HU211757B - Process for anaerobic-aerobic biological purification of sewage and refuse water comprising many organics - Google Patents

Abstract

The present invention provides a method for purifying high organic matter contamination and waste water by combining anaerobic aerobic biological purification techniques. In the process, the wastewater and waste water to be cleaned, depending on the organic matter content, is fed into an anaerobic stage consisting of cascade-coupled disperse, preferably mixer (s) (1, 2, 3) and heterogeneous fixed film reactor (s) (4). , and after the acidic and / or methane fermentation, the organic material from the pre-purified wastewater is removed from the pre-purified wastewater in an aerobic biological stage from the heterogeneous fixed film reactor (s) (6) and the settling (s) (7), which are connected in series. extent. Prior to the anaerobic (and) or aerobic fixed-film reactors (4 and 6), sedimentation reactors (3 and 5) are introduced to eliminate clogging. EN 211 757 B Scope of description: 4 pages (including 1 sheet)

Description

The present invention relates to a process for the treatment of high organic matter wastewater by combining anaerobic and aerobic biological purification technologies.

In advanced industrialized countries, the purification of liquid wastes and wastewater of industrial or agricultural origin containing high concentrations of pollutant organic matter in a combination of anaerobic and aerobic biological systems is rapidly spreading. Increased requirements for purification efficiency mean that lower organic matter content and even lower nitrogen and phosphorus content in wastewater treatment systems must be achieved. this is the case nowadays in our country as well, and the cleaning requirements in Hungary will only increase.

Anaerobic processes are capable of decomposing organic materials into concentrated wastewater and converting it into gaseous and inorganic compounds with up to 80-90 percent efficiency. Depending on the initial organic matter content, the organic matter content of the effluent discharged after such a process may well exceed the organic matter content of domestic, urban raw sewage, thus requiring further purification and decomposition of organic matter. This can only be achieved by aerobic procedures. It should also be borne in mind that after many industrial wastewater and anaerobic purification processes, it may still contain significant ammonia and sulphide contamination, which oxidation to nitrate or sulphate is essential as they would otherwise consume the oxygen of the receiving living water. and would be toxic to the biological community. The phosphorus content of wastewater is also biologically reduced by an aerobic system, although additional anaerobic processes play a role.

All in all, anaerobic processes are energy-efficient and even energy-producing (methane gas). thus, it is economical to extract concentrated organic contamination from water but with insufficient efficiency in terms of direct discharge into living water. That is why a second purification step must be provided, which can only be an aerobic process.

Among the anaerobic biological wastewater treatment processes are the so-called contact and fixed film processes.

In the "contact" anaerobic process, the waste water treatment (biodegradation of the organic material) is carried out in a separate fermenter (anaerobic sludge reactor) and a post-settler, or in a plant consisting of a super-stacked fermenter and post-settler. The disadvantage of the "contact" procedure is, on the one hand, low load capacity and, on the other hand, demanding commissioning time.

In ftx-film anaerobic processes, the fermentor is loaded with a charge on which the microbiological population settles. The disadvantage is that the cartridge containing the fixed film is easily clogged.

Air-sprayed water-dripping drip bodies are also known as an aerobic biological wastewater treatment process. This method is in principle a fixed film aerobic method and has the advantage over the also well-known activated sludge process that the biological population of wastewater treatment adheres to water-immersed support pads without the need for frequent, and especially, heavy phase separation in industrial wastewater treatment , just the air-blown excess biological membrane deposition, as well as the conventional drip-body system, not water-coated, but truncated. The latter, however, has the advantage of a much higher organic matter load and its controllability by artificial oxygen supply.

SUMMARY OF THE INVENTION It is an object of the present invention to overcome the drawbacks of the known processes by providing a combined process which has a high efficiency of wastewater treatment and / or high efficiency. it can meet the purified water criterion while reducing the total cost of wastewater treatment, including in particular energy costs.

The present invention is based on the discovery that the above object is achieved by combining an anaerobic biological system consisting of multi-stage dispersed biomass homogeneous reactors and fixed-film biomass heterogeneous reactors with one or more additional aerobic biological steps comprising heterogeneous but aerated reactors and settlers.

