UC Riverside

This dissertation addresses key challenges in brine management from inland desalinationand the reuse of agricultural drainage water, both critical for sustainable water resource management in arid regions. While the first three studies focus on managing and treating brine from inland desalination, the fourth explores gypsum scaling mitigation in reverse osmosis (RO) desalination of agricultural drainage water, broadening the application of these findings. The first study investigates a 116-km brine pipeline in Southern California, where brine chemistry and solid precipitation lead to scaling, impacting pipeline efficiency. Results highlight the need for enhanced brine pretreatment and operational optimization to mitigate scaling. The second study introduces an ultraviolet-driven persulfate oxidation (UV/PS) method to degrade antiscalants, which facilitates efficient calcium removal through subsequent chemical demineralization, demonstrating an innovative approach to brine treatment. The third study extends this approach by combining UV/PS, chemical demineralization, microfiltration, and secondary RO, resulting in over 75% freshwater recovery in the secondary membrane desalination and significant mineral recovery, showcasing the potential for sustainable inland brine management. The fourth study shifts focus on the desalination of high-salinity agricultural drainage water, where gypsum scaling due to calcium and sulfate poses a severe challenge. This study evaluates the effectiveness of three antiscalants (DTPMP, NTMP, and PAA) under varied pH conditions to prevent gypsum scaling during RO. Findings reveal distinct mechanisms for each antiscalant, with DTPMP providing the most effective inhibition. These insights offer targeted strategies to improve RO efficiency and facilitate the reuse of agricultural drainage water. Collectively, this dissertation presents an integrated approach to inland brine management, resource recovery, and agricultural water reuse. The findings contribute practical, scalable solutions for enhancing water treatment infrastructure in water-scarce regions and offer foundational insights for future advancements in sustainable desalination processes.