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UDC 628.16.066.7
Boldyrev Vladimir Vasil'evich
Analytical model of sedimentation process based on the equation of continuity of settling polydisperse suspension flow (to be discussed)
Summary
In the well-known studies on the precipitation of polydisperse suspension the latter is identified with suspended (fluidized) bed. However all currently used mathematical models of natural and wastewater sedimentation processes do not take this circumstance into account and sometimes contradict it. Models of the processes of sedimentation in the strict sense have not yet been developed; instead separate methods are used with the help of which the process of sedimentation implemented in laboratory cylinders is carried out in industrial clarifiers. In this simulation the value of the main parameter of the sedimentation process (hydraulic size or sedimentation rate) always decreases with time. In the proposed model the flow of settling suspension is presented as fluidized bed. Moreover this flow has the properties of integrity and continuity of the values of its physical characteristics; whereas the flow rate in this case remains constant. In the process of the model design it was suggested that the concentration of suspended solids in the flow remained average by volume of the clarifier. Taking into account the continuity equation the sedimentation rate is proposed to be understood as the sedimentation rate of polydisperse suspension in the selected flow section that corresponds to the mass flow of suspension through the given section. Based on the above prerequisites a balance differential equation has been compiled that describes the process of sedimentation in a batch clarifier including laboratory cylinders. The solution of the differential equation provides for the formulas for calculating the clarification efficiency both for batch and flow-through clarifiers with time. In order to check the adequacy of the mathematical model the results of calculating the clarification efficiency using the obtained formulas were compared with the results of experiments carried out by other authors and with the typical project solutions. From the analysis of graphs it was concluded that the values of the clarification efficiency calculated theoretically have good convergence with the experimental data given in typical projects.
Key words
clarification , batch clarifier , flow-through clarifier , precipitation of polydisperse suspension , concentration of nonsettleable solids , clarification efficiency , analytical model , equation of continuity , balance differential equation
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UDC 628.16.004.69
Valuyskikh I. V., Mamaev V. V., Zhagin S. V., Boldyrev Viacheslav Viktorovich, Smirnov V. P.
Introduction of Up-to-Date Technologies of Potable Water Treatment
Summary
The modern conception of water treatment has been realized at the pumping-filtration station of 250 ths m3/day output supplying potable water to the left-bank part of the city of Novosibirsk. The scheme of water treatment includes preliminary water ammonization, the supply of coagulant (aluminum oxychloride) and flocculant, preliminary chlorination, mixing in a mixer of instantaneous action, preliminary flocculation, clarification in horizontal settling tanks, filtration at high-rate filters, secondary chlorination, UV-disinfection. The use of several technologies and technical decisions in the scheme of water treatment aimed at the ensuring of epidemiological safety and high quality of water makes this scheme exclusively reliable and universal.
Key words
chloramines , clarification , filtration , ultra-violet disinfecting , flocculant , flocculator , mixer , ammonization
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DOI 10.35776/VST.2022.10.04
UDC 544.77.052.22
Burganov Renat, Khasanova D. I., Gil’mutdinova Gul’fiia, Кирилова М. А., Kovrizhnykh E. A.
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
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UDC 628.162.5.001.2
Ganbarov E. S., Safarova A. S.
Treatment of Wash Water of Filters and Water Disinfection at Water Treatment Complexes of the Azerbaijan Republic
Summary
Results of studies carried out for determination of efficiency of clarification and investigation of influence of quantity and quality of the wash water supplied to a head of treatment facilities on the subsequent process of treatment are presented. For full disinfection of water it is proposed to use a disinfectant received by electrolysis of a solution of salts of alkaline metals and mineralized ground water directly at the territory of water treatment station.
Key words:
disinfection , wash water of filters , clarification , settling , filtration , reagent treatment
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UDC 628.161:536.22
Fomina V. F.
Features of Coagulation of Low Turbid, Color Water of the Vychegda Under Conditions of Low Temperature
Summary
Results of the reagent treatment of low turbid and color water of the Vychegda for the purpose of selection of the efficient method of its clarification is presented. The process of coagulation is characterized by the formation of small, poorly settling flakes. Low temperatures of water require increasing the optimal doses of coagulant almost two times and the optimal doses of flocculant more than two times. It is shown, that the water discoloration up to 5–10 degrees and its maximal clarification are achieved in and around of optimal pH values. The empirical dependences of a coagulant’s dose on influent water color with due regard for its temperature are given. The efficiency of low temperature water treatment depends substantively on flocculation process, the duration of which multiplies several times during the periods of water's low temperatures. Under these circumstances the pressure flotation is the most reasonable and efficient method of clarification.
Key words
clarification , chromaticity , flocculation , coagulant , flocculant , coagulation , alkalizing reagent , water temperature , pressure flotation
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UDC 628.162.15
Skolubovich Iurii, Voytov E. L., Karmalov A. I., Skolubovich Yu. L.
