SU921594A1 - Auxiliary filtering material for precoat filtering - Google Patents

Description

(54) AUXILIARY FILTER MATERIAL FOR CLEANING FILTERING

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The invention relates to the treatment of wastewater and can be used, in particular, for the purification of biologically treated wastewater by filtration. Sand loading filters are known that are used for the purification of biologically 5 treated wastewater 1.

However, the construction of such filters. requires significant capital investments (40-60 / 0 of the cost of biological treatment facilities), as well as large pro-Q production areas, and their operation is associated with significant costs for the regeneration of the filter load, carried out by water or air washing.

Also known tertiary treatment of wastewater 15 on alluvial filters (drum, disc, sheet or frame) on the filter wall which wash layer of auxiliary material, through which then biologically treated, 0 waste water is filtered. In particular, perlite 2 is used as an auxiliary material.

However, when filtering through a layer of perlite even at low speeds (up to

4.M / H) there is a rapid increase in losses — pressure. Therefore, to increase the duration of the filter cycle in the filtering filtering process, in-. There is an additional amount of 3–9 g per 1 g of suspended solids contained in the filtered water, which is associated with a high consumption of this expensive special auxiliary material, and, accordingly, increases the cost of additional treatment.

In addition, wastewater treatment plants with such filters require tailing organization to remove and store spent perlite, or to introduce a regeneration unit into the flowchart that is dried by calcination, which is associated with high energy consumption.

The purpose of the invention is to reduce the cost of after-treatment, increasing the filtration speeds, as well as ensuring repeated use of the auxiliary material while simplifying its regeneration process.

This goal is achieved by using natural waste concentrate as an auxiliary filter material for the purification of biologically treated wastewater.

Aegirin concentrate is a waste product of rare metals, and its cost when used as an auxiliary filtering material is determined only by the amount of transportation costs.

At the same time, filtration with the use of waste aegirin concentrate can be carried out at speeds up to 15 m / h, which is several times higher than the filtration speeds when using special auxiliary filtering material (perlite).

In addition, after the completion of the filter cycle, the egirin concentrate can be easily regenerated by washing it with a small amount of water, which makes it reusable.

Example. Spent aegirin concentrate with a particle size of 60-300 microns is wound with a layer of 20-40 mm on the filter screen of the laboratory filter.

Biologically treated municipal wastewater with a concentration of suspended substances of 15–20 mg / l is filtered through the prepared precoat layer. Filtration speed 15 m / h.

With a filter cycle duration of 3-3.5 hours, the removal efficiency of suspended solids is 75-80%, i.e., it is not inferior to regulatory data for the purification of wastewater.

The contaminated aegirin concentrate is removed from the filter septum, displaced with filtered water at a liquid-solid (15-20): 1 ratio, which corresponds to a wash water consumption of 0.5-0.7% of the main purification water consumption, and then separated settling for 5-10 min. The loss of concentrate does not exceed 0.1%.

Deterioration of the quality of the filtrate with repeated use of auxiliary material is not detected.

The main advantages of the invention are the elimination of the need for special auxiliary filtering materials, which significantly reduces the cost of additional treatment, ensuring high filtration rates, as well as the possibility of multiple use of the auxiliary material while its regeneration is easy.

Claims (2)

1.Lukinykh N. A. Methods of wastewater after-treatment. M., stroiizdat, 1974, p. 16/38. 2.Razumovsky V. А. Additional purification of domestic wastewater of small settlements. Ob-, zorna information, ser. “Water supply and sewerage, M., Central Scientific Research Institute of Ministries of Agriculture of the RSFSR, 1978, vol. 2 (39), p. nineteen.