DD255523A1 - METHOD FOR MICROBIAL REMOVAL OF WATER INGREDIENTS - Google Patents

Abstract

The method is used for the microbial degradation of water constituents. The aim of the invention is a method with which by creating optimal living conditions for sessile microorganisms high degradation capacity in the smallest space with low energy consumption is possible. The invention has for its object to achieve the microbial degradation by special Begünstigung the growth of sessile microorganisms on Befuchstraegern. The object is achieved by a method, according to which for this purpose the vegetation carriers are constantly or temporarily brought within a reactor with simultaneous oxygen supply to circulation.

Description

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Field of application of the invention

The invention relates to a method for the microbial degradation of water constituents by special promotion of the growth of sessile microorganisms on constantly or temporarily placed within a reactor with simultaneous oxygenation for circulation Soil carriers.

Characteristic of the known state of the art

A method is known in which the water to be treated passes through the filter layer of a fixed bed reactor and is freed by growing on the filter material organisms of biodegradable substances, a partial flow of the

Filtrats vented and again the Filteroberflächezuzugeführt. ,

In another method, to be referred to as a countercurrent reactor with respect to water and air, granular growth support material having a density just below that of water (1 g / cm ² >ς> 0.9 g / cm ³ ) is suspended by effluent water , wherein a floating is prevented by controlling the outflow velocity or grates or screens. In the case of the aerobic mode of operation is aeration by compressed air in countercurrent.

Other methods use fixed or mobile growth carriers of various shapes and materials to increase the degradation efficiency in possibly specially shaped basins. Furthermore, fluidized or floating bed processes are known in which the vegetation carrier material, often gravel or sand, is held in the fluidized bed or in the suspended bed by a high velocity of the upflowing water.

The disadvantages of the said methods consist in a low utilization of the oxygen introduced by the air due to short water-air contact distances, in the need to produce a large flow rate with a correspondingly high energy consumption in order to achieve the required oxygen input and sufficient turbulence or compressed air to provide for the oxygen supply.

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Fixed bed reactors require a filter bottom for the filtrate, the return or free flushing with both constructive and operationally conditioned additional effort. If no backwash capability is provided, a minimum grain size of the fouling carrier material is required to ensure the automatic leaching of bacterial mud, thereby limiting the growth area for the microorganisms. The floor constructions themselves are clogged.

The process according to the countercurrent principle has the disadvantages that to ensure the floating state of the Befuchtträgermaterials constantly ensures a constant speed of the downward flow and the air must be accurately metered by means of separate units in uniform distribution over the cross section.

Additional grates or screens cause hydraulic losses which increase due to growth or clogging.

The use of fixed vegetation carriers in activated sludge treatment plants using various types of ventilation systems requires complex fastening devices and a high intrinsic stability of the vegetation carrier material.

The fluidized or floating bed methods have the disadvantage that the energy to be applied to secure the required upward speed is high and abrasion of the growth as well as of the bedding material itself is unavoidable.

Object of the invention

The aim of the invention is a method that creates optimal living conditions for sessile microorganisms and their metabolic processes while avoiding the disadvantages mentioned, in order to ensure a high degradation performance in the smallest space and with minimal energy consumption.

Explanation of the essence of the invention

The invention has for its object to provide a method for microwave degradation of water constituents by special favoring the growth of sessile microorganisms on vegetation carriers, in which the vegetation carriers by matched flow rates within mutually delimited spaces of a reactor temporarily or continuously, partially or in their entirety The volume flows are made to circulation and the oxygen supply to the microorganisms is ensured by aeration of a volumetric fraction, which also generates the required flow rates in the reactor.

According to the invention, the object is achieved by a method in which a constant or within certain limits variable volumetric flow outside of the reactor by negative pressure generation in a nozzle or drop section with atmospheric air and introduced together with the partial volume flow at a predetermined depth in a delimited preferably cylindrical inner reactor area , The upward flow initiated thereby effects a total discharge of the water to be treated on the water surface of the reactor and beyond the cylindrical reactor region a predetermined downward flow which passes or penetrates the preferably buoyant growth carriers and the sessile microorganisms from the air introduction point up to here supplies dissolved oxygen in the water. The marginal space between the cylindrical inner reactor region and the reactor walls is filled with growth carriers at such a height that, depending on the flow velocity, either the total mass of the vegetation carriers or a selectable subset is detected by the flow in the cylindrical reactor region and conveyed to the water surface. In this way, the vegetation carriers are exposed to a continuous change of location in the reactor, the entire reactor space is used as a treatment zone and caking due to the growth of microorganisms excluded.

Excess sludge is discharged from the reactor continuously with the effluent of the purified water.

If a volume-related surface and the density of the vegetation carrier material are kept, its size is freely selectable in the sizes 0.05 <di 50 mm. The reactor size is between small equipment e.g. for the purification of aquarium water up to treatment plants for the industry or big cities realizable.

