One of the key points for the large-scale implementation of electrochemical water treatment technologies lies in the need of reducing the energy consumption. The present work analyzes the removal of persistent perfluorohexanoic acid (PFHxA, 204 mg L⁻¹) from industrial process waters using a strategy that combines membrane pre-concentration followed by electrooxidation of the concentrate. A mathematical model describing the nanofiltration (NF) system was developed and complemented with new and background experimental data of PFHxA and ion species rejections and total permeate flux through the NF270 and NF90 membranes. Similarly, the kinetics of PFHxA electrolysis on boron doped diamond anodes was determined at laboratory scale. Later, the model was used to simulate the NF-ELOX integrated process, where a commercial spiral wound unit (membrane area 7.6 m²) was implemented and the electrooxidation unit was scaled-up to pilot plant (anode area 1.05 m²). The obtained energy savings depended on a combination of the target PFHxA removal ratio at the end of the treatment train, the separation performance of the commercial membrane and the reduction of the electrolyte ohmic resistance in the electrooxidation stage, that was attained as a result of the increase of salts content in the concentrate. Only the tight NF90 membrane allowed to achieve high (99%) PFHxA removal ratios in the integrated NF-ELOX process, and the specific energy consumption was estimated at 11.6 kWh m⁻³, 59.2% less than when electrolysis alone was applied. Still, the electrolysis is the most energy demanding step, with 85.9% contribution to the total energy consumption. The strategy of combining membrane pre-concentration with electrochemical degradation could be extended to the treatment of other highly persistent organic compounds.

大规模实施电化学水处理技术的关键点之一是需要降低能耗。本工作分析了持久性全氟己酸（PFHxA，204 mg L ^-1），该工艺采用结合了膜预浓缩和浓缩液的电氧化的策略。建立了描述纳滤（NF）系统的数学模型，并补充了新的和背景的PFHxA实验数据，离子物种截留率和通过NF270和NF90膜的总渗透通量。同样，在实验室规模下确定了在掺硼金刚石阳极上PFHxA电解的动力学。后来，该模型用于模拟NF-ELOX集成过程，其中实施了商用螺旋缠绕单元（膜面积7.6 m ²），电氧化单元按比例扩大至中试工厂（阳极面积1.05 m ^2））。所获得的能量节省取决于处理过程结束时的目标PFHxA去除率，市售膜的分离性能以及电氧化阶段中电解质欧姆电阻的降低等综合因素。增加精矿中的盐含量。在集成的NF-ELOX工艺中，只有紧密的NF90膜才能实现高（99％）的PFHxA去除率，比能耗估计为11.6 kWh m ^-3，比单独电解时减少了59.2％。电解仍然是最耗能的步骤，占总能耗的85.9％。将膜预浓缩与电化学降解相结合的策略可以扩展到其他高度持久性有机化合物的处理。