Boron removal from synthetic hydraulic fracturing wastewaters by hybrid nanofiltration/complexation process

The primary purpose of this study is to investigate boron removal from synthetic hydraulic fracturing wastewater by membrane processes. The effects of pressure, pH, feed concentration, and polyol concentration on boron removal were determined using a cross-flow, flat-sheet membrane test unit. The nanofiltration membrane was tested within the scope of the experiments. Accordingly, it was determined that the boron removal increased with pressure, pH, and boron concentration. Under the influence of all these variables, the complexing polyol was used in the membrane experiments to remove the boron at a higher level. Xylitol, one of the polyols that forms the most efficient complex with boric acid, was added to the synthetic hydraulic fracturing wastewater at specific molar ratios. In NF membrane tests with polyol addition, >80% boron removal was recorded under specific operating conditions. High-quality permeate water obtained after membrane treatment can be reused as a hydraulic fracturing fluid. It has been proven that the proposed treatment setup can be an effective alternative for boron removal from hydraulic fracturing wastewater.