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UDC 628.16:62-278
SHVETSOV V. N., MOROZOVA K. M., FESENKO L. N., Kostyukov V. P., Vergunov A. I.
Biosorption-membrane reactor with flat filtering elements: the calculation method
Summary
The results of studying the Don River water purification with the use of biosorption-membrane method in a biosorption-membrane reactor with flat-frame filtering elements are presented. An experimental plant with a capacity of less than 2.7 m3/day with addition of powdered activated carbon was constructed at the Novocherkassk water treatment facilities. The specific flow through the membrane was less than 17.6 l/(m2·h). The experimental results showed the high efficiency of natural water purification in a biosorption-membrane reactor that provided for meeting the requirements of Sanitary Rules and Regulations (SanPiN). The efficiency of COD reduction averaged to 41.2%, color – 57.3%, permanganate value – 33.3%. During the entire experiment no suspended solids were found in permeate. The obtained data were used as a basis for calculating the specific rate of organics oxidation estimated by COD and permanganate value. The maximum values of Vmax oxidation rate and Km Michaelis constant were determined by graphical method of double reciprocal. The permanganate value dependence of the specific organics oxidation rate and COD from temperature was obtained. Temperature constant of Van Hoff’s equation was determined by COD and permanganate value to calculate the specific rate of organic pollutants oxidation during winter (10–11 °С) and summer seasons (20–22 °С). The method of calculating a biosorption-membrane reactor is presented.
Key words
powdery activated carbon , natural water treatment , biosorption membrane reactor , specific oxidation rate , biosorption , membrane filtration
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UDC 628.31:661.5
Stepanov S. V., Solkina O. S., MOROZOVA K. M., Stepanov A. S., Zhukova M. A.
The effect of membrane chemical washing on biological treatment processes
Summary
The results of research studies in the field of biomembrane treatment of dairy wastewater are presented. The experimental studies were carried out during four months. As a model effluent milk solution was used with addition of nutrients in the form of mineral salts – potassium monophosphate, ammonium chloride and sodium nitrate in ratios corresponding to the concentrations of these substances in original wastewater after physical and chemical treatment. The experiment was aiming at determining the process and kinetic characteristics of biological processes in a membrane bioreactor. The studies of the model wastewater in a pilot bioreactor showed that at 7–9 g/l sludge dosage and 0.36 m3/(m2·day) specific flow rate corresponding to the regular operation mode of flat-frame membranes the operation of the plant without chemical washing was possible for about two months. It was stated that membrane washing with citric acid at 1000 mg/l solution concentration (5–20 mg/l acid concentration in the membrane tank) provided for reducing the rate of biochemical processes with only mixed liquor acidification. The citric acid toxicity did not appear at mixed liquor pH in the range of 6.83–7.17. The study of membrane washing with sodium hypochlorite solution in concentration of 2000 mg/l as NaOCl showed the competitive inhibition of the organics oxidation rate with practically complete inhibition of biochemical processes at the active chlorine concentration in the reactor more than 26.1 mg/l. The time of restoring the original rate of organics oxidation at 6.6 mg/l active chlorine concentration in the reactor was 220 minutes after wastewater supply had been started and permeate had been removed.
Key words
biological treatment , membrane bioreactor , kinetic constant , dairy wastewater , membrane chemical washing , specific oxidation rate
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DOI 10.35776/VST.2022.12.05
UDC 628.35
Andreev Sergei, Stepanov S. V., Strelkov A. K.
Mathematical modeling of the wastewater biological treatment process in a plug flow aeration tank
Summary
The results of theoretical studies of the kinetics of the processes of biochemical oxidation of organic wastewater pollution by activated sludge microorganisms are presented. It is shown that the value of the average effective value of the specific rate of organic wastewater pollution oxidation by the activated sludge in a plug flow aeration tank can be determined using the theorem on the average value of the continuous function f(L) integrated in a certain range of its variable from Lн to Lк. By integrating the Michaelis–Menten equation, a mathematical model was obtained based on the fundamental regularities of enzymatic kinetics that describes the process of biological oxidation of organic pollutants in a plug flow aeration tank. The use of the proposed equations will provide for determining the average effective values of the specific oxidation rates of various organic pollutants (BOD, oil products, surfactants, phenols, etc.), the estimated duration of aerobic processes; and thereby, optimizing the design and operation of biological wastewater treatment facilities in plug flow aeration tanks.
Key words
activated sludge , complete-mix activated sludge system , specific oxidation rate , biochemical oxidation , enzyme kinetics , plug flow aeration tank
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DOI 000000
UDC 628.16:62-278
Vergunov A. I.
Removal of organic compounds from natural water
in a biosorption-membrane unit
Summary
The results of experimental studies on the purification of natural water of the Don River in a biosorption-membrane reactor equipped with flat-plate microfiltration membranes are presented. The research aimed at investigating the efficiency of the biosorption-membrane reactor operating with natural water with the subsequent determination of the kinetic characteristics of the running biosorption process. As a result of processing the experimental results, the efficiency of removing not only the turbidity and color of water, but also organic substances that caused high permanganate index and COD, was specified. The temperature constant was determined that provided for calculating the specific rate of oxidation of organic pollutants for the winter and summer seasons of the year. Using the obtained constants, it is possible to perform a design calculation of a biosorption-membrane reactor to any degree of purification required.
Key words
natural water , microfiltration , domestic water supply , biosorption membrane reactor , specific oxidation rate
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