The global water crisis continues to be a major challenge due to rapidly increasing water demand and deteriorating water quality due to pollution. Treated wastewater is a renewable and unconventional water resource that, if treated efficiently, could increase water supplies. However, conventional wastewater treatment systems are proving inadequate in removing bioaccumulative, persistent, and toxic contaminants that have recently been discovered in treated wastewater. To overcome these limitations, our research focuses on harnessing the potential of porous materials to revolutionize water treatment. The advent of reticular materials, namely metal-organic frameworks (MOFs) and covalent-organic frameworks (COFs), has led to remarkable advances in structural control and tuning of chemical functions. These breakthroughs have led to new classes of highly efficient membranes and adsorbents for water treatment.
Our work in water treatment exploits the molecular design capabilities of the porous structure and functionality of COFs for the removal of contaminants from water. Our research demonstrates control of the surface wettability and porous structure of stand-alone COF membranes to produce superhydrophilic membranes for removal of oil from oil-in-water suspensions. These membranes exhibit excellent oil rejection of up to 99% and high water flux of over 3500 L/m²h. In addition, our studies show the significant efficacy of molecularly-designed COF-based adsorbents in removing persistent contaminants of emerging concern, such as perfluorooctanoic acid (PFOA). These adsorbents have a superior adsorption capacity of 2500 mg/g within a few seconds, making them highly suitable for household water filters.
By using molecular-level design tools, we aim to produce highly efficient membranes and adsorbents with tailored nanochannels to increase the efficiency of wastewater treatment systems and combat the emergence of new classes of water contaminants. Our research holds promise for revolutionizing water purification processes, ensuring access to clean water, and addressing the urgent challenges of the global water crisis.
Keywords: porous materials, reticular materials, covalent-organic frameworks, water treatment, wastewater, contaminants, membranes, adsorbents, molecular design, oil removal, emerging contaminants, nanochannels, water purification.