DE202011110704U1 - Substances for the treatment of sewage sludge - Google Patents

Abstract

A sludge treatment product comprising: - effective microorganisms; - Water; and - at least one disinfecting and / or odor-neutralizing chemical.

Description

Technical area

The invention relates to materials for the treatment of sewage sludge, in particular substances that allow use of the sewage sludge as fertilizer or building material.

State of the art

Sewage disposal involves the production of large quantities of sewage sludge, which to a significant extent consists of solids. To reduce the volume of sewage sludge is treated anaerobically in digestion towers, whereby the amount of solids can be reduced. Due to the high phosphate and nutrient content, the resulting stabilized sewage sludge is basically available as a fertilizer, although a heavy metal exposure to this use may also occur. Only a small part of the sewage sludge is used for the fertilization. The larger part has to be burned. However, the stabilized sewage sludge due to the still high water content has a poor calorific value, which is why the combustion energetically brings little or no profit and therefore no recovery, but a cost-causing disposal.

Disposal at a landfill is prohibited by law. A change in the legal regulations regarding the use as fertilizer can further restrict this utilization purpose, which is already the case in some European countries.

Sewage sludge can also be used as an admixture to building material, but only a mixing ratio sewage sludge building material of 1 to 10 or worse can be realized, otherwise the stability of the building material is too low. This use is thus also limited use.

The possibilities for recycling the sewage sludge are thus limited and a high proportion of the sewage sludge must be disposed of costly thermally. Therefore, there is a need to improve existing exploitation opportunities or to develop new ones.

Object of the invention

The object of the invention is to provide substances to improve the utilization of sewage sludge as a fertilizer and to allow as a building material.

Technical solution

This object is achieved by a first substance according to claim 1 or a second substance according to claim 4. Advantageous embodiments are the subject of the subclaims.

The first substance includes effective microorganisms (EM), water and disinfecting and / or odor neutralizing chemicals. The latter are preferably saponins and glycols, in particular triethylene glycol. Furthermore, sugarcane molasses or other nutrient for bacteria may also be added to properly control the life of the effective microorganisms. Likewise, through a period of storage with the help of sugar cane molasses or other nutrients, an increase in the number of organisms (EM breeding) can be awaited and the saponin or other chemicals can be added wholly or partially afterwards.

Examples of possible saponins are aglycones, in particular steroid saponins, steroid alkaloid saponins and / or triterpene saponins. The saponins may also be of natural origin, such as from soapnut. Technically possible but not preferred alternatives to triethylene glycol are cyclodextrins.

Effective microorganisms are usually a mixture of various naturally occurring microorganisms. The most common is a large proportion of lactic acid bacteria, yeasts, especially baker's or brewer's yeast, and / or photosynthetic bacteria or non-sulfur adult bacteria, although other combinations of bacteria or the admixture of smaller amounts of such can be used. Almost any amount of effective microorganism can be grown by adding a small amount of organisms to it by adding sugar cane molasses or other nutrient. For the breeding of the effective microorganisms, it may be advantageous to use first a carrier liquid with high sugar cane molasses / nutrient content and to carry out a dilution with water after a sufficient breeding time. Depending on the composition, a ratio of 1 to 10 may make sense. When used in the context of this invention, the EM serve, inter alia, the reinforcement of fermentation processes.

Preferably, the mixing ratio of EM to water to triethylene glycol to sugar molasses to saponin for the first material in the range 1 to 6 to 10 to 0.005 to 0.03 to 0.3 to 2 to 0.3 to 3, the entire saponin only after completion the EM-breeding is added. Technically, a strong reduction of the EM content is possible with a relatively further increase in the saponin content, but not preferred. Further dilution with water in a ratio of up to 1 to 10 is also possible.

By adding the first substance to sewage sludge harmful and / or strong-smelling bacteria are inexpensively eliminated, whereby the thus treated sewage sludge is used as fertilizer. It is sufficient to add 10 units of sewage sludge 1 to 4 units of the first substance to allow use as fertilizer. The application also changes the pH to more favorable for agriculture.

The second substance has a similar composition as the first substance, but still includes water glass, especially soda water glass. An example of other technically possible but uneconomical water glasses are potash water glasses. This results in a strong bond, and the treated sewage sludge solidifies (gradually more or less depending on the proportion of water glass). The treated sewage sludge can thus be used as a building material or be used in large admixture with another building material. This heavy metals are firmly enclosed by the added substance and can not be released by moisture. The second fabric preferably consists of 20% to 60% of the first fabric and 40% to 80% of water glass. Furthermore, a mineral powder of volcanic origin, in particular bentonite, can be added in an amount of up to 20%. Also, additional materials may be added to accelerate cure, with additive levels of up to 15% being preferred, the accelerating accelerators may include aluminum sulfates and / or resin-based thickeners. This mixture enables effective hydration of the sewage sludge.

