Produced water from energy-related activities is one of the largest man-made wastewater streams. Membrane treatment of these waters offers the potential for reducing both total dissolved solids and specific ion concentrations; however, these highly impaired waters are subject to extensive fouling and poor separation. Among the plethora of constituents present in produced water, boron is of utmost concern due to toxicity and its potential to interfere with particular fracturing fluids during water reuse. Due to its uncharged nature at neutral pH, as well as its small size and hydration characteristics, removal of boron by conventional nanofiltration (NF) and reverse osmosis (RO) membranes can be challenging. Integrated membrane systems with pretreatment are often utilized to achieve multiple water quality objectives while minimizing fouling; electrodialysis (ED) is an attractive option for this application because it provides separation of both cationic and anionic constituents to prevent precipitation and subsequent membrane fouling (e.g., calcium carbonate). This study implements an integrated ED/NF system to assess the removal of boron in produced water and evaluate reductions in membrane fouling through ED pretreatment. Both selective adsorption and boron rejection are evaluated within this work. Advanced membrane materials have been synthesized and evaluated to provide a range of potential treatment options. A key focus of our current work has been on sorption of boron to membrane surfaces through diol modifications. Additional on-going work is aimed at enhancing boron rejection through rational tailoring of desired functionalities. These potential membrane improvements to promote repulsion include the incorporation of negatively-charged species within the polymer matrix and the tuning of selective-layer chemistries to alter membrane hydrophobicity.

Novel approach to boron removal in produced water by an integrated electrodialysis-nanofiltration system using selective membranes

2019 Fall National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.