The present invention therefore relates to a process for the treatment of high organic matter wastewater by combining anaerobic and aerobic biological purification technologies. In the process, the wastewater to be treated is fed into an anaerobic stage consisting of a cascade of dispersed reactor (s), preferably heterogeneous fixed film reactor (s), in a sequence depending on its organic matter content. After acidic and / or methane fermentation, the organic material is sequentially removed from the pre-treated wastewater to the desired extent in an aerobic biological step consisting of a series of heterogeneous air-blown fixed-film reactor (s) and after-settling.

A beneficial effect is achieved by installing sedimentation reactors in front of the anaerobic and / or aerobic fixed film reactors.

A further advantageous effect is obtained by returning the excess sludge from the aerobic and anaerobic stage settlers to the first dispersed reactor of the anaerobic stage.

It is also advantageous to introduce the effluent into the aerobic stage fixed-film reactors distributed over their entire surface and similarly to discharge the purified water.

The pre-treated wastewater is passed from the last anaerobic stage settler through a water seal and degasser to the aerobic stage fixed film reactor.

The process according to the invention is illustrated in more detail by way of example in the drawing. 1 is a flowchart of a possible embodiment of the method.

The raw sewage is fed to a 1-stirred reactor. After acid fermentation and equilibration, the effluent is subjected to methane fermentation in a 2 stirred reactor. After pre-settling in 3 pre-setters, further methane fermentation was performed on 4 fixed-film reactors. After methane fermentation, additional sedimentation was performed in 5 settlers. From the settler 5, the aerobically pre-treated wastewater is fed through a water seal 8 and a degasser to a fixed-film reactor 6, where anaerobic biological purification is carried out, with 9 compressors providing the air needed for oxidation. Sludge deposited in post-settler 7 in pre-settler 3,

It is fed back to the mixing reactor 1 by means of a pump 10, together with the sludge settled in the settler 5. The purified water is led from the post-settler Ί to the recipient. From the pre-settler 3 and settler 5, the anaerobic stabilized excess sludge is removed via the sump guide pipes 11 and 12, respectively.

The main advantages of the process according to the invention are as follows:

- the combination of anaerobic and aerobic systems takes place in a reactor cascade of exactly the same design,

- the anaerobic and aerobic systems can be designed by cascading the cascade elements in any number and purpose, so that the aerobic staircase shown in Figure 1 can be supplemented with an additional aerobic staircase, which allows for the effective purification of wastewater containing all kinds of organic matter,

- intermediate settlers allow plug-in reactors to operate without plugging,

- after the aerobic fixed film reactor, only the excess sludge with good sedimentation capacity settles and can be traced back to the beginning of the anaerobic system for further anaerobic fermentation, thus leaving the system only anaerobically stabilized sludge, which is known to be very small compared to the aerobic stabilized.

Claims (5)

PATENT CLAIMS A process for treating wastewater with high organic matter content by combining anaerobic and aerobic biological purification technologies, characterized in that the wastewater to be purified is cascaded in a sequentially connected dispersion reactor (s) (1) and (2) according to its organic content. the heterogeneous fixed-film reactor (s) (4) to anaerobic stage, followed by acid and / or methane fermentation, alternately connected in series with the heterogeneous air-blown fixed-film reactor (s) (6) and post-settler (s) (7) ) in a stationary aerobic biological stage, the organic matter is removed from the pre-treated wastewater to the desired extent. Process according to Claim 1, characterized in that settling reactors (3 and 5) are installed in front of the anaerobic and / or aerobic fixed-film reactors (4 and 6) in order to eliminate blockage. Process according to claim 1 or 2, characterized in that the excess biological sludge deposited in the aerobic stage post-settler (7), together with the sludge removed from the anaerobic stage settler (3 and 5), is recycled to the first agitator reactor (1). 4. A process according to any one of claims 1 to 4, characterized in that the aerobic stage is fed to the fixed-film reactor (s) (6) evenly distributed over their entire surface and similarly discharged purified water. 5. A process according to any one of claims 1 to 3, characterized in that the pre-treated waste water from the last settler (5) of the anaerobic stage is fed through a water seal and a degasser (8) to the fixed film reactor (6) of the aerobic stage.