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UDC 628.35
Stepanov S. V., Stepanov A. S., Gabidullina L. A., Dubov O. V.
Biological treatment of oil refinery wastewater in a biosorption membrane reactor
Summary
The basic process and kinetic regularities of biomembrane and biosorption membrane treatment of fuel and lube refinery wastewater are presented. The enhancement of denitrification process is suggested by reducing the dissolved oxygen concentration in the circulating flow of activated sludge by vacuum treatment. Summarizing the results of operating a pilot vacuumizing unit the more efficient use of biosorption membrane technology compared to the biomembrane method is shown. Single dosing of 1 g of powdered activated carbon per 1 liter of mixed liquor provided for reducing the mean monthly concentration of pollutants in permeate: in COD – from 68 to 49 mg/l; in BODfull – from 6 to 3.5 mg/l; in oil products – from 0.65 to 0.21 mg/l. The kinetic constants of the processes of eliminating the basic pollutants in membrane and biosorption membrane reactors were determined. It was stated that the specific oxidation rate in biosorption membrane reactors exceeded the similar indicators of membrane bioreactors only for easily sorbed substances – oil products and organic pollutants evaluated in BODfull. Vacuum treatment of circulating activated sludge during 5 minutes at minus 90 kPa pressure in a membrane bioreactor provided for 2-fold reduction of the dissolved oxygen concentration, improvement of the sedimentation properties of activated sludge (compared to the flow scheme without vacuum treatment) and the dissolved oxygen concentration less than 0.5 mg/l in the anoxic zone of the membrane bioreactor.
Key words
wastewater , nitrification , activated sludge , membrane bioreactor , denitrification , oil refinery , kinetic constant , activated carbon , biosorption membrane reactor
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UDC 628.35:661.5
Strelkov A. K., Stepanov S. V., Blinkova L. A., MOROZOVA K. M., Belyakov A. V.
Investigating the processes of single-stage biological treatment
of oil refinery wastewater
Summary
The results of investigating the operation of the Novokuibyshevsk oil refinery waste biological treatment facilities are presented. It was found that denitrification process was not possible in two-stage process of wastewater treatment because of
high concentration of dissolved oxygen in the denitrification tank and low concentration of organics in raw wastewater. Full-scale experiment with single-stage mode of operation of the entire biological treatment facilities was carried out. After the first-stage aeration tanks de-commissioning the total activated sludge amount in the system increased almost 1.5-fold. Sludge concentration in the aeration tanks (of the second stage) increased from 0.5–1 to 2–2.5 mg/l; COD sludge load was reduced from 143 to 77 mg/(g·day). The improved nitrification efficiency and denitrification start were recorded. Kinetic constants were determined for the processes of organics and oil products oxidation, for nitrification and denitrification required for designing wastewater treatment facilities with nitrification-denitrification technology. Inhibition by substrate was found at the concentration of oil products in effluent higher than 4 mg/l. Nitrification inhibition was observed at ammonia nitrogen concentration in effluent higher than 1 mg/l. The full-scale experiment of conversion of the Novokuibyshevsk oil refinery waste biological treatment facilities to one-stage operation provided for testing on commercial scale the advanced nitrification-denitrification technology and recommending this process flow scheme for the introduction at other RF oil refineries.
Key words
wastewater , biological treatment , nitrification , denitrification , oil refinery , kinetic constant
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UDC 628.35:661.5
Stepanov S. V., SHVETSOV V. N., MOROZOVA K. M., Belyakov A. V., Blinkova L. A.
Investigating nitrification-denitrification technologies of oily wastewater treatment
Summary
The results of investigating biological treatment by nitrification-denitrification technology of oily wastes of the Novokuybyshevsky oil refinery are presented. Possible meeting the advanced requirements to the effluent quality in relation to nitrogen compounds, particularly, by industrial wastewater treatment without blending with municipal wastewater is shown. The kinetic constants of nitrification-denitrification processes and oxidation of oil products required for designing wastewater treatment facilities are determined.
key words
wastewater , biological treatment , nitrification , denitrification , oil refinery , kinetic constant
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UDC 628.35:665.6
Stepanov S. V., Strelkov A. K., Blinkova L. A., MOROZOVA K. M., Belyakov A. V.
Estimating kinetic constants for the process of biochemical treatment of oil refinery wastewater
Summary
The results of studies carried out under periodic conditions at the wastewater biological treatment facilities of the Novokouibyshevsky, Kouibyshevsky, Syzransky and Atchinsky oil refineries are presented. With reference to the measured oxygen consumption rate the values of the maximum oxidation rate, Michaelis constants and coefficient of inhibition by activated sludge degradation products were obtained. Kinetic constants depend on the raw wastewater composition and are subject to daily fluctuations. The obtained values can be used in designing aeration tanks for oil refinery wastewater treatment.