Treatment and Utilization of Wash Water of High-Rate Filters of Deferrization Stations
Summary
Issues of the intensification of coagulation treatment processes of wash water of the deferrization station’s high-rate filters are considered. Shortcomings of the existing flow chart of treatment and the reuse of wash water of filtration stations are exposed. The scheme of the unit and results of experimental studies for selection of an efficient reagent, treatment and utilization of filters’ wash water are presented. A new technology of reagent clarification and multiple use of deferrization station’s wash water is offered.
Key words
clarification , sedimentation tank , utilization , deferrization , coagulation , rapid filter , wash water
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UDC 628.33/.35:622
Maksimov E. A., Vasil'ev V. I.
Treatment of mining waters generated during gold ore extraction
Summary
The technologies used for treatment of mining waters generated during extraction of nonferrous and precious metals are considered. An industrial plant was designed that combined a multiple-tray clarifier and chemical treatment of mining water; the optimal operation mode with the aim of reaching the calculated parameters for designing treatment facilities was adjusted. An experimental plant for treatment of mining water at the Kochkar mine in Chelyabinsk Area was designed and tested. Aluminium sulfate, ferrous sulfate, ferric sulphide are recommended for the use as chemical agents. The recommended horizontal water flow velocity in the multiple-tray clarifier is 5–6 mm/s. The duration of water clarification with these velocities is 8-9 minutes, i.e. several times less than the sedimentation period in horizontal sedimentation tanks use in the traditional treatment technology. The suggested plant with the use of multiple-tray clarifiers provides for reducing the capital expenses for the mine treatment facilities compared to the traditional process flow scheme. At that the operation expenditures are reduced by 50–60%.
Key words
clarification , reagent treatment , coagulation , mining waters of gold ore , multiple-tray clarifier
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UDC 628.16.081.32
Shishov S. Yu., Troshkova E. A., Zhukova V. I., SMIRNOV A. D., Davlyaterova R. A., Smagin V. A.
Improving barrier functions of the Metelevskii water treatment facilities of Tumen city
Summary
The results of the preliminary tests showed that during the periods of elevated pollution of the water source (the Tura River) with different toxicants, natural and anthropogenic odorants the process flow scheme with the use of specially prepared powdered activated carbon for the conditions of the Metelevskii water intake would be worth considering. The process flow diagram of the pilot test facility was designed that provided for modeling the existing water treatment technology at the Metelevskii water treatment plant. The pilot facilities included chemical treatment units, clarification units, filtration and disinfection units. During water treatment process modeling the chemical dosages used (ammonium sulfate, chlorine, aluminium oxychloride and polyacrylamide) were similar to those at the Metelevskii water treatment plant for the moment the tests were carried out. According to the results of the tests the trademarks of powdered activated carbon used were defined as most efficient for odor and toxicant removal (by example of phenol). Before dosing into the water the sorbents were specially prepared (following the technique of NII VODGEO) to provide for maximum exhibiting sorption properties in relation to the mentioned target components. Special pilot equipment designed at NII VODGEO allowed reproducing all the water treatment modes applied at certain facilities. This modeling provides for adjusting water treatment technology, developing new process solutions, selecting new chemicals and dosages without interrupting the operation of the basic facilities. The results of the tests and pilot investigations with the use of powdered activated carbon at the Metelevskii water treatment facilities to remove anthropogenic toxicants and odors are presented. Powdered carbon trademarks were selected; recommendations for designing powdered activated carbon unit were given.
Key words
clarification , reagent , filtration , powdery activated carbon , organics , water treatment facilities , phenol , odor control
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UDC 628.345.9.001.9
Linnikov O. D., Rodina I. V.
Comparative efficiency evaluation of a number of known flocculants
Summary
The results of comparative evaluation of coagulating activity of a number of known flocculants at full identity of all basic factors that affect the process of suspended and colloid-dispersed solids are presented. The investigations were carried out in laboratory conditions with model suspension of titanium dioxide in tap water with average solid phase particle size of 4.5 µm. The known flocculants were tested to compare their efficiency. The following series was received: Nalco 8103 ≤ Nanofloc ≤ VPK-402 ≤ Praestol 611 = Praestol 2510 ≤ Praestol 853 ≤ Praestol 655 ≤ Praestol 2500 ≤ Praestol 650. Comparing the flocculant efficiency with a fixed dosage of 5 mg/l resulted in another series: Nalco 8103 ≤ Nanofloc ≤ Praestol 611 ≤ VPK-402 ≤ Praestol 2510 ≤ Praestol 853 ≤ Praestol 655 ≤ Praestol 2500 ≤ Praestol 650. It was suggested to use 5 mg/l dosage of the following flocculants in the process of water clarification: Nalco 8103, VPK-402, Praestol 650, Praestol 655, Praestol 853, Praestol 2500, and 10 mg/l dosage of Nanofloc, Praestol 611, Praestol 2510. It was noted that the ion activity of the flocculants did not affect much their coagulating capacity. In the carried out tests the efficiency of all the tested flocculants was almost an order lower compared to that of aluminium- and iron-containing inorganic coagulants. The received results of the investigations can be used in removing suspended solids from natural and waste water.
Key words
clarification , coagulant , flocculant , sedimentation , suspension , coagulating capacity
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