(725e) Evaluation of Integrated Electrocoagulation-Microfiltration and Direct Contact Membrane Distillation Processes for Produced Water Treatment

Treating the wastewater generated from hydraulic fracturing operations is challenging because of the present of high salinity (total dissolved solids (TDS)), toxic organic & inorganic compounds, oil & grease, and naturally occurring radioactive materials. Membrane distillation (MD) is an emerging technology of interest for the treatment of high salinity brines. In this study, microfiltration (MF) was used to remove the flocs formed during the electrocoagulation (EC) pretreatment, and the MF permeate was treated further by direct contact membrane distillation (DCMD). Different types of membranes were investigated for the DCMD. In this work, we aimed to demonstrate the feasibility of an integrated EC-MF-DCMD system for water recovery from high salinity produced waters obtained from shale gas extraction facilities. During EC, a high removal efficiency of total organic carbon (48.4%) was obtained by using 6 aluminum plates with bipolar configuration at 9.5 A for 20 min. Keeping the feed tank temperature at 40 ^oC, while the temperature inside the model at 60 ^oC can effectively suppress crystallization on the membrane surface, which can significantly decrease scaling. 50% water recovery was obtained using commercial membrane over two DCMD cycles. However, organic fouling was still a big problem, especially surfactants due to forming micelles and bilayers, which can significantly decrease the flux and eventually block the membrane.