The method consists in treating the preferably semi-dry or stabilized sewage sludge with the first material in the case of use as fertilizer and with the second material in case of use as building material, in both cases a pretreatment can be carried out. Semi-dry or stabilized sewage sludge is sometimes also referred to as fresh or moist sewage sludge, preferably the sewage sludge has a moisture content of 25% to 30%. The pretreatment comprises the treatment of the sewage sludge with an effective microorganism-containing solution, which may have a similar composition as the first material. The treatment itself comprises prolonged standing of the sewage sludge mixture, preferably 1 to 2 weeks. This may be followed by drying, pressing and / or comminution.

In the case of use as a fertilizer, the mixing ratio of first material to sewage sludge is preferably 1 to 4 to 10. In the case of use as a building material, the mixing ratio of second material to sewage sludge is preferably 2 to 7 to 10. The resulting material can be mixed in an admixture of 1 to 6 to 1 to 2 can be used as admixture in building materials, or the building materials can be added to the sewage sludge before the treatment depending on the exact material. Thus, when used as a building material, a considerably higher proportion of sewage sludge possible than in the admixture of the prior art, in which only an admixture of 1 to 10 can be realized.

As a final step, re-drying and / or comminution / trimming can take place, depending on the intended use.

Description of preferred embodiments

In preferred embodiments, the first substance comprises effective microorganisms, sugar cane molasses, saponins and triethylene glycol, the second material also sodium silicate and possibly bentonite.

An exemplary production process for 50 liters of the first substance comprises the mixture of 5 liters of EM, 38 liters of lukewarm water, 50 ml of triethylene glycol and 2 to 3 liters of sugarcane molasses. The liquid is then stored at room temperature for 2 to 3 weeks. After this time no further multiplication of the microorganisms takes place. Then 5 liters of saponin are added.

Further dilution with water in the ratio up to 1 to 10 can take place.

This first substance can be mixed with sewage sludge, preferably fresh or moist sewage sludge having a moisture content (liquid content) of 25% to 30%, preferably in a ratio of 1 to 4 to 10. After a further 1 to 2 weeks standing, waiting and / or dry season, the treatment is complete. The treated sewage sludge is odorless and contains no harmful bacteria and can be used due to the high nutrient concentration in principle as a fertilizer.

As an alternative to the first substance, the second substance can be reduced by a mixture of 20 to 60% of this first substance and 40% to 80% of sodium silicate, preferably also the sodium silicate content is reduced by up to a quarter and the equivalent amount of bentonite is added. Not preferred, but technically possible is the use of sands, quartz sands, tuff, volcanic sands, perlites or other materials which have a high reactivity with soda. Further, a hardener of up to 20%, preferably 15%, of the mixture may be added to the resulting mixture, the hardener preferably comprising aluminum sulfate and / or thickener based on a resin. Subsequently, this second material is mixed in the ratio of 2 to 7 to 10 with sewage sludge. After a suitable drying time, during which the weight is reduced by evaporation of the water by about 2/3, the treated sewage sludge is odorless, fire and water resistant and can be used well as a building material or as an admixture with other building materials. For example, depending on the application, mixing with sands, tufa, perlites, bentonites, sodium bentonites or calcium bentonites can yield a suitable building material. It can also be mixed with ash, straw, wood waste, hay or spews. The mixing can also be done depending on the material with the sewage sludge before the actual treatment. Above all, it is important that any heavy metals are safely and waterproofly incorporated into the material through the process.

For example, to 1000 grams of wet sewage sludge, 680 ml of the second fabric can be mixed, resulting in a total weight of 1680 grams. After drying remain 696 grams of material, which are odorless, hard, fireproof and waterproof.

Although the present invention has been described in detail with reference to the accompanying embodiments, it will be understood by those skilled in the art that the invention is not limited to these embodiments, but rather modifications or changes according to the appended claims, the changes by different combinations of individual illustrated features can also be done by omitting individual features. In particular, any combination of the illustrated features is encompassed by the invention.

Claims (8)

Sludge treatment substance comprising: - effective microorganisms; - Water; and - at least one disinfecting and / or odor-neutralizing chemical. A fabric according to claim 1, wherein the disinfecting and / or odor-neutralizing chemicals comprise saponins and / or glycols. A fabric according to claim 2, wherein the fabric further comprises nutrients for bacteria, especially sugar cane molasses. A fabric according to claim 3, wherein the fabric contains one unit of effective microorganisms, 6 to 10 units of water, 0.005 to 0.03 units of triethyl glycol, 0.3 to 2 units of sugar cane molasses, and 0.3 to 3 units of saponin. Sludge treatment substance comprising: A first substance according to one of the preceding claims, and - Water glass, in particular soda water glass. The fabric of claim 5, wherein the first fabric is from 20% to 60% of the second fabric and the content of water glass is from 40% to 80% of the second fabric. A fabric according to claims 5 or 6, further comprising mineral powder of volcanic origin, in particular bentonite. The fabric of claim 7, wherein the amount of bentonite is up to 20% of the fabric.