Upward flow biological aerated filter and aeration method thereof

Abstract

The invention belongs to the technical field of sewage treatment, and discloses an upward flow biological aerated filter. The filter comprises a water distribution area, a supporting layer, a biological filler layer and a clear water area which are arranged from bottom to top in turn, wherein a water inlet distribution pipe and a first aeration distribution pipe are arranged in the water distribution area; the clear water area is connected with a water outlet pipe; and a second aeration distribution pipe is arranged in the biological filler layer. The invention also discloses an aeration method of the upward flow biological aerated filter. Dissolved oxygen concentration and mass transfer efficiency in a junction area of heterotrophic bacteria and nitrifying bacteria in the filter are improved in a two-time aeration mode, the distribution of dissolved oxygen along the height of the biological filler layer is optimized, aeration energy consumption is reduced, the mass propagation of thenitrifying bacteria is effectively promoted, and nitrifying efficiency is improved, so that the removal rate of NH4<+>-N is improved, the consumption of a carbon source is inhibited, and a necessary carbon source is kept for a subsequent denitrifying unit.

Description

technical field [0001] The invention relates to a sewage treatment system and an aeration method thereof, in particular to an upflow aeration biological filter tank and an aeration method thereof. Background technique [0002] Biological aerated filter, referred to as BAF, is a new sewage treatment process developed on the basis of ordinary biological filters from the late 1980s to the early 1990s, drawing on the water supply filter process, and is a deformation process of ordinary biological filters , can also be regarded as a special form of biological contact oxidation method, that is, the bioreactor is filled with granular fillers with high specific surface area to provide the carrier for biofilm growth, and it is divided into upflow or downflow according to the direction of sewage flow After the sewage flows through the biofill layer from top to bottom, it is blown and aerated in the lower part of the biofill layer, and the air and the sewage are in contact with each ot...

AI Technical Summary

Problems solved by technology

At present, in order to save infrastructure and operating costs, sewage treatment plants generally use carbon oxidation / nitrification tanks (C / N tanks) to decarbonize and partially nitrify sewage, and this kind of decarbonization and nitrification is the same as the upward flow of aerated organisms in the tank. Although the filter can ensure the degradation of chemical oxygen demand (COD) at the bottom, and the COD removal rate is high, its nitrification efficiency is low, and ammonia nitrogen (NH 4 + -N) removal is not ideal

The existing method is to improve nitrification by increasing the gas-water ratio at the bottom. Although this method can increase the dissolved oxygen concentration in the nitrification zone, an excessively high gas-water ratio at the bottom will easily cause excessive erosion of the biofilm at the bottom and weaken the impact of the biofiller layer. Suspended solids (SS) interception capacity; at the same time, excessive aeration causes excessive consumption of carbon sources. For the subsequent denitrification biological denitrification, insufficient carbon sources affect the denitrification effect

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