A biological aerated filter and its process

Abstract

The invention relates to a biological aerated filter and a process. The biological aerated filter comprises a double-pool biological aerated filter body, an aerator pipe which is positioned at the bottom of the biological aerated filter and is connected with an air blower, an effluent weir, a water inlet, a water outlet, a water distributor and a backwash drainage pipe, wherein the double-pool biological aerated filter body is communicated with the effluent weir positioned on the upper part of the double-pool biological aerated filter body; the bottom of the effluent weir is communicated with the backwash drainage pipe; the water inlet and the water outlet are respectively formed in the pool bottom of a single pool of the double-pool biological aerated filter body; the water inlet and the water outlet are respectively communicated with the water distributor. By taking swastika-shaped flexible biological packing as packing of the biological aerated filter, the biological enrichment time in the starting period is shortened from 30 days of the traditional biological aerated filter to 6 days, the biological concentration can be 15g / l, and the total microbial biomass is increased, so that the time of biodegrading organic matters in the same amount is shortened by 1 / 3, and the volumetric loading can be 1.4kgBOD / m3.d.

Description

technical field [0001] The invention belongs to the field of industrial sewage treatment, and in particular relates to an aerated biological filter and a process. Background technique [0002] Biological Aerated Filter (BAF for short) is an aerobic or anoxic bioreactor that uses granular filter material to fix biofilm. The functions of SS, CODcr, BOD, nitrification and denitrification, nitrogen and phosphorus removal, and AOX removal are emerging new technologies for sewage treatment in the world. [0003] The biological aerated filter is a third-generation biofilm reactor, which not only has the advantages of biofilm technology, but also plays an effective role in spatial filtration. The principle of biological aerated filter for sewage treatment is the oxidative decomposition of microorganisms in the biofilm grown on the filler in the reactor, the adsorption and interception of the filler and the biofilm, the graded predation of the food chain formed along the direction o...

AI Technical Summary

Problems solved by technology

[0008] At present, the biological aerated filter process is divided into two types: upward flow and downward flow according to the different water flow directions. The early biological aerated filter mostly uses downward flow, but the downward flow biological aerated filter has many disadvantages. Such as low pollution-holding efficiency, easy to block, short operating cycle, etc.; the upward flow method can make the water and air distribution more uniform, and the SS intercepted at the bottom can be brought into the middle and upper part of the filter when the water vapor rises, increasing the filtration capacity. The dirt-holding capacity of the pool prolongs the working cycle, but the upward flow also has disadvantages, such as slow microbial enrichment, easy to fall off biofilm, poor impact resistance, and low operating flexibility

[0009] At present, the biological aerated filter process is mainly based on rigid fillers. The rigid fillers have the following disadvantages: the fillers are difficult to form film, the total surface area is small, the total biomass of the film is small, the biofilm is easy to fall off during the backwashing process, and the dirt holding capacity is limited; The traditional soft filler has a larger surface area, more film formation than hard fillers, and faster film formation. However, there are many problems with traditional soft biological fillers. For example, traditional soft fillers tend to harden after long-term use. , the long mass transfer distance makes the internal mass transfer difficult, and it is easy to cause the problem of lack of oxygen inside the filler.

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