With the hydraulic system, a 20 to 180-fold circulation per hour is generated in the reactor, wherein the hydraulic load relative to the surface of the peripheral space of the reactor between preferably 50 and 200m ³ · h " ¹ · m" ² selected

The recirculation capacity and sufficient oxygen supply is achieved with an air-water factor β > 0.25 of the ventilated volume flow.

embodiment

The method according to the invention is explained by the following embodiment shown in FIG. 1:

From the into a reactor! introduced water to be subjected to a microbial treatment, a Voiumenteilstrom 3 is removed by means of a pump 2, mixed in a nozzle 4 with atmospheric air 5 and passed from below into a cylindrical reactor region 6 open there and above. The cylindrical reactor region 6 starts at a predetermined height above the reactor bottom 7 and ends below the water surface 8 in the reactor 1.

The demarcated by the cylindrical inner reactor region 6 edge space 9 of the reactor 1 is filled with buoyant Bewuchsträgern 10 whose mass protrudes above only slightly above the water surface 8 and ends near the lower edge of the cylinder. With the water-air mixture 11 introduced into the cylindrical reactor region 6, a quantity of water 3 which exceeds the volume flow 3 which is generated several times by the pump 2 is conveyed to the water surface 8 and at the same time enriched with oxygen from the introduced air 5. The oxygen-enriched water is after

Separating the air bubbles at the water surface 8 fed back in the direction of the reactor bottom 7, thereby flows through the vegetation carrier 10, softened (possibly by seeding) sessile microorganisms are brought to the growth, and supplies them with oxygen. The resulting oxygen depletion is compensated by reintroduction of the water into the cylindrical reactor region 6 and oxygen enrichment taking place there. The rate of rise of the water in the cylindrical reactor region 6 and the descent rate in the edge space 9 are coordinated so that. On the one hand, a high circulation of water in the reactor 1 takes place, on the other hand, however, the buoyancy rate of the vegetation carrier 10 is greater than the descent rate of the water. Furthermore, the rate of ascent in the cylindrical inner reactor region 6 is so great that the vegetation carriers 10 located near the lower edge of the cylinder are entrained by it to the water surface 8, where they overlay the vegetation carriers 10 located above and slowly continue the entire mass of the vegetation carriers 10 in the edge space 9 push down, which again entrained the lowest vegetation carrier TO from the flow in the cylindrical reactor region 6.

The inflow 12 to the reactor 1 is controlled so that the set for the required mikrobieljen degradation of the water constituents within a predetermined reaction time conditions are met, while the outflow 13 is carried out as an overflow automatically ,

Claims (7)

A process for the continuous microbial purification of water using granular or specially shaped vegetation carriers which have a large specific surface area as growth area for sessile microorganisms and fill a reactor space completely or partially. Characterized in that the water and the Bewuchsträger be brought together with the help of a ventilated volume flow of water constantly or if necessary together to circulation and the ventilation of the water partial flow of the required for the metabolic processes of microorganisms oxygen is added, the entire reactor space is used as a treatment zone and to contribute to the density of the vegetation carriers in the range of 1.1-0.9 g / cm ³ , preferably 1.05-0.95 g / cm ³ . 2. The method according to claim 1, characterized in that the aerated volumetric flow of the water is introduced near the bottom of the reactor in a cylindrical reactor space in which by means of the water-air mixture of the volumetric part flow a volumeileilstrom is generated by the multiple surpassing total flow, the Flow rate is often greater than the rate of descent of the vegetation carrier material of a density> 1 g / cm ³ and by which the vegetation carriers are included in the circulation. 3. The method according to claim 1 and 2, characterized in that the circulation of the growth carrier a density <1 g / cm ³ caused by changing the circulation rate of the water as needed and in the meantime, the oxygen-rich water is passed through the acting as a filter layer mass of the vegetation carrier , 4. The method according to claim 1 and 2, characterized in that the growth carrier of the density <1 g / cm ^{3 is} constantly taken in a predetermined amount of the lower lamella of the mass of the vegetation carrier and piled with the upward flow in the riser to the upper vegetation carrier to a to achieve gradual rearrangement within the reactor. 5. The method according to claim 1 and 2, characterized in that the required for the oxygen supply of microorganisms and for the generation of circulation in the reactor air is mixed without additional air compressor plant in the partial water flow, wherein the air-water factor β preferably between 0, 2 and 0.6 should be. 6. The method according to claim 1 and 2, characterized in that a mixture of different types of vegetation carriers is used as the vegetation carrier material. 7. The method according to claim 1 and 2, characterized in that the relative speed of the water relative to the Befuchtsträgermaterial can be between 0 and 300m / h, preferably between 0 and 200 m / h.