| Autor: |
Lazarte JPL; Chemical Engineering Department, Malayan Colleges Laguna, Pulo-Diezmo Rd. Cabuyao City, Laguna 4025, Philippines. john_paolo_lazarte@dlsu.edu.ph.; Chemical Engineering Department, De La Salle University, 2401 Taft Avenue, Manila 1004, Philippines. john_paolo_lazarte@dlsu.edu.ph., Bautista-Patacsil L; Chemical Engineering Department, Malayan Colleges Laguna, Pulo-Diezmo Rd. Cabuyao City, Laguna 4025, Philippines. lbpatacsil@mcl.edu.ph., Eusebio RCP; Chemical Engineering Department, University of the Philippines Los Baños, College, Laguna 4031, Philippines. rpeusebio@up.edu.ph., Orbecido AH; Chemical Engineering Department, De La Salle University, 2401 Taft Avenue, Manila 1004, Philippines. aileen.orbecido@dlsu.edu.ph., Doong RA; Institute of Environmental Engineering, National Chiao Tung University, Hsinchu 30010, Taiwan. radoong@mx.nthu.edu.tw.; Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Sec. 2 Kuang-Fu Road, Hsinchu 30013, Taiwan. radoong@mx.nthu.edu.tw. |
| Abstrakt: |
The capability of novel 3:1 reduced graphene oxide/titanium dioxide nanotubes (rGO/TiONTs) composite to desalinate using capacitive deionization (CDI) employing highly concentrated NaCl solutions was tested in this study. Parameters such as material wettability, electrosorption capacity, charge efficiency, energy consumption, and charge-discharge retention were tested at different NaCl initial concentrations-100 ppm, 2000 ppm, 15,000 ppm, and 30,000 ppm. The rGO/TiONTs composite showed good material wettability before and after CDI runs with its contact angles equal to 52.11° and 56.07°, respectively. Its two-hour electrosorption capacity during CDI at 30,000 ppm NaCl influent increased 1.34-fold compared to 100 ppm initial NaCl influent with energy consumption constant at 1.11 kWh per kg with NaCl removed. However, the percentage discharge (concentration-independent) at zero-voltage ranged from 4.9-7.27% only after 30 min of desorption. Repeated charge/discharge at different amperes showed that the slowest charging rate of 0.1 A·g -1 had the highest charging time retention at 60% after 100 cycles. Increased concentration likewise increases charging time retention. With this consistent performance of a CDI system utilizing rGO/TiONTs composite, even at 30,000 ppm and 100 cycles, it can be a sustainable alternative desalination technology, especially if a low charging current with reverse voltage discharge is set for a longer operation. |
