Research on the Application of Hollow Fiber Reverse Osmosis Membrane for High-power Concentration of High-salt Wastewater

A hollow fiber reverse osmosis(RO) membrane was used under low-pressure operating system to replace the energyintensive evaporation and concentration unit based on the phase transition process in the inherent process, realizing the high concentration of high-salt wastewater. It was found that using a multi-stage reverse osmosis process can reduce the osmotic pressure difference between the two sides of the membrane, and concentrate the concentrated brine with total dissolved solids(TDS) of 6% to 7% to more than 14% under 7 MPa inlet pressure, which can replace the evaporation and concentration unit or reduce the treatment scale of the evaporation unit, significantly reducing the investment and operating costs. Compared with the MVR process, the hollow fiber reverse osmosis membrane process can save operating costs about 398,600 yuan(RMB) per year, with which excess investment costs can be recovered after 15 months. The operating power consumption of the system using the multistage series process is only 58.6% of that of the evaporation and concentration technology. Considering all the costs together, it was found that the average operating cost of the process was reduced by around 25%. Therefore, this research is expected to provide a new efficient, simple and low energy consumption solution for the concentration and disposal of high saline wastewater.