A kind of light filter medium for water treatment and its preparation method and application

Abstract

The invention provides a light filtration medium for water treatment and a preparation method and application thereof, and belongs to the field of water treatment. The light filtration medium for water treatment adopts granular foam glass. The preparation method of the light filtration medium includes the following steps: adding a foaming agent, a foaming agent promoter and a modifier into the fine glass powder, and mixing uniformly to obtain a mixed raw material; smelting and foaming the mixed raw material, and then sequentially cooling and smashing again, so as to obtain the foam glass which can be used as the light filtration medium for water treatment. The foam glass has the characteristics of being high in voidage, large in specific surface area, porous and light; during the using process, the filtering speed is high, the effluent quality is excellent, and the material filtering layer is quite easy to expand (with a highest expansion ratio of 200%) during back washing, which facilitates the back washing in a fast and effective manner and provides guarantee for performing microflocculation rapid filtration; in addition, the surface of the foam glass filtration medium is uneven with multiple corner angles, high in voidage and large in specific surface area, and has excellent suspended solids retention property.

Description

technical field [0001] The invention relates to the field of water treatment, in particular to a lightweight filter medium for water treatment and its preparation method and application. Background technique [0002] Filtration is the most widely used process technology in the field of water treatment. At present, almost all water purification industries must use filtration technology. Moreover, with the strengthening of environmental protection laws, most urban sewage treatment plants must meet the first-class A standard in the "Pollutant Discharge Standards for Urban Wastewater Treatment Plants GB18918-2002". Therefore, filtration technology has also become one of the indispensable treatment methods for urban sewage treatment plants to reach the first-class A standard. [0003] In related technologies, considering factors such as the economy, maturity and practicability of treatment, in the existing filtration technology, the traditional sand filtration technology with or...

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Problems solved by technology

[0004] However, in the existing sand filtration technology, due to the high specificity of the sand filter material (above 2.60), it is difficult to achieve relatively sufficient backwashing, and the amount of backwashing water is large; secondly, due to the low porosity of the quartz sand filter material (50 % below), small surface area (0.04m 2 / g), so its pollution interception ability is poor, and there are also the status quo that the filter material is easy to harden (dead zone), frequent backwashing (because it is difficult to achieve sufficient backwashing, so the number of backwashing is often increased), which seriously affects the Water quality and production efficiency of water plant effluent

Therefore, due to improper selection of filter media, the existing sand filter technology has many problems such as high energy consumption, short filter cycle, and low efficiency.

[0005] In addition, in order to achieve the purpose of removing TP (total phosphorus) in the biochemical effluent, the current sewage treatment plant must add a flocculation process

However, when direct micro-flocculation filtration is performed after flocculation, due to the increase of suspended matter content in the filtered water, it is more likely to cause blockage and hardening (dead zone) of the filter layer, which leads to more prominent problem of hardening of the filter material

Therefore, only the "flocculation-sedimentation-filtration" process can be used, which adds an additional sedimentation process. In this way, not only the construction funds are greatly increased, but the sewage treatment process is too long, the facility occupies a large area, and production management is difficult. Difficulty and increased operating costs, etc.

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