Sorption and Membrane Technologies for Mine Water Purification

Abstract

The importance of the research is due to the lack of potable water (~1.6 million m3 per year) in a rapidly developing city in the Urals. One way to solve this problem is to purify water from the spent copper mine with a debit of ~4.4 million m3 of water per year. The most advanced techniques recently used for obtaining drinking water of a high quality are based on ion exchange and reverse osmosis, which can ensure an obtainment of water with initial contents of impurities much below the maximum permissible values. Based on the real experience the article compares sorption and membrane technologies in terms of water purification efficiency and cost of potable water production. The large-scale tests of mine water purification were carried out at sorption and reverse osmosis pilot plants with the capacity of 1 m3 per hour for the incoming flow. The source water had the following composition, mg/dm3: 0.5–0.9 Mn; 1.0–1.7 Ni; 80-140 Ca; 30-40 Na; 40-70 Mg; 0.2–0.6 Cu; 8.1–9.5 Si; 0.01–0.03 Zn; 0.01–1.70 Fe; <0.01 Al; < 0.005 As; < 0.005 Pb. At the same time the salinity was 640–680 mg/dm3, the water hardness was 9.5–11.5 mmol/dm3 and pH was 7.0-7.5. The content of non-mentioned impurities was below the detection limit. The resulting treated water met the requirements for the quality of potable water for both purification techniques. It was concluded, that the best option for treatment of mine water is ion exchange.