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