Activated sludge process is the biotic conversion of organic matter of wastewater to CO2 and biomass. The biological conversion of organic compounds in activated sludge relies on the efficient transfer of dissolved oxygen. Oxygen mass transfer from the gas phase to the liquid phase and microbial oxygen consumption are critical for effectively removing...

Background Per- and poly-fluoroalkyl substances (PFAS) are a wide group of organic compounds that have been extensively used in several applications due to their unique properties, including thermal stability, chemical stability, surfactant applications, and hydrophobicity. However, PFAS have been found to have detrimental effects on environment and...

Background Photoelectrocatalytic processes (PECs) combine photocatalysis and electrochemical principles to enhance charge carrier generation and stability within nanomaterials (NMs). Nano-enabled PECs can be used for water purification or hydrogen production applications. Current PEC designs face challenges due to low energy efficiencies, because most...

Background Electrochemical sensing is a compact process used to detect chemicals in aqueous solutions (e.g., water, bodily fluids, foods). It can also be used to treat pollutants in drinking and industrial wastewaters. Electrochemical oxidation can generate hydroxyl radicals, which are effective in degrading organic contaminants in water, including...

Background Adsorption is the main water treatment technology that is commercially used to remove per- and polyfluoroalkyl substances (PFAS) from water. These substances are in thousands of everyday products due to their high stability and chemical resistance, but are non-biodegradable and can pose risks to human health. Current adsorption techniques...

Background Ammonia (NH3) is a valuable compound for industrial, agricultural, and water treatment applications. The typical method for large-scale production of ammonia is the Haber-Bosch (HB) process, which uses hydrogen and nitrogen as reagents under high pressure and temperature. However, this process generates over 450 million tons of CO2 annually,...

Background Electrochemical sensors offer many advantages over traditional analytical instruments and are widely used in biomedical, environmental, and industrial applications. Mechanically flexible electrodes in electrochemical sensors are designed to be conformable to the surface they are placed on, and ensure better contact and adaptability to challenging...

Background Electrocatalytic nitrogen fixation could enhance the sustainability of global ammonia production. However, overcoming the high energy barrier to break the triple bond of dinitrogen (N2) has proved to be a challenge. Electrochemical reduction of nitrate (ERN) is an alternative solution, but ERN currently relies on platinum group metals (PGMs)...

­Bacteria, viruses, and other harmful microorganisms pose a significant pathogenic health-related risk to safe drinking water. Disinfection by chlorination is commonly practiced, however, chlorine is a toxic chemical that typically requires careful storage and proper handling. While ultraviolet (UV) disinfection can be effective, UV-based processes...

Background Reducing nitrate from water streams is an untapped source of nitrogen that could be used for decentralized ammonia production at ambient conditions for agricultural use with a significantly lower cost. Decentralized production of ammonia in rural areas can minimize environmental impacts of the Haber-Bosch process (including produced ammonia...