Optimum technological parameters of new filter materials for the preparation of drinking water

Abstract

Goal. To determine the efficiency and optimal technological parameters of new filter materials and sorbents intended for cleaning natural surface waters. Methods. Empirical (for conducting laboratory studies), analytical comparison (for determining the efficiency of sorbent deposition), and mathematical statistics (for building models of cleaning efficiency based on the turbidity index). Results. It was established that in the case of pre-treatment of water with the use of polystyrene foam loading, the highest efficiency was 44% at a filtration speed of 10 m/h, and the optimal parameters were the diameter of polystyrene foam granules of 5–8 mm and the thickness of the filter loading of 1.5 m. In the case of additional water purification, the efficiency of the polystyrene foam filter was 60–80%, the efficiency of the zeolite filter was 50–65%, and the optimal parameters were the diameter of the polystyrene foam granules of 2–5 mm and the height of the filter load of 0.8–1.0 m. The combination of pre-cleaning and post-cleaning polystyrene foam filters ensured turbidity cleaning efficiency of 70–80%, and color — up to 50%. A mixture of bentonite with copper ferrocyanide provided better adhesion of contaminants — it significantly accelerated the formation of flakes and their precipitation, without reducing the effectiveness of the sorbent. The best effect in the case of 137Cs sorption from the model solution was observed when using copper ferrocyanide: all its concentrations, including the minimum of 0.1 g/l, ensured the removal of 137Cs beyond the lower sensitivity limit of the «ATOLL-3M» gamma-ray spectrometer. Conclusions. The expediency of using new filter materials — zeolite and expanded polystyrene and sorption materials — powdered zeolite, bentonite, and copper ferrocyanide for the purification of natural waters was established, and their efficiency and optimal technological parameters were determined.