Key words
wastewater , biological treatment , activated sludge , oil refinery , kinetic constant
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UDC 628.35:661.5
Stepanov S. V.
Specific features of designing oil refinery wastewater biological treatment facilities
Summary
Oil refinery wastewater is characterized by the presence of organics resistant to oxidation and practically total absence of phosphorus. The procedure of designing oil-containing wastewater biological treatment with nitrification-denitrification is used both for aeration tanks and membrane bioreactors. Designing is carried out with the use of kinetic relationships for all the regulated pollutants. During the experiments kinetic constants and coefficients of nitrification and denitrification processes, oxidation of organic substances (as BOD and COD), oil products, phenols and synthetic surfactants for wastewater of a number of oil refineries were obtained. Calculations algorithm includes the following stages: determining initial data – pollutant concentrations and wastewater flow rates; choosing the process flow scheme of the treatment facilities; calculating specific rate of biological treatment process on the basis of kinetic constants and coefficients; calculating activated sludge growth, nitrogen and phosphorus losses in the process of assimilation; estimating the retention time for oxidation of separate ingredients of pollutants and denitrification; determining the maximum aerobic process time in respect to the limiting component and treatment level in respect to other ingredients; calculating the required air consumption; checking the necessity of dosing phosphorus compounds for nutrient makeup. To improve the denitrification efficiency the configuration of the facilities was enlarged with a mixed liquor deaerator. The process design of a membrane bioreactor differs from the design of aeration tanks with nitrification-denitrification by correction of specific oxidation rate with account of the obtained kinetic constants and coefficient of inhibition with metabolism products at higher concentrations of activated sludge in the bioreactor. The experimental results allowed supplementing the procedure of designing wastewater biological treatment facilities with nitrification-denitrification developed by NII VODGEO.
Key words
wastewater , biological treatment , nitrification , activated sludge , membrane bioreactor , denitrification , oil refinery , kinetic constant
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UDC 628.35:661.5
Stepanov S. V., Gabidullina L. A., MOROZOVA K. M., Stepanov A. S., Sokolova T. V.
Evaluation of the impact of wastewater from separate oil refining units on biological treatment process
Summary
The composition and kinetic characteristics of biochemical oxidation of separate wastewater flows from oil refining process units is determined. The study subject was wastewater of the Novokuibyshevsk oil refinery – fuel and lube refiner. In order to evaluate separate wastewater flows with different biological degradability, a kinetic method under contact conditions was used, i. e. the method of recording variations in time of dissolved oxygen concentration followed by determining the oxygen uptake rate depending on the concentration of substrate or other factors. It was stated that the significant part of wastewater from oil refining process units was inhibiting the process of biological treatment of the entire wastewater flow of the refinery. The experimental determination of the inhibition constants of enzyme kinetics equations is of great practical interest because it provides for evaluating the toxic flow impact on the process rate, and what is more determining the type of inhibition. Knowing the inhibition type the ways of eliminating inhibition can be determined which is equally important in biologcal treatment of toxic wastewater. The general methods of eliminating any type of inhibition in the process of oil refinery wastewater biolological treatment is decreasing the toxic flow part in the total flow, i. e. flow rate equalization and activated sludge concentration increase in the facilities. Flow and pollution concentration equalization will prevent from the disturbance of biological treatment processes related to volleys of such wastewater. The last confirms the technological expediency of using membrane bioreactors for biological treatment of oil refinery wastewater that allow operating under the conditions of complete activated sludge retention the the reactor.
Key words
wastewater , biological treatment , oil refinery , kinetic constants and coefficients , competitive inhibition , uncompetitive inhibition , substrate inhibition
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DOI 10.35776/VST.2021.03.07
UDC 628.316.12:628.52
Gimaletdinov Rustem, Usmanov Marat, Valeev Salavat, Bodrov Viktor, Paskaru Konstantin, Vezhnovets Viktor
Sorbent based on modified hydrolysis lignin for the purification
of wastewater from oil refineries
Summary
The results of studies of using SynergySorb® PS-1000 sorbent based on modified hydrolysis lignin for the purification of wastewater from large oil refineries are presented. Owing to the developed system of micro- and mesopores, the sorbent effectively absorbs light fractions of hydrocarbons, thus reducing the total content of oil products in wastewater and the intensity of odor near open treatment facilities. The total dynamic exchange capacity of the sorbent for oil products was 0.605 g/g while filtering wastewater from one of the largest Russian oil refineries. The average treatment efficiency before the breakthrough of oil products was 94%, the intensity of effluent odor as a result of tests was reduced from 5 to 2 points. Spent SynergySorb® PS-1000 sorbent belongs to the 4th hazard class (low hazard) in terms of toxicity and ecotoxicity.
Key words
filtration , wastewater , odor , oil refinery , sorbent , sorption treatment , lignin , очистка от нефтепродуктов , dynamic sorption capacity
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