Зниження рівня забруднень дріжджовмісних стічних вод в умовах кавітації

Abstract

Проведено аналіз сучасного стану та проблем техногенного забруднення навколишнього середовища стічними водами, що містять дріжджі. Запропоновано основи технології кавітаційного знезараження стічних вод з метою зменшення викидів в навколишнє середовище. Визначено константи швидкості дезагрегації дріжджових клітин та швидкості руйнування клітин мікроорганізмів у даній системі. Запропоновано технологічну схему процесу кавітації очищення стічних вод з використанням вібраційного електромагнітного кавітатора. Виконано техніко-економічне обґрунтування і оцінено еколого-економічну ефективність від впровадження технології віброкавітаційного очищення виробничих стоків підприємств харчової промисловості. Проведен анализ современного состояния и проблем техногенного загрязнения окружающей среды сточными водами, содержащие дрожжи и предложены основы технологии кавитационного обеззараживания сточных вод с целью уменьшения выбросов в окружающую среду. Определены константы скорости дезагрегации дрожжевых клеток и скорости разрушения клеток микроорганизмов в данной системе. Предложена технологическая схема процесса кавитационной очистки сточных вод с использованием вибрационного электромагнитного кавитатора. Выполнено технико-экономическое обоснование и рассчитана эколого-экономическая эффективность от внедрения технологии виброкавитационной очистки производственных стоков предприятий пищевой промышленности. The current state and problems of technogenic pollution of the environment by waste waters containing yeast has been analyzed. Fundamentals of cavitation technology have been proposed to disinfect wastewaters with the purpose to reduce discharges into the environment. It has been experimentally proved that at the first stage of processing the dispersion of microorganisms under cavitation conditions, disaggregation of cell colonies and growing number of individual cells per unit volume of the mixture is observed, which can be described by the equation of the first order. At the second stage of the treatment, destruction of cells takes place, which is described by the equation of the first order, with the release of organic substances, whose concentration grows with the degree of the destruction of cells in the system. Constants of disaggregation and destruction rates of cells of microorganisms in the system have been determined. It has been shown that cavitation increases the rate of inactivation and oxidation by15-40% depending on the conditions of the process behavior, and here a synergistic effect of cavitation and gas action is observed. The concentration of microorganisms in time for ultrasound treatment is changed according to the equation of the first order, and the process rate constant grows during the aeration of the suspensions with oxygen in the presence of hydrogen peroxide. The process of oxidation of organic substances in the acoustic field takes place as a reaction of the of the first order, and the process of oxidation of organic compounds that are released during the destruction of microorganisms is described by the equation of the second order, which is due to the heterogeneity of the system. It has been experimentally found out that glucose, as one of the products of yeast destruction, inhibits radical-chain oxidation of organic compounds that are released during the destruction of microorganisms; effective constants of inhibition of the process have been established. Maximal oxidation efficiency is achieved during 1-1.5 hours of the ultrasound treatment of the system that contains water-soluble organic compounds and microorganisms. At the same time, cells of microorganisms are practically completely destroyed, and organic compounds, resistant to oxidation, remain in the environment. The kinetic patterns and peculiarities of the US effect on model mixes (reaction orders, synergistic effect) are observed in industrial wastewaters containing yeast. The effect of the cavitation treatment during wastewater treatment with various concentrations of biological pollution at different vibration frequencies of soundboard disturbers of cavitation has been studied. The greatest effect has been achieved at the frequency of 37Hz, which increases the environmental safety of the enterprise. It has been found out that the effectiveness of the vibrating cavitation devices is higher than of ultrasound generators at lower power consumption. Chemical and biological effects during the application of vibration cavitation are similar to US. After the cavitation treatment of contaminated waters, a post-cavitation effect is observed, which lies in the reduction of the number of microorganisms per unit volume and COD. The microbial growth in the treated water starts only in 24 hours, whereas in the event of the photochemical decontamination, the microbial growth was observed already in 2 hours. A flow chart of the cavitation process of wastewater treatment with the use of an electromagnetic vibration cavitator is proposed. A feasibility study has been performed and environmental and economic efficiency of the introduction of the technology of the vibration cavitation treatment of industrial wastewaters of food industry enterprises has been assessed.