bbk 000000
UDC 628.349.08
Strelkov A. K., Stepanov S. V., Stepanov A. S., Andreev Sergei, Iakhkind M. I.
Study of the processes of electrochemical synthesis of alkaline oxidizing agent – sodium ferrate
Summary
Internationally in the process of purifying industrial wastewater containing organics resistant to oxidation advanced oxidation technologies that provide for the use of oxidizing agents that possess extended oxidizing potential are gaining around. Alkaline sodium ferrate solution is one of the most active oxidizing chemicals. Laboratory studies were carried out to investigate the process of sodium ferrate production by electrolytic treatment of strong sodium hydroxide solution (30–40%) in a membrane electrolyzer with a steel anode. It is shown that in the process of 40% solution of sodium hydroxide activation in the membrane electrolyzer with the laminar steel anode for five hours (anode current density 100 А/m2, specific quantity of electricity 20.5 A.h/l) the concentration of sodium ferrate in the anolite reached 7.2 g/l. The current efficiency of sodium ferrate output changed from 0.54 during the starting period of the electroactivation treatment to 0.28 at the end of the process. It was determined experimentally that during the storage of sodium ferrate for seven days its concentration in 40% sodium hydroxide solution dropped from 7.2 to 1.8 g/l. The use of sodium ferrate, alkaline oxidizing agent possessing extended oxidizing potential in the process of industrial wastewater disruptive treatment will provide for the significant reduction of resistant to oxidation organics present in it.
Key words
industrial wastewater , physical and chemical treatment , sodium ferrate , membrane electrolyzer , поверхностный сток , electroactivation , sodium hydroxide
|
UDC 628.35
DOI 10.35776/VST.2023.05.05
Stepanov S. V., Avdeenkov Pavel, Ponomarenko Ol’ga, MOROZOVA K. M.
Optimization and technical and economic evaluation of the process flow schemes of wastewater treatment of a plant for chicken egg advanced processing
Summary
The results of searching for the optimal process scheme for wastewater treatment of an enterprise for advanced processing of chicken eggs are presented. The optimization was carried out in terms of the life cycle cost (LCC) for a period of 25 years operation for the newly built treatment facilities with a capacity of 600 m3/day. The considered options include mechanical, one- and two-stage aerobic biological treatment in a membrane bioreactor with nitri-denitrification, with primary chemical pressure flotation with different doses of coagulant and without flotation. Process design was made on the basis of experimentally determined technological and kinetic parameters. The economic feasibility of primary physical and chemical purification was proved, and what is more, the most cost-effective was the treatment with Aqua-Aurat™-14 coagulant trademark with a dose of 125 mg/l as Al2O3, corresponding to the highest efficiency of physical and chemical purification. Retrofitting chemical flotation into the process flow scheme provided for reducing LCC by 7.7%. It is shown that with the availability of physical and chemical treatment dividing biological treatment into two stages virtually produces no economic effect on LCC. Taking into account the lowest energy consumption and the size of the structures the most useful option turned out to be the one with primary physical and chemical treatment and single-stage aeration tanks. The cost of wastewater treatment in this case was 99.66 RUB/m3, or 18.62 RUB/kg BODtot. For all the considered options in the LCC structure, the capital costs had the highest value – 22.2–27.9%, the payroll fund – 17.3–19.2%, equipment replacement – 17.4–19%.
Key words
wastewater , biological treatment , optimization , life cycle cost , physical and chemical treatment , egg processing enterprise , technical and economic evaluation , cost of wastewater treatment
|
DOI 10.35776/VST.2022.05.04
UDC 628.345
Stepanov S. V., Avdeenkov Pavel, Ponomarenko Ol’ga, MOROZOVA K. M.
The results of studies of physical and chemical wastewater treatment of an egg processing enterprise
Summary
The composition of wastewater of an enterprise for advanced processing of chicken eggs characterized by the following parameters: COD 3,600–12,200mg/l, concentration of suspended solids 1,206–3,031 mg/l, BODtotal 2,534–8,540 mg/l, no phosphates, pH 5.4– 13.2 was studied. The concentration of nitrogen compounds, mg/l, varied within the following ranges: ammonium – 0.4–11.4; nitrates – 0–15.3; nitrites – 0–7.3; organic nitrogen – 26.6–89.7. Based on the results of test coagulation, the optimal coagulant chosen was low-basic polyaluminum chloride brand «Aqua-AuratTM-14» with a dose of 125 mg/l as Al2O3. The average treatment efficiency while using this coagulant was, %: for COD – 77.3; for BODtotal – 76.3; for suspended solids – 80.1; for organic nitrogen – 58.7. The lowest concentration of residual aluminum 0.31 mg/l at the initial concentration of 0.29 mg/l corresponded to pH 6.7–7. Unit costs for the coagulant amounted to 9.37 rubles/m3.
Key words
wastewater , coagulation , aluminium polyoxychloride , food industry , physical and chemical treatment , egg processing enterprise
|
UDC 628.33:628.179.2
DOI 10.35776/VST.2023.01.05
Galkin Iurii, Baskov Evegenii, Ulasovets Evgenii, Obadin Dmitrii, Ermakov Denis, Knaub Elena
Technology for the treatment and use of mixed domestic and industrial wastewater in the industrial water supply system
Summary
According to the Terms of Reference of the ironworks, ECO-PROJECT R&D Company developed a physicochemical technology for the treatment of mixed domestic and industrial wastewater based on laboratory studies and pilot tests. The technology provides for reusing the effluent in the industrial water supply system of the ironworks, thus eliminating the discharge into the municipal domestic sewer network. With the help of mathematical modeling according to the methodology of ECO-PROJECT Company, an optimal scheme for using the obtained effluent in the industrial water supply system of the enterprise was developed. The feasibility study proved the environmental and economic efficiency of the implementation of this project.
Key words
disinfection , physical and chemical treatment , mixed domestic and industrial wastewater , industrial water supply system of an enterprise
|
|
