Capture of ambient air CO2 from municipal wastewater mineralization by using an ion-exchange membrane

The capture of ambient air CO2(gas) from synthetic urban wastewater mineralization reaction was studied. An ion exchange membrane was used as sorbent, which adsorbs CO2 when dry and releases it when wet. The UV/H2O2 degradation process was chosen to convert Total Organic Carbon (TOC) to carbon dioxide due to its advantages of convenience and fast kinetics over the conventional biological treatment that is usually used in urban wastewater treatment plants. In the first phase, experiments combining UV-C light and H2O2 were carried out to select the optimal values of the following parameters: pH, the dose of H2O2 and temperature. In the second stage, the CO2(gas) emission into the air from the degradation of organic compounds present in wastewater during UV/H2O2 process in the absence or presence of ion exchange membranes was evaluated. The effects of parameters such as temperature or air humid -ity were studied. A qualitative study of desorption was carried out to check the viability of reuse CO2 captured in the membrane. Finally, a similar CO2(gas) adsorption capacity after five cycles of adsorption and regeneration of the membranes was observed, being percentage loss of around 4%. (c) 2021 Elsevier B.V. All rights reserved.