Downflow double-layer filter material aerating biological filter and method for using the filter chamber to process raw water

Abstract

The invention discloses a down-flow biological aerated filter with double-layer filter media and a method to apply the filter for the processing of raw water. The filter is characterized in that a large-particle filter layer, a small-particle filter layer and a gravel layer are arranged in order below a backwash effluent groove in the biological aerated filter; processing aeration devices are arranged in the gravel layer; the particle size of filter media at the large-particle filter layer is from eight to sixteen mm with a smaller filter media density than the small-particle filter layer; the particle size of filter media at the lower small-particle filter layer is from four to eight mm. For the method, raw water enters into the filter through a water distribution channel, flows downward through the lightweight large-particle filter layer and small-particle filter layer and the gravel layer, and flows out through a filter head arranged at a filter plate. The down-flow biological aerated filter with double-layer filter media has the advantages of small water head loss and long backwash cycle, is a economical and efficient method in the biological pretreatment technology for micro-biological polluted drinking water sources.

Description

technical field [0001] The invention relates to a biological aerated filter, in particular to a biological aerated filter for purifying slightly polluted drinking water sources, in particular to a downflow double-layer filter material aerated organism for biological pretreatment of slightly polluted drinking water sources A filter and a method for pretreating raw water using the filter. Background technique [0002] Biological aerated filter is a new type of sewage treatment technology developed in the late 1980s. This technology uses granular fillers with high specific surface area as the biofilm carrier. The microbial biomass per unit tank is large, the treatment load is large, and the effluent quality is low. Well, there is no need to set up a secondary sedimentation tank in the future, it occupies a small area, saves capital investment, and because of the modular structure, it has a high degree of automation, is easy to manage, and is also convenient for later reconstruc...

AI Technical Summary

Problems solved by technology

Since the raw water in the feed water pretreatment often contains a large amount of impurities or aquatic organisms, in the case of long-term operation, it is easy to cause poor water flow, low treatment efficiency, and system failure due to blockage of the filter head.

In order to prevent the clogging of the filter head, the raw water must be strictly pre-treated, which greatly increases the construction and operation costs

The downflow biological aerated filter does not have the above problems, but because the general biological aerated filter uses small particle ceramsite filter materials with a particle size of Φ3-5mm, a large amount of suspended matter and turbidity are intercepted by the upper filter material during operation The upper layer of the filter material will be covered by slime in a short time to form a hardened layer, and the head loss will increase rapidly, thus forcing the filter to be frequently backwashed, which increases the operating cost and affects the filter with a long metabolic cycle. The normal growth of nitrifying bacteria affects the removal rate of ammonia nitrogen

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