size up to about 0-30 mm won. We prefer to process grain sizes of 0-6 mm or 0-10 mm. For larger grain sizes an op table purity of the material with regard to typical waste components are respected.

It can also remove pre-rotted waste in the same way to be screened. The structure made many structures  organic components destroyed, so that the necessary Fine grain and sievability results.

The material thus obtained is then in continuous tested batches chemically and analytically for their properties and pollutant levels examined. As an evaluation criterion in Germany can use the LAGA leaflet "Recycling Bö "are usually used conditions for conductivity as well as for individual organic Encountered pollutants. Following a decision matrix will be listed under the patent claims treatment combinations.

The material possesses properties that exceed it the limit values for conductivity or Katio NEN / ANIONS result, the material is the Le subjected to aching process. The material is mixed with water in the continuous process oversaturated, leaving excess water oozes out of the material. Leaching continues until the conductivity measurement of the eluted water falls below the necessary values. The valid conductive value can be advantageous by calibrating with eluate measurements can be found in the laboratory. The material can after The water content falls below the value of the field capacity be used for recultivation purposes. The salty Leachate is concentrated and the salts are disposed of or recycled. If suitable, this can be, for example, an open Tausalz happen.  

Should be batch or continuous quality analysis reveal that organic or inorganic pollutants If the eluate value is exceeded, suitable additives are added given. The material is continuously fed through box mixers or vibrating tables, using a metering pump or other suitable nete type added and in a mixing drum or a dop compulsory pelwell mixer or other suitable type mixes.

The mixed good is then based on an incubation rent layered and implemented at regular intervals. It can other forms of incubation can also be selected. Especially Based on our test results, the Container incubation. This variant appears for smaller ones Plants or for settlements due to the better control of odor emissions the method to be the choice.

The type and amount of the additives are as follows specified:

• (1) Organic waste compost of maturity 2-6 or sewage sludge in Proportions of 0.01-30% by volume.
• (2) Grain cleaning dust, husks, chopped or ge ground straw or other land residues or products economic or forestry production in un treated, chopped or ground in portions from 0.01-30% by volume.  
• (3) Residues from food production in solid, liquid ger or pasty form in the proportions 0.01-15 vol%.
• (4) residues of sugar production, both with mainly organic components as well as mainly anorga African components, for example calcareous, in proportions from 0.01-15% by volume.
• (5) residues or products from the textile industry, chemi industry, especially fertilizer producers Divisions, provided they comply with the applicable limit values in An divide from 0.0001-20 vol .-%.
• (6) Residual materials and products from the clay, stone and earth industries strie, in particular loam, loess loam, marl, tuff stones, Stone flour, brick dust, in particular sieve material and other materials from building material recycling and recycling cling of landfill dismantling material in proportions of 0.001-30 Vol.%.
• (7) Excavation from construction work in proportions of 0.1-30% by volume.

Based on our tests, ideal quantities for or ganic aggregates of approx. 5-10 vol .-% found. The inorganic components act between 2-5 vol .-% opti times. The exact composition of the additives is determined according to the content of pollutants.

The aggregates break down the pollutants in the following ways:
Humification: According to the latest research results, organic pollutants can be integrated into the organic substance of the aggregate by chemical bonding. This process is called humification. Humification is a biochemical process that is maintained and accelerated by microorganisms. The necessary microorganisms are already in the starting substrate. The admixture of the aggregate gives them the necessary organic matrix and nutrients and auxiliaries. In the course of the humu sturnover on the incubation rent, the pollutants are enoxidized and thus eliminated. In addition, there is direct degradation by microorganisms.

Heavy metals and other organic contaminants due to the clay and limestone components of the aggregate fe bound and immobilized. Because of the fine-grained out In addition to the pure precipitation and sorption reaction also "aging" due to inclusion in microcrystalline Structures possible. This ensures safe and eco Logically compatible definition of the relevant components. The eluate values drop below relevant in the course of the incubation Limits. The material can thus be used for recultivation purposes be used.

Are both the limit values for the salinity and for individual organic pollutants are exceeded, the Be Leaching, admixture of additives and Incubation on the rent or in the container method neter combined.  

Use of the mechanism of humification for decontamination nation of organically contaminated material is very innovative. In important research projects by applicant Dr. Arboretum At the moment the mechanisms are being examined in detail, which are the basis of the mentioned renovation success.

The application of these mechanisms to the treatment of here mentioned substrates is new and therefore appears to us particularly interesting because the material to be treated already bring the appropriate microorganisms. A cost intensive ve cultivation of microorganisms and the application can omitted. It can be the "cold rotting" as well as the many years of remaining decommissioning material on the "Reactor landfill" can be seen as a pre-incubation. The the Humification-causing or inducing bacteria (e.g. Streptomycetes) and fungi were already sufficient there "bred" to the crowd.

The task of the method described here is the Re action components for humification in a suitable amount, in fine distribution and in high dispersion as homo as possible to mix with the material. For a homogeneous admixture special attention must be paid to this. Can continue Auxiliaries are added, which act as solubilizers, Be wetting agent or as immobilization component for anor ganic substances work.  

