The experience of using peat filtration for surface runoff treatment

Summary

The 20-year experience of using peat filtration technology for surface runoff treatment has been described. The advantages of the technology are given; the simplicity of operation in a large range of surface wastewater amount is noted. The choice of treatment technology and filtering materials is a rather complicated task, since it requires achieving effective purification at minimum cost and without using extra electricity. The natural origin of peat, its availability, good filtering properties, ease of disposal and low cost determine the preference of its use in surface runoff treatment technologies. In the period 1994–2018 a group of companies developed a system for passive mechanical treatment of surface runoff using peat filtering materials. At the facilities of the North-West Federal District of the Russian Federation more than 900 systems for the purification of surface runoff of various amounts were introduced including more than 300 on the R-21 Kola highway and large Pulkovo-3 facilities with a capacity of 700 m³/h in St. Petersburg. The absence of the need to use electricity even in minimal amounts has provided for the efficiency of such technologies. The widespread introduction of peat filtration can be attributed to the best available technologies.

Key words

surface runoff , efficiency of treatment , peat filtration , filtering material

Comparative analysis of the physicomechanical properties
of natural materials used as filter media

Summary

The results of the study of physicomechanical properties of filtering materials – crushed expanded clay with a bulk density of 525 and 555 kg/m³ and Diamix AQUA with a bulk density of 670 kg/m³ are presented. Easy upheaving clays of a certain chemical and mineral composition serve as raw materials for expanded clay production, for Diamix AQUA production raw material based on natural diatomite that includes exoskeletons of diatoms is used. Oxide concentration in Diamix AQUA is: SiO₂ more than 83%, Al₂O₃ less than 6% and Fe₂O₃ less than 3.5%. Diamix AQUA filtering material has a National Registration Certificate. The research results showed that the new filtering material based on Diamix AQUA can be used as media for newly constructed filtration facilities. To regenerate the filter media, an increased backwashing rate is needed, which requires checking the throughput of the filter drainage and distribution system to pass through the increased water flow rate.

Ключевые слова

water treatment , filtering material , bulk density , apparent specific gravity , physical integrity , backwash rate

Filtering materials for the domestic water supply

Summary

The results of laboratory and pilot tests of the following filtering materials used for water purification in a domestic water supply system: Diamiks Akva, granodiorite sand, ODM-2F and ODM-5F are presented. The manufacturers of the filtering materials are indicated. The basic chemical composition of the filtering materials is given. The raw material for Diamiks Akva is based on natural diatomite that contains exoskeletons of diatoms. The poured bulk density of Diamiks Akva is 820 kg/m³. Granodiorite sand is a product of crushing granodiorite rock with a poured bulk density of 1498 km/m³. For ODM-2F opokas from the Artemovsk deposit in the Sverdlovsk region with a poured bulk density 680 kg/m³ are used. ODM-5F is a sorption material prepared on the basis of siliceous diatomaceous earth (kieselguhr, tripolith and diatomite) with a poured bulk density of 700 mg/m³. The studied filtering materials have the certificates of registration. The results of studying the physical and mechanical properties of filtering materials are presented; the granulometric composition is given, the intensity of washing depending on the degree of expansion is established. The research results showed that filtering materials made of Diamiks Akva and granodiorite sand can be used as media in newly constructed filtering facilities. Higher washing intensity is required for the regeneration of the specified filter media. ODM-2F and ODM-5F filtering materials do not involve higher costs during the regeneration of the media since the drainage and distribution systems of rapid filters provide for the capacity of the washing flow.

Key words

filtering material , bulk density , physical integrity , backwash rate , porosity , domestic water