bbk 000000
UDC 628.31:614.71
Kolycheva M. A.
Controlling malodorous emissions of wastewater treatment facilities
Summary
Wastewater treatment facilities feature malodorous emissions into the atmosphere that result from the process of wastewater treatment and contain mercaptans, hydrogen sulfide, ammonia, amines etc. The preventive measures against negative impact of malodorous emissions on the urban development include two stages: collection of the polluted emissions and their subsequent purification. Preventing emissions into the atmosphere and collecting gases are carried out by installing covers on the aeration facilities. The advanced and technically perfect method of air purification is used in «Iatagan» gas converters. The principle of «Iatagan» units operation is based on the combined effect of bulk barrier-streamer discharge and ozone on the molecules of hazardous and malodorous gases. The use of «Iatagan» gas converters is the best solution of the air purification problem at the wastewater treatment facilities.
Key words
air cleansing , sewerage treatment facilities , malodorous emissions , ozone , gas converter
|
UDC 628.161.2:544.77.052.5:628.16.094.3-926.214
DOI 10.35776/VST.2023.02.07
Pilipenko Marina, Dubina Aleksandr, Likhavitskii Vitalii
Combining ultrasonic treatment and ozonation for wastewater treatment of dyeing plants
Summary
The results of studying the efficiency of purification of model and real wastewater from dyeing and finishing works by combining ultrasonic treatment and ozonation are presented. The effect of the treatment time, ozone concentration in the gas mixture on the purification efficiency has been studied. The purification efficiency was evaluated by optical density and COD. As a result of the study up to 12% increase in the efficiency of wastewater treatment was shown while combining flotation with ozone-air mixture instead of air with ultrasonic treatment. This effect can be associated, first of all, with the dispersion of ozone-air mixture bubbles that results in an increase in the surface area, and, accordingly, in an increase in the kinetics of mass transfer – ozone dissolution.
Key words
flotation , wastewater , dye , ozone , fabric dyeing
|
UDC 628.237.2:628.521
DOI 10.35776/VST.2024.06.06
Vasiliak L. M., Sobur Denis
Why is ozone not used in world practice to control odors
from the wastewater disposal system?
Summary
The reasons that limit possible using ozone to remove hydrogen sulfide and other malodorous substances coming from the wastewater treatment facilities and wastewater pumping stations are analyzed. It is shown that one of the main disadvantages is the long time required to remove malodorous substances to the required low concentrations. The main reaction of ozone interacting with hydrogen sulfide is presented, its rate is analyzed, and it is shown that the typical duration of the reaction ranges from tens of minutes to several hours. The difficulties of using ozone to remove hydrogen sulfide, associated with the chemical resistance of the latter, are presented. The ozone concentrations required for the effective cleaning, and the number of ozone molecules consumed to remove one hydrogen sulfide molecule are estimated. Data are provided on the use of ozone to remove volatile organic compounds, including phenol and formaldehyde. Issues related to the disposal of reaction products and safety precautions of ozone use are also discussed.
Key words
ozonization , air cleansing , sewerage treatment facilities , hydrogen sulfide , ozone , odors
|
DOI 10.35776/VST.2022.09.06
UDC 628.316
Belov S. G., Naumchik G. O.
The use of ozone to reduce the color intensity of textile wastewater
Summary
The relevance of the development of effective methods for the destruction of dyes in the wastewater of consumer goods industry is increasing due to the severization of the requirements to the aquatic environment protection. The mechanisms of interaction of ozone with unsaturated and aromatic organic compounds in aqueous solutions are considered. Special focus is placed on the interaction of ozone with azo dyes. A detailed procedure for carrying out experimental studies is given, that provide for accurate dosing of ozone into the reaction mixture. The data of experimental studies are presented that are indicative of the effectiveness of using ozone for the destruction of dyes in model solutions. A comparison was made of the effectiveness of using ozone compared to the reducing agents to reduce color intensity of dye solutions. Specific doses of ozone have been preliminarily determined to reduce color intensity of solutions of some synthetic dyes to standard values.
Key words
wastewater , ozone , textile industry , azo dyes , color intensity
|
DOI 10.35776/VST.2023.01.06
UDC 544.526:628.169
Pilipenko Marina, Dubina Aleksandr, Likhavitskii Vitalii
Flotation of wastewater from dye works using ozone
Summary
The results of experimental studies of the efficiency of purification of model and real wastewater from dye and finishing works with the aid of pneumatic flotation using ozone-air mixture instead of air are presented. The effect of the gas mixture flow rate, dye concentration, and ozone concentration in the gas mixture on the purification efficiency was studied. The purification efficiency was evaluated by optical density and COD. While using ozone-air mixture instead of air, a 12-fold efficiency increase was achieved. The results of the studies have shown that while using ozone flotation to achieve the purification efficiency of 90% of the real wastewater from dye and finishing works, abstracted upstream the treatment facilities (electrocoagulation followed by flotation), the following conditions are required: processing time not less than 60 minutes; consumption of ozone-air mixture not less than 5 l/(l·min); ozone concentration in the ozone-air mixture not less than 8 g/m3.
Key words
wastewater , flotation , dye , ozone , fabric dyeing
|
|