Since substances with a relatively wide C / N ratio are added, this is often too high in the starting substance ammonium by assimilation to biomass removed reliably and ecologically compatible.

Through the subsequent incubation, the Qua materiality as a recultivation substrate sert. Nutrient imbalances are balanced and the pools any readily soluble substances that may be present become strong reduced.

The substrate acts as soil improvement in the recultivation because it carries humus and the water holding capacity poorer Soils improved. Furthermore, it acts as a slow-acting Fertilizer and in this context is especially in horticulture (Planting trees, etc.) and in the forest recult to use the crossing.

By adding the additional treatment level Sedi mentation / (wet) screening after the leaching stage can be done the slurried material in a sedimentation basin the coarse-grained mineral components are subtracted. Al Alternatively, fine-grain material can be sieved using a (wet) sieve be separated. The fine sandy silty humus-rich Ma After drainage, material is then added to the incubation rent treated further. The process is particularly interesting if a combination of the leaching level with the sedimentati ons - / (wet) screening stage is possible. Especially in the middle  up to low salt levels, this should usually always be possible be.

The mineral material obtained here can also due to its properties, especially the low glow loss value, in many ways in civil engineering and road construction be used. The fine-grained and humic fraction will used in recultivation or in horticulture.

We see the following with regard to economic exploitation particularly interesting effects:

• (1) Due to the recycling of the materials mentioned relief of expensive landfill space can be achieved.
• (2) The recycling of the materials mentioned fulfills important ones national laws and regulations. It will be a technical one feasible and economically interesting recycling leads.
• (3) The fact that the aggregates mainly from the rest substance range is also for these substances given a meaningful utilization.

Claims (9)

1. The method, characterized in that a recycling substrate is obtained from a sieve fraction of 0-max 20 mm of rotted residual waste or landfill material in which existing salts are discharged by leaching and any existing pollutants by the addition of organic and inorganic additives and subsequent incubation are humified, broken down and / or immobilized. 2. The method according to claim 1, characterized in that before Adding additives through mineral components Sedimentation / (wet) sieving can be separated and only the humus-containing fine grain fraction with those under claim 1 mentioned additives and is incubated. 3. The method according to claim 1, characterized in that the following substances are used alone or in combination with one another as additive:
Organic waste compost of maturity level 2-6 or sewage sludge in proportions of 0.01-30% by volume
Grain cleaning dust, husks, chopped or ground straw or other residues or products of agricultural or forestry production in untreated, chopped or ground form in proportions 30 of 0.01-30 vol .-%.
Residues from food production in solid, liquid or pasty form in the proportions 0.01-15% by volume.
Residues from sugar production, both with mainly organic components and with mainly inorganic components, for example calcareous, in proportions of 0.01-15% by volume.
Residues or products of the textile industry, the chemical industry, in particular fertilizer-producing sectors, insofar as they comply with the valid limit values in proportions of 0.0001-20 vol .-%.
Residual materials and products from the clay, stone and earth industry, in particular loams, loess loams, marl, tufa stones, stone flour, brick dust, in particular screen material and other material from building material recycling and recycling of landfill dismantling material in proportions of 0.001-30 vol. -%.
Excavation of earth from construction work in proportions of 0.1-30% by volume 4. The method according to claim 2, characterized in that the following substances are used alone or in combination with one another as additive:
Organic waste compost of maturity 2-6 or sewage sludge in parts of 0.01-30 vol .-%.
Grain cleaning dust, husks, chopped or ground straw or other residues or products of agricultural or forestry production in untreated, chopped or ground form in proportions of 0.01-30% by volume.
Residues from food production in solid, liquid or pasty form in the proportions 0.01-15% by volume.
Residues from sugar production, both with mainly organic components and with mainly inorganic components, for example calcareous, in proportions of 0.01-15% by volume.
Residues or products from the textile industry, the chemical industry, in particular fertilizer-producing sectors, insofar as they comply with the applicable limit values in proportions of 0.0001-20 vol .-%.
Residual materials and products from the clay, stone and earth industry, in particular loam, loess loam, marl, tuff stones, stone flour, brick dust, in particular sieve passage material and other material from building material recycling and recycling of landfill dismantling material in proportions of 0.001-30 vol. -%.
Excavation of earth from construction work in proportions of 0.1-30% by volume 5. The method according to claim 2, characterized in that the Leaching and sedimentation / (wet) sieving of the coarser grains gene fraction is carried out in one operation. 6. The method according to claim 1, characterized in that each according to pollutant levels and requirements for admixture of additives and the subsequent incubation is tested.   7. The method according to claim 2, characterized in that each according to pollutant levels and requirements for admixture of additives and the subsequent incubation is tested. 8. The method according to claim 5, characterized in that each according to pollutant levels and requirements for admixture of additives and the subsequent incubation is tested. 9. The method according to claim 1, characterized in that each for pollutant levels and requirements for leaching is waived.