Combined Microfiltration and Reverse Osmosis Process for Mine Water Treatment
When mining minerals such as coal, there is a need for constant diversion of large volumes of mine water from mine workings, to prevent flooding of the underground horizons. Taking into account the scarcity of water resources in the Donetsk region, mine water can be considered as a real alternative source of water supply. Pollution prevention of ground and underground water sources and direct involvement of purified water resources in the economic turnover of the enterprise can be achieved as a result of mine water treatment by a combined process of microfiltration and reverse osmosis. In the course of the study it was necessary to understand how effective the membrane method of water purification is. The analysis to study the concentration of pollution was carried out in laboratory conditions, for which mine water samples were taken and prepared in advance. The analysis was carried out before the start of treatment (source water), as well as after each stage of treatment. For cleaning, the technology of the selected membrane process consisting of two stages was used: 1) microfiltration - this system is equipped with a ceramic membrane that is resistant to mechanical stress, pressure surges, heating to 150 °C, and also the pH range of which is from 0,5 to 13,5, which in turn allows to clean the membrane with aggressive chemicals; 2) reverse osmosis - this system also has a ceramic membrane that allows the process of water primary purification, the temperature regime in this system ranges from 2 to 40 °C, and the pressure range, in turn, from 300 to 400 kPa. In the process of purification after demineralization of the source water in the system, a reverse stage is connected after reverse osmosis, the water in which is enriched with minerals. Here, the Semidol mineralizer is already used. Semidol is a dolomite filter material used to purify water of various types of pollution. It consists of pure dolomite and also has an ideal stoichiometric composition. Semidol is used as a filter material due to the fact that the content of inorganic substances is significantly lower than the acceptable purity requirements. In the course of the study the technology of the combined process of water purification has shown that there is not only an environmental, but also an economic effect. It allows to reduce significantly the cost of water consumption and water diversion both at industrial enterprises and for urban water consumption.