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 BOD_tot. 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

Estimation of the technical and economic expediency of biological wastewater treatment facilities for oil extraction enterprises using a biocenosis of aerobic thermophilic microorganisms

Summary

A process flow scheme was developed for the biological treatment of wastewater of oil extraction production enterprises using aerobic thermophilic microorganisms immobilized on inert media. Based on the constants of the equations of enzymatic kinetics of biological wastewater treatment obtained during the experimental studies, a methodology for calculating the facilities was adapted, and formulas were substantiated to calculate the residence time in aeration facilities providing for a set treatment level. A technical and economic analysis showed the feasibility of using the proposed biological treatment method in bioreactors with a biocenosis of aerobic thermophilic microorganisms immobilized on a biological media block. Based on the calculation of the life cycle cost, the economic feasibility of the developed technology for the treatment of wastewater from oil extraction production was proven; the prime cost was 25.68 rubles/m3.

Key words

biological treatment , life cycle cost , technical and economic evaluation , cost of wastewater treatment , aerobic thermophilic microorganisms , oil extraction production