bbk 000000
UDC 628.16
Fomina V. F., Fomin A. V.
Upgrade of horizontal sedimentation tanks with the use of dissolved-air flotation
Summary
The analysis of the efficiency of low turbidity colored water of the Vychegda River purification at the water treatment facilities of Syktyvkar in horizontal sedimentation tanks operating in the mode of coagulation at 2–3 times lowered hydraulic loading is presented. The necessity of upgrading the sedimentation tanks by redesigning their exit sections into flotation chambers is substantiated. The enhancement of the sedimentation tank operation by equipping with a flotation chamber provides for meeting the regulatory requirements to the drinking water quality under the conditions of significant seasonal fluctuations of the raw water quality indicators and temperature. Enhanced clarification of the water being coagulated is ensured before the filtration stage; at that the flow rate of backwash water decreases 3 times, the number of filter washes per day decreases to 0.5 times and less (filter run increases to 2 days and more). Backwash water purification together with raw water provides for streamlining the process flow scheme and chemical facilities (the number of chemical injection and dosing points decreases); facilitating the operation of the facilities, 8% operational expenses saving and plant demand decreasing to 3%. The upgrade of horizontal sedimentation tanks with the use of dissolved air flotation is more economically and environmentally feasible than the reconstruction of the two-stage filtration facilities. It provides for doubling the sedimentation facilities output, decreasing the amount of wash water and combined with raw water handling.
Key words
wash water , horizontal settling tank , filtration , pressure flotation , low turbidity colored water , hydraulic loading , water treatment plant
|
bbk 000000
UDC 628.16.069
Kofman V. Ya.
Dissolved-air flotation in water treatment (a review of foreign literature)
Summary
A review of foreign literature on one of the perspective water treatment technologies, i. e. dissolved-air flotation, is presented. The process of dissolved-air flotation provides for decreasing water turbidity, eliminating algae, Giardia cysts and Cryptosporidium oocysts; whereby, the treatment efficiency is higher compared to sedimentation. The technology ensures efficient removal of low turbidity levels. Overseas, beyond controversy, the tendency of using dissolved-air flotation units for purification of water and wastewater of different origin is increasing.
Key words
water treatment , efficiency of treatment , pressure flotation , hydraulic loading
|
DOI 10.35776/VST.2022.02.04
UDC 628.3:533.54
Andreev Sergei, Stepanov S. V., Stepanov A. S., Kniazev Vladimir
New process flow scheme for wastewater treatment by pressure flotation
Summary
The results of calculating a circulation unit for converting the Q–H-characteristics of an impeller pump with the withdrawal of the useful fluid flow upstream the waterjet pump are presented. Mathematical dependencies are obtained that adequately describe the process of the operation of the circulation unit for the conversion of the Q–H-characteristics of an impeller pump. It has been theoretically substantiated and experimentally proved that replacing a high-pressure waterjet pump in the circulation unit with two sequentially operating medium-pressure waterjet pumps ensures the sustainable atmosphere air ejection and reliable operation of the pressure flotation unit, provided the hydraulic efficiency of the circulating unit is reduced from 42 to 33% and the useful flow rate Qн decreases slightly. The proposed process flow scheme of pressure flotation that involves the use of a circulation unit to convert the Q–H-characteristics of an impeller pump with two medium-pressure waterjet pumps operating in series, provides for abandoning the use of an expensive compressor and replacing a high-pressure impeller pump with a cheaper pump with lower operating pressure.
Key words
wastewater treatment , pressure flotation , impeller pump , waterjet pump , circulation unit , coefficient of ejection , relative pressure drop
|
bbk 000000
UDC 628.16.081
Fomina V. F., Fomin A. V.
The experience of operating pressure flotation facilities for the purification of low-turbid colored water of the Vychegda River (on the occasion of 10 years of the startup of pressure flotation facilities
at the water treatment plant of Syktyvkar)
Summary
The results of operating the pressure flotation facilities with a capacity of 65,000 m3/day commissioned in May 2006 at the water treatment plant of Syktyvkar are considered. During 10 years the pressure flotation facilities have been successfully operating and ensuring high-level clarification of drinking water. The analysis of the main water quality indicators after each treatment stage showed that the pressure flotation method had been the most efficient for purification of low-turbid colored water of the Vychegda River. It is stated that during certain seasons color increase higher than 150–200 grades and temperature decrease result in complications with meeting the standard for permanganate oxidizability; therefore more detailed selection of chemical agents and dosage optimization is required. At the optimal coagulation operation mode the method of pressure flotation provides for enhanced water clarification to less than 1 mg/l turbidity which allows using filters as barrier facilities in case of turbidity breakthrough.
