FO-RO for mining wastewater treatment

In this chapter, a combined forward osmosis (FO) and reverse osmosis (RO) process for mining wastewater treatment is discussed. Water interactions in mining process, wastewater characteristic treatment methods adopted, and the research technology gaps are briefly discussed. A lab-scale integrated FO-RO was developed to establish the proof of concept in applying this technology for mine water treatment. The integrated system has been tested under extended operation with various mine waters. The FO combined with RO could minimize the number of pretreatment steps required for the RO. Our results indicate that this technology can reduce the brine volume by at least 80% and recover a consistent quality reusable water. A pilot scale FO-RO with a capacity of 1 m3/day was designed and built, incorporating two different types of FO membranes. The study showed that this process can potentially offer a significant reduction in energy use, chemical use, piping infrastructure, and operating costs in desalinating mine water and the success of this technology is in the efficient process configuration and FO membrane module configuration, membrane chemistry and structure.