A backwashing device and method for a light-weight filter material biological aerated filter

Abstract

The invention relates to the field of sewage processing, and relates to a backwashing apparatus and a backwashing method for an aeration biofilter with a lightweight filter material. The backwashing apparatus for the aeration biofilter with the lightweight filter material comprises a tank, a lightweight filter material layer, a technical water inlet valve, a technical water outlet valve, and a backwashing water discharging valve. An aeration pipeline and a local backwashing pipeline are connected to the bottom of the tank. The aeration pipeline comprises an aeration device. The local backwashing pipeline comprises a local backwashing pump and a local backwashing perforated pipe connected to the local backwashing pump. A local backwashing starting valve is arranged on the local backwashingperforated pipe. The local backwashing perforated pipe is positioned in the lightweight filter material layer. The invention also provides a backwashing method for the aeration biofilter with the lightweight filter material. The apparatus and the method provided by the invention are advantaged in that: lightweight filter material mixing caused by the backwashing process is reduced, water consumption in the backwashing process is reduced, and agglomerated lightweight filter material can be flushed.

Description

technical field [0001] The invention relates to sewage treatment, in particular to a backwashing device and method for a light filter material aerated biological filter in sewage treatment. Background technique [0002] Biological Aerated Filter (BAF for short) is a new sewage treatment process developed in the late 1980s on the basis of ordinary biological filters and drawing on the water supply filter process. The biggest feature of the biological aerated filter is that it integrates biological oxidation and interception of suspended solids, saves the subsequent secondary sedimentation tank, and simplifies the treatment process on the premise of ensuring the treatment effect. Lightweight filter material aerated biological filter is a new type of BAF technology developed in recent years. Compared with the heavy filter material BAF process, it has the following advantages: ①Using light organic filter material, it is not easy to wear and lose, and the supplementary cost is lo...

AI Technical Summary

Problems solved by technology

The following problems exist in the conventional backwashing method: ① During the backwashing process, it is easy to cause mixed layers of filter material, the upper part of the filter material layer mainly adheres to nitrifying bacteria, and the filter material layer mainly adheres to heterotrophic bacteria. The filter material layer moves up, so that the sewage treatment effect of the filter at the initial stage of operation after backwashing is not good, especially for the removal of ammonia nitrogen; The amount of backwash effluent is large and the cost is high; ③The filter layer is easy to agglomerate during operation, and the conventional backwash method cannot effectively wash away these agglomerated filter materials, resulting in a decline in the subsequent treatment effect of the filter

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