Key words
reagent treatment , coagulation , wash water , filtration , pressure flotation , low turbidity colored water
|
bbk 000000
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
|
UDC 628.54:676
Feofanov Yu. A., Tarasenkov Viktor, Cherniat’ev Anatolii
Specific features of paper mill wastewater treatment
Summary
The results of the operation of local and all-factory wastewater treatment plants of a separately located paper mill using waste paper and cellulose as raw materials are considered and analyzed. The following characteristic features of the factory wastewater are indicated: significant fluctuations in flow rate and composition, high concentration of organic matter, elevated temperature, etc. The conditions for the effective operation of the local treatment facilities, including chemical treatment and two-stage pressure flotation when using waste paper and cellulose as raw materials, are noted. The unit costs and amount of effluent pollution discharged after local treatment have been determined. The data on the efficiency of the all-factory biological treatment facilities including a moving-bed bioreactor and aeration tanks, are presented. Dependencies of the main process parameters of the facilities have been obtained that provide for predicting the treatment efficiency. Measures are proposed to improve the operation of local facilities and biological wastewater treatment facilities of a paper mill.
Key words
reagent treatment , wastewater , bioreactor , aeration tank , pressure flotation , local treatment facilities
|
bbk 000000
UDC 628.35.004.1
Boichenko A. A., Miasoedov A. IU., Syrnikov E. V.
Flotation treatment of phenolic wastewater in a biochemical unit of the coke and by-product process
Summary
In 2014 the construction of a unique unit for biochemical treatment of wastewater from coke and by-product process at the «Novolipetsk Steelworks» OJSC was finished. EKOTON flotation units used in the process of removing tar and oils from the recycling phenol wastewater have been specially designed for the application in this industry and provide for 97.5% treatment level in relation to the main parameters. The results of the laboratory studies and full-scale tests of phenolic coke wastewater treatment by chemical dissolved air flotation are presented. The specialists of «EKOTON» Company have selected the parameters of the process equipment and improved the design of the flotation unit; determined the main parameters of physical-and chemical treatment of phenolic wastewater with due account for the wastewater composition, high temperature, limits of the tar and oil concentrations in the mixtures discharged from the flotation unit. The experimental data allowed developing the regulations for operating flotation units for coke and by-product process with the use of chemical treatment of phenolic wastewater. The novelty and singularity of the treatment processes introduced at the wastewater treatment facilities of «NMLK» OJSC provided for installing the completely sealed utilities and tanks above the ground to eliminate any possible underground water pollution and reduce air emissions. In 2015 after industrial-scale testing «EKOTON» flotation unit was commissioned as a part of the biochemical unit of the coke and by-product process.
Key words
coagulant , flocculant , pressure flotation , coking plant , biochemical treatment unit , flotation unit , phenolic water
|
bbk 000000
UDC 628.16.069
Fomina V. F., Fomin V. P.
The efficiency of low turbidity colored water treatment in dissolved-air flotation units
Summary
In order to ensure high quality drinking water at the Syktyvkar water treatment plant for the entire lifecycle of the facilities a number of process lines were constructed with different combinations of the primary treatment facilities: horizontal settling tanks, contact primary filters, dissolved-air flotation units. The treatment line with dissolved-air flotation with a capacity of 65,000 m3/day was commissioned in 2006. The evaluation of the plant efficiency during the commissioning and follow-up operation periods is given. The advantages of using the dissolved-air flotation technology for low turbidity colored water treatment in comparison with the operation of other treatment lines are given. The efficiency of coagulated water flotation clarification is comparable with filtration.
Key words
pressure flotation , low turbidity colored water , flotation clarification
|
bbk 000000
UDC 628.33:551.577.21
Gandurina L. V., Andriyash E. N., Lovlin V. M.
The efficiency of flotofloculation treatment of industrial storm oil effluents
Summary
The results of industrial-scale operation of flotoflocculation plant for industrial storm oil effluents treatment in КWI (Austria) dissolved-air flotation unit with the addition of Praestol 853 cationic flocculant are presented. It was shown that the efficiency of wastewater treatment in the terms of residual oil concentration can be ensured at the initial oily waste concentration as high as 1300 mg/l and flocculant dosage of 5.5 mg/l.
Key words
oil products , wastewater , pressure flotation , cationic flocculant
|
|
