Hybrid forward osmosis (FO) processes such as forward osmosis with membrane bioreactors (FO-MBR), electrodialysis (FO-ED), nanofiltration (FO-NF) or reverse osmosis (FO-RO) present promising technologies for wastewater reuse in agriculture as they meet high effluent quality requirements, especially regarding boron and/or salt content. An FO-NF demonstration plant for this application was built and operated treating 3 m³ h⁻¹ of real wastewater with a salinity of 3–5 mS cm⁻¹ and 1.5 mg L⁻¹ of boron in continuous mode for 480 days. Three draw solutions (DS) were evaluated in different periods of experimentation. Sodium polyacrylate led to reversible fouling on the FO and NF membranes and the permeate was not suitable for irrigation. Magnesium sulphate, used as DS in a second phase, generated severe irreversible fouling on NF membranes and therefore it was discarded. Finally, magnesium chloride showed the best performance, with FO-NF membranes presenting a stable permeability and low membrane fouling during long-term operation. The FO-NF permeate showed high quality for irrigation, achieving a conductivity value of 1 mS cm⁻¹, a boron concentration below 0.4 mg L⁻¹ and an average SAR of 1.98 (mequ L⁻¹)^0.5. DS replacement costs were reduced by working with high rejection NF membranes. However, energy consumption costs associated with the NF step make the global process more energy intensive than conventional technology.

混合正向渗透（FO）工艺，例如与膜生物反应器（FO-MBR）进行正向渗透，电渗析（FO-ED），纳滤（FO-NF）或反渗透（FO-RO），为农业废水回用提供了有希望的技术它们满足高废水质量要求，尤其是硼和/或盐含量方面的要求。建造并运行了一个用于该应用的FO-NF示范工厂，用于处理3 m ³  h ^-1的实际废水，其盐度为3–5 mS cm ^-1和1.5 mg L ^-1连续模式下连续480天注入硼。在不同的实验阶段评估了三种提取溶液（DS）。聚丙烯酸钠导致FO和NF膜上的可逆结垢，并且渗透液不适合灌溉。硫酸镁在第二阶段用作DS，在NF膜上产生了严重的不可逆结垢，因此将其丢弃。最后，氯化镁表现出最好的性能，而FO-NF膜在长期运行过程中表现出稳定的渗透性和低的膜污染。FO-NF渗透液显示出高品质的灌溉效果，电导率值为1 mS cm ^-1，硼浓度低于0.4 mg L ^-1，平均SAR为1.98（mequ L ^-1）^0.5。通过使用高截留率的NF膜，可以降低DS的更换成本。但是，与NF步骤相关的能耗成本使全局过程比传统技术更加耗能。