UCLA

Water stress, resource scarcity, and the interdependency of food, water, and energy sectors highlight the need for developing and improving efficient resource and water management practices. While current wastewater management practices treat large volumes of wastewater and can remove nutrients that would otherwise be released into and pollute the environment, they do not meet the current needs to close the nutrient cycle and effectively recover nutrients present in wastewater. Currently, biological removal and chemical precipitation are the two most common methods employed for nutrient recovery, however, these processes are highly susceptible to feed compositions, temperature, and diurnal variations, and recover nutrients such as nitrogen or phosphorus, as nitrogen gas or struvite, a slow-release fertilizer of low commercial value. To this end, membrane-based wastewatertreatment processes have emerged as an efficient alternative to remove and recover these nutrients. In this work, we develop two novel membrane-based treatment technologies to effectively recover nutrients in their usable form as NH4+ and PO43-. We first developed an electrically conducting membrane to facilitate interfacial reactions at the membrane surface and recover ammonia from wastewater, while in the second project, we developed a novel ion exchange membrane capable of selectively transporting phosphate ion over other common ions by leveraging intermolecular interactions between the ion and membrane. The results demonstrate that ammonia was effectively recovered using our novel membrane and setup. Moreover, the process developed here reduced the overall energy consumption by 50% compared to traditional processes. The results also show that the ion exchange membrane is capable of highly efficient phosphate ion separation with a selectivity of up to a 100 compared to other competitive ions in solution.