SYSTEM ANALYSIS IN BIOTECHNOLOGIES OF FOOD INDUSTRY ENTERPRISES WASTEWATER TREATMENT

Abstract

The food industry is characterized by the use of a large amount of water per unit of production, the formation of highly concentrated wastewater that does not contain toxic impurities, however, often has pH values that go beyond the recommended range of 6,5–8,5, may have significant concentrations of fats and require adjustment of the content of biogenic elements. Given the potential ability to biologically decompose organic pollutants and technological, economic and environmental advantages, aerobic biotechnologies for their purification play a central role in preventing water pollution by food industry wastewater. For preliminary and deep treatment of wastewater at food industry enterprises, a huge number of complex technologies are used, which, in addition to biological, involve the use of methods of mechanical and physico-chemical treatment, secondary treatment, disinfection and sludge treatment. Therefore, for the correct choice of wastewater treatment technology for a particular food industry enterprise, it is advisable to apply a system analysis of complex wastewater treatment biotechnologies. Structural analysis of the food industry enterprises wastewater treatment system of in the general case shows the following sequential functional elements, which are  subsystems of this system: 1) preliminary wastewater treatment; 2) biotechnological treatment of wastewater; 3)  secondary wastewater treatment (in the case of their discharge into an open water body); 4) disinfection; 4) sludge neutralization. Each element of the system determines the efficiency of the operation of the following elements of the technological scheme. Analysis and comparison of bioreactors of different types and designs showed that in terms of oxidation capacity, biomass concentration, biological treatment efficiency and energy efficiency, area occupied, ease of operation, number of service personnel, cost and duration of construction, the optimal ones for biological treatment of wastewater from food industry enterprises are aerotanks-settlers of increased hydraulic height with surface jet aeration of the NUWM design. Using the example of wastewater from meat processing enterprises, the dependence of the efficiency of biological treatment and sludge index on the load on activated sludge was studied. For mathematical modeling of the process of biological treatment of wastewater in production conditions, the Eckenfelder model was used. The amount of ammonium nitrogen nitrified in aerotanks-settlers and subsequently removed from wastewater by simultaneous denitrification was on average 0.2 kg/(m3·day).