Use of Graphene Sorbent in Filters for Cleaning Surface Water and Hot Water

Abstract

The technology of producing foamed (thermoexpanded) graphite in the form of anisotropic particles with a size of about 100 microns and a thickness of about 5 atomic layers has been developed. The BET surface area of 12–15 m²/g, the calculated surface area at a thickness of 1,5 nm is about 800 m2/g, which allowed it to be used in filters for drinking water purification. Water testing of Lake Ladoga showed that even after 500 m³ of filtered water the turbidity did not exceed 0,5 mg/l, chromaticity 13 degrees, iron 0,11 mg/l and oxidizability 3,1 mg O/l. At the same time, the resource for turbidity and iron is not yet exhausted. The advantages of the sorbent GS are shown in the example of hot water treatment. In the Ice Palace of St. Petersburg a system of two filters "Hercules" was designed to clean hot water to fill the ice cover of the ice rink, instead of filtering the cold water and then heating it, which saved more than 3 million rubles a year. To improve filter performance, a new design was developed and tested, characterized in that it is not made in the form of a traditional cartridge, but is a backfill. The drop in the performance of such a filter to a critical level of 1,2 m³/h occurs with a filtration of 480 m³, which is 4 times greater than the volume of water obtained from the coaxial design of the filter (120 m³). Filters with uneven compaction of GS are proposed to be used for cleaning surface water in the manufacture of a modular mobile unit with a capacity of up to 10 m³/h, which is designed to produce drinking water in populated areas where there are no coagulation plants and it is impossible to reach a water conduit with drinking water, Collections, youth forums and in cases of disasters.