Hybrid zero liquid discharge (ZLD) membrane/chemical process for the treatment of oil sands produced water

In this study, the applicability of a hybrid chemical/membrane process for the treatment of the boiler blow-down (BBD) water from steam assisted gravity drainage (SAGD) operation was explored. For the chemical pre-treatment prior to the membrane filtration, another waste stream of SAGD, i.e., ion exchanger regeneration wastewater (IERW), was used as a coagulant to reduce the concentration of organic matter and silica. The proposed method involved the direct use of the NF process for the purification of BBD water, followed by an integrated IERW conditioning and nanofiltration (NF) to purify the concentrated retentate. This process could operate with a zero-liquid discharge (ZLD) configuration and it was found to be an efficient method in terms of water recovery and water product quality.