Electro-Driven Membrane Processes for Selective Ammonia Recovery from Wastewater
Nutrient is major component removed in wastewater treatment plants, including
ammonia that is typically converted into nitrogen gas through biological processes. If
recover properly, ammonia in wastewaters can potentially displace a significant
amount of s ynthetic fertilizer to enable a circular economy by improving resource
efficiency. Electro driven membrane processes provide a compelling means to
ammonia recovery through electrochemically driven separation and elevated solution
pH, coupled with membrane stripping. To enable practical implementations of this
ammonia recovery technology, three novel strategies to improve energy efficiency and
ammonium selectivity have been explored in this dissertation.
The first project has demonstrated the use of a proton mediated redox couple for ammonia recovery from municipal wastewater, which significantly reduced energy use
by lowering the cell potential needed for redox reactions relative to previous
approaches su ch as electrolysis of water. The second project aimed to improve the
selectivity towards ammonium ions by introducing a layer of nanocrystalline Prussian
blue analogues to the surface of a cation exchange membrane. The third project
explored the use of bip olar membranes in an electrodialysis cell. This work examined
how proton and hydroxide generated at the membrane interface influence ammonia
recovery in a membrane contactor, along with energy consumption to produce a
concentrated ammonium solution as a fi nal product at a larger scale.
Location: CAMP 372
Date : August 30 , 2023 Wednesday
Time: 10:00 AM
Advisor: Prof. Taeyoung Kim
Committee members:
Prof. Silvana Andreescu
Prof. Stefan Grimberg
Prof. Shane Rogers
Prof. Yang Yang