Method for controlling turbidity of initial filter water in quick filter tank after backwashing and micro-expansion washing

Abstract

The invention discloses a method for controlling turbidity of initial filter water in a quick filter tank after backwashing and micro-expansion washing, and belongs to the technical field of filtration in drinking water treatment. The method is characterized in that: after the backwashing of the filter tank, wash water is not immediately cut off completely, and micro-expansion washing for 1 to 7 minutes is carried out; the filter layer expansibility of the micro-expansion washing is 3 to 5 percent, the washing duration depends on the inflow turbidity and filtration rate when the filter tank is operated; when the inflow turbidity of the filter tank is 1 to 3 number of transfer units (NTU) and the filtration rate is 6 to 10m / h, the micro-expansion washing is kept for 1 to 3 minutes; and when the inflow turbidity of the filter tank is more than 3NTU and the filtration rate is more than 10m / h, the micro-expansion washing is kept for more than 3 minutes and less than 7 minutes. The principle is that: the pore structure of the washed filter material layer is improved through the micro-expansion washing, and residual particles are further removed, so that the turbidity of the initial filter water is reduced.

Description

technical field [0001] The invention relates to a method for controlling the turbidity of primary filtration water in a fast filter tank by adding micro-expansion flushing after backwashing, and belongs to the technical field of filtration in drinking water treatment. Background technique [0002] At present, in drinking water treatment, there is a problem that the turbidity of the initial filtration water after backwashing of the fast filter is slightly higher than the turbidity of the effluent during normal filtration. my country's "Outdoor Water Supply and Drainage Design Code" (GB50013-2006) clearly states that "except for filters that cannot be equipped with primary filtration water discharge facilities during filter construction and operation, filters should be equipped with primary filtration water discharge facilities." The U.S. Environmental Protection Agency’s requirement for the turbidity of the primary filter water is that the maximum turbidity of the effluent fr...

AI Technical Summary

Problems solved by technology

The two methods can improve the turbidity of the primary filtration water to a certain extent, but will have a greater impact on the water production rate of the filter

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