Study on bubble column humidification and dehumidification system for coal mine wastewater treatment

Water is important resource for human survival and development. Coal mine wastewater (CMW) is byproducts in the process of coal mining, which is about 7.0 × 10 10 m 3 in China in 2016. Considering coal mine wastewater including different ingredients, a new bubble column humidification and dehumidification system is proposed for CMW treatment. The system is mainly composed of a bubble column humidification and dehumidification unit, solar collector, fan and water tank, in which air is used as a circulating medium. The system can avoid water treatment component blocking for RO (reverse osmosis) and MED (multi effect distillation) dealing with CMW, and produce water greenly. By analysis of heat and mass transfer, the effects of solar radiation, air bubble velocity and mine water temperature on water treatment production characteristic are studied. Compared with other methods, thermal energy consumption (TEC) of bubble column humidification and dehumidification (BCHD) is moderate, which is about 700 kJ/kg (powered by solar energy). The results would provide a new method for CMW treatment and insights into the efficient coal wastewater treatment, besides it helps to identify the parameters for the technology development in mine water treatment.