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

The capture of ambient air CO from synthetic urban wastewater mineralization reaction was studied. An ion exchange membrane was used as sorbent, which adsorbs CO when dry and releases it when wet. The UV/HO 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 HO were carried out to select the optimal values of the following parameters: pH, the dose of HO and temperature. In the second stage, the CO emission into the air from the degradation of organic compounds present in wastewater during UV/HO process in the absence or presence of ion exchange membranes was evaluated. The effects of parameters such as temperature or air humidity were studied. A qualitative study of desorption was carried out to check the viability of reuse CO captured in the membrane. Finally, a similar CO adsorption capacity after five cycles of adsorption and regeneration of the membranes was observed, being percentage loss of around 4%.