Reagent treatment of bild water in ship separators

В работе представлены результаты экспериментальных исследований флотационной очистки судовых льяльных вод. Установлена целесообразность предварительной реагентной обработки судовых льяльных вод, направляемых на флотационную очистку. В качестве реагентов апробированы высокомолекулярные флокулянты: Праестол 852, Праестол 853 и К 1020. Определен наиболее эффективный флокулянт – Праестол 852. Обоснована целесообразность применения во флотационных машинах судовых сепараторов диспергаторов воздуха, выполненных из синтетического каучука. Использование синтетического каучука позволяет повысить эффективность извлечения нефтяных загрязнений, а также обеспечить бесперебойность и долговечность работы установки. Методом анализа размерностей получено критериальное уравнение процесса флотации нефтяных загрязнений из раствора льяльных вод. Исследовано влияние следующих технологических параметров процесса: интенсивности подачи воздуха, высоты слоя обрабатываемой жидкости, физико-химических характеристик жидкости, расхода воздуха и льяльной воды. Разработана математическая модель процесса флотации. Определены оптимальные параметры процесса. The paper presents the results of experimental studies of flotation treatment of ship bilge waters. The expediency of preliminary reagent treatment of ship bilge water sent for flotation treatment has been established. High molecular weight flocculants were tested as reagents: Praestol 852, Praestol 853. K 1020. The most effective flocculant, Praestol 852, has been determined. The expediency of using in flotation machines of ship separators of air dispersers made of synthetic rubber has been substantiated. The use of synthetic rubber makes it possible to increase the efficiency of the extraction of oil contaminants, as well as to ensure the uninterrupted and durable operation of the installation. The criterion equation of the process of flotation of oil pollution from a bilge water solution was obtained by the method of dimensional analysis. The influence of the following technological parameters of the process was investigated: the intensity of the air supply, the height of the treated liquid layer, the physicochemical characteristics of the liquid, the air and bilge water consumption. A mathematical model of the flotation process has been developed. The optimal parameters of the process have been determined.

FLOTATION IN TECHNOLOGICAL SCHEMES OF INDUSTRIAL WASTEWATER TREATMENT

The necessity of measures to prevent environmental pollution by industrial emissions, in particular sewage, is substantiated. It has been shown that one of the most promising methods for cleaning industrial wastewater is flotation. Its essence, characteristics and types of flotation are discussed. The factors that determine the use of different types of flotation for the treatment of industrial wastewater are listed. It is shown that the flotation method can be used to concentrate various in nature pollutants from industrial wastes: suspended solids, petroleum products, fats, heavy metal ions, surfactants. It has been established that pressure flotation, electroflotation and ion flotation are most widely used in the practice of cleaning industrial wastewaters. Their advantages compared with other types of flotation are considered. The reasons constraining the widespread use of flotation methods for the treatment of industrial wastewater are discussed. Examples of effective technological schemes for wastewater treatment of a number of industries (oil refineries, meat industry, hydrometallurgical industry, electroplating industry), including the stage of flotation treatment of wastewater are given. The factors that determine the use of flotation treatment of wastewater in technological schemes at a certain stage of industrial effluent treatment are determined. The conclusion was made about the universality of the flotation method, which allows to effectively remove a wide range of contaminants from industrial wastewater, and also successfully combine with widely known purification methods in technological schemes as a preliminary, basic method of purification or additional treatment of effluent up to regulatory requirements.

The Use of Polymers in the Flotation Treatment of Wastewater

The use of flotation for the treatment of wastewaters in general, but especially for the removal of oil, grease, general organic matter, and suspended solids, is well established as a low energy process. Polyelectrolytes (PEs) can enhance performance without adding to the solids load that occurs with inorganic additives such as alum. The bridging of pollutants and the attachment of the resulting aggregates to the air-water interface can be effectively carried out with most wastewaters. Hydrophobic modification of the PEs can be useful for difficult species. It should be applied to the flotation of polyfluoroalkyl substances, for example, as they are not amenable to economical conventional treatment. Similarly, the removal of microplastic particles from sewage effluents by flotation could be enhanced.

UNBURNT CARBON REMOVED FROM FLY ASH BY FLOTATION METHOD

Because fly ash has pozzolanic activity, it has been used for a long time as an admixture for concrete. However, unburnt carbon in the fly ash adversely affects the fresh properties of concrete. For this reason, when fly ash having a high unburnt carbon content is used as an admixture for concrete, it is desired to reduce the amount of unburnt carbon. So far, at our university, we have developed a technique to remove unburnt carbon by flotation method. It is necessary to add a scavenger and a foaming agent when using this equipment. However, the appropriate amount is unknown. Therefore, we investigated a method to easily estimate the amount of chemicals suitable for flotation treatment from the physical properties of raw fly ash. It is obvious that efficient treatment can be performed when the addition amount of scavenger and the addition amount of foaming agent is set to 10: 1, and that the addition amount of the agent can be accurately estimated by using the methylene blue adsorption amount of fly ash.

STRUCTURAL MODELING OF SEWAGE WATER AERATION PROCESS IN A SURFACE TYPE SATURATOR AS AN OBJECT OF AUTOMATION

As part of solving the problem of finding technical approaches that contribute to the achievement of environmental protection goals, special attention is paid to sewage treatment facilities, which are the main sources of hydrosphere pollution. The treatment of liquid wastes of enterprises is a complex chain of technological redistributions, each of which is characterized by a multitude of parameters. There has been considered the process of saturation with air in a surface type saturator, which is important in terms of the quality of flotation treatment of wastewater. To create effective systems for automatic control of the technological stage under investigation it is proposed to apply an approach, one element of which is to find mathematical description of the object in the form of equations and structures. It is shown that aeration of effluents is a multidimensional non-stationary object of control, whose output coordinates are the liquid level and air pressure in the pressure tank and the air concentration in the drain at its outlet. Vectors of control and disturbing influences are singled out. The first vector includes the level of fluid and air pressure in the reservoir, the concentration of air in the outlet solution, the second one includes the temperature of water and air at the inlet to the plant and the flow of outgoing liquid, temperature and the speed of the air outside. Mathematical description of the process of air saturation of sewage water in a surface type saturator as an automation object is given. On the basis of the resulting system of equations, a structural diagram of the mathematical model is synthesized, which can later be used to create computational models of the object and the control system of the sewage treatment complex.