Studying and selecting effective flocculants for the purification of the Kama River water

Summary

Using the Kama River water as an example, the advantage of using flocculants of various ionic activity in combination with a coagulant based on polyaluminum chloride is shown. The results of studies of the main physical and chemical indicators are presented that better characterize the specific features of the coagulation of the Kama River water. Under the experimental conditions all tested flocculants were comparable as for the effectiveness to the flocculant based on polydiallyldimethylammonium chloride currently used at the water unit of Nizhnekamskneftekhim PJSC. In the process of water clarification using a flocculant (sample No. 1) was proposed with a dose of 1–3 mg/dm³. It was shown that the combined use of polyaluminum chloride and the flocculant (sample No. 1) was more effective for extracting aluminum ions from water. The method of river water coagulation with the use of the flocculant (sample No. 1) differs from the existing one in higher cost-effectiveness and 50–60% reduction the of the chemical consumption.

Key words

clarification , flocculation , coagulant , flocculant , efficiency of treatment , river water , residual aluminium , chemical dosage , polyaluminum chloride , polydiallyldimethylammonium chloride , test coagulation

DOI 10.35776/VST.2022.04.02
UDC 628.161.3:628.168.3

Seliukov Aleksandr, Raff P. A., Mishina T. F.

Pre-project in-process testing river water purification in the Arctic Circle

Summary

The results of pre-project in-process testing purification of water of the Vary-Khadyta River, the source of drinking and domestic water supply for the village of Yar-Sale (Yamal-Nenets Autonomous Okrug), are presented. Throughout the year the permissible concentration of iron, manganese, suspended solids and compounds in the river water that cause the water color is exceeded. Low temperatures, alkalinity and salinity result in the low level of water stability (Langelier index from –3.8 to –1.1 points). Water treatment facilities in Yar-Sale village (WTF-50) do not provide for the standard quality of purified water. This due to both incorrect water treatment technology that involves only filtration for clarification, and an incomplete set of chemicals required to produce drinking water. During the upgrade of the treatment facilities replacing the technology with the traditional clarification flow scheme (sedimentation – filtration) because of the periodic use of high doses of coagulant, as well as supplementing the chemical treatment with processes of alkalization and oxidation of the river water manganese with potassium permanganate was proposed. To assign the design modes of chemical water treatment, in-process tests were carried out under the conditions of the WTF of Yar-Sale village. For clarification and color removal, the chemicals used at the WTF of Yar-Sale village were applied (POHA «Aqua-Aurat-30^TM» coagulant, flocculant Praestol 2530). It is shown that using only these chemicals did not provide for the standard quality of drinking water. To enhance the efficiency of purification, it is proposed to carry out chemical treatment in two stages: upstream the sedimentation tanks – alkalization, coagulation and flocculation, then upstream the filters – additional alkalization, oxidation of manganese with potassium permanganate and additional flocculation. The operational doses of chemicals were determined, that ensure the production of stable drinking water meeting the requirements of the current regulatory documents. Based on the test results obtained, a standard operating procedure for designing the upgrade of the WTF-50 of Yar-Sale village was developed.

Key words

deferrization , potassium permanganate , demanganization , river water , stabilization treatment , soda ash , color removal , «Aqua-Aurat-30тм» , Praestol 2530

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UDC 628.113:624.131.41

Fomina V. F.

Water Humus Composition of the Vychegda River at Water Intake Site of the City of Syktyvkar

Summary

The Vychegda river is the main source of water supply for Syktyvkar. The water is characterized by low turbidity and high color, it contains ferrum and has low alkalinity and mineralization. During the autumn-winter period the water delivered to treatment facilities has a temperature of below 1 ºC. The swampiness of the river basin has an essential influence on water humus forming. The composition of humic substances adding the color to water is studied. It is defined, that fulvic acids compose the substantial part of humic substances. Color indices values for the main fractions of humic substances are defined. The influence of a seasonal composition and properties of humic substances and temperature conditions on water coagulation is proved.

Key words

suspended substances , chromaticity , flotation , humus , coagulant , filtration , river water

DOI 10.35776/VST.2021.11.06
UDC 628.168:628.166-926.214

Seliukov Aleksandr, Semenov Mikhail, Baikova Ida

In-process tests of river water conditioning for domestic and drinking water supply in the city of Kurgan

Summary

The experience of using ozonation of river water on a laboratory and pilot scale is considered. The water of the Tobol River is hard and mineralized with an average color value of 24 degrees, a manganese concentration in the winter period of more than 0.8 mg/dm³. After determining the operational doses of the chemicals (polyaluminum chloride coagulant, Praestol 650TR flocculant), test ozonation was carried out followed by the chemical treatment in a laboratory flocculator. To achieve the standard for manganese concentration in river water of 0.1 mg/dm³, high doses of ozone were required – from 35 mg/dm3. Alkalinization of the initial water to pH 9 provided for reducing the ozone dose to 23 mg/dm³. A decrease in color to 15 degrees occurred at ozone doses of 6–7 mg/dm³. River water purification at a pilot plant with a capacity of 50 l/h was carried out according to the complete process flow scheme (ozonation, treatment with coagulant and flocculant, sedimentation, filtration in a sand filter, filtration in a carbon filter, desalination-softening by reverse osmosis). The coagulant dose was 5 mg/dm³, and that of the flocculant – 0.3 mg/dm³. In the steady run of the pilot plant at an ozone dose of 25 mg/dm³, the following quality indicators of the sand filter filtrate were achieved: color 5–7 degrees; manganese 0.05–0.15 mg/dm³; total iron 0.02–0.03 mg/dm³; aluminum 0.05–0.08 mg/dm³; permanganate index 3–4 mg/dm³. Based on the estimate indicators of the Tobol River water composition related to the manganese concentration in water of 0.8 mg/dm³, the theoretic dose of ozone is ≈ 8 mg/dm³, the design dose of ozone can be assumed as 10 mg/dm³ (g/m³).

Key words

ozonization , water supply , chromaticity , manganese , river water

DOI 10.35776/VST.2022.02.02
UDC 628.16.067.3:581.526.325

Kevbrina M. V., Gavrilov Dmitrii, Stolyarova E. A., Strikhar Yu. V., Agarev Anton, Klimova Nataliia

Efficiency of microfiltration in disk filters with plane and volume filtration in the process of removing phytoplankton from water from surface sources

Summary

«Mosvodokanal» JSC has completed testing DynaCloth automatic self-cleaning fiber disc microfilter for the Moskva River water. The tests were carried out during the periods of intensive phytoplankton growth eliminating the use of chemicals. The filtration surface area of the filter was 0.45 m². At 4–8 m³/h water flow rate the hydraulic load was 9–18 m/h. Wash water flow was 1.1–3.3% of the water flow in the unit depending on the type of the filter cloth. Different types of algae dominated in the Moskva River water in different periods. In general, at the peak diatom number their concentration during filtration decreased less than by 53%. The decrease in the number of green algae at the peak of their growth occurred by 56–60%, and that of blue-green algae – by 36%. Cells of diatoms and green algae coenobia are larger than blue-green cells; accordingly, the efficiency of their capture by the filter was higher than that of blue-green algae. The results of the studies carried out for the Moskva River water showed that microfiltration in disk filters with fiber filter cloth can be a promising method for removing phytoplankton (about 50%) from low-turbid eutrophicated waters.

Key words

phytoplankton , river water , microalgae , disk filtration , disk fiber microfilter

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