Cross-stacked super-aligned carbon nanotube/activated carbon composite electrodes for efficient water purification via capacitive deionization enhanced ultrafiltration |
| |
Authors: | Min Li Shuai Liang Yang Wu Meiyue Yang Xia Huang |
| |
Institution: | 1. Beijing Key Laboratory for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China2. Department of Mechanical Engineering and Tsinghua Foxconn Nanotechnology Research Center, Tsinghua University, Beijing 100084, China3. State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China |
| |
Abstract: | ? A high-performance electrode was prepared with super-aligned carbon nanotubes. ? SACNT/AC electrode achieved a ~100% increase in desalination capacity and rate. ? SACNT/AC electrode achieved a ~26% increase in charge efficiency. ? CUF process with SACNT/AC achieved an up to 2.43-fold fouling reduction. ? SACNT/AC imparts overall improved water purification efficiency. The practical application of the capacitive deionization (CDI) enhanced ultrafiltration (CUF) technology is hampered due to low performance of electrodes. The current study demonstrated a novel super-aligned carbon nanotube (SACNT)/activated carbon (AC) composite electrode, which was prepared through coating AC on a cross-stacked SACNT film. The desalination capability and water purification performance of the prepared electrode were systematically investigated at different applied voltages (0.8–1.2 V) with a CDI system and a CUF system, respectively. In the CDI tests, as compared with the control AC electrode, the SACNT/AC electrode achieved an approximately 100% increase in both maximum salt adsorption capacity and average salt adsorption rate under all the applied voltage conditions, demonstrating a superior desalination capability. Meanwhile, a conspicuous increase by an average of ~26% in charge efficiency was also achieved at all the voltages. In the CUF tests, as compared with the control run at 0 V, the treatment runs at 0.8, 1.0, and 1.2 V achieved a 2.40-fold, 2.08-fold, and 2.43-fold reduction in membrane fouling (calculated according to the final transmembrane pressure (TMP) data at the end of every purification stage), respectively. The average TMP increasing rates at 0.8, 1.0, and 1.2 V were also roughly two times smaller than that at 0 V, indicating a dramatical reduction of membrane fouling. The SACNT/AC electrode also maintained its superior desalination capability in the CUF process, resulting in an overall improved water purification efficiency. |
| |
Keywords: | Carbon nanotube Super aligned Conductive membrane Capacitive deionization Ultrafiltration Desalination |
|
| 点击此处可从《Frontiers of Environmental Science & Engineering》浏览原始摘要信息 |
| 点击此处可从《Frontiers of Environmental Science & Engineering》下载免费的PDF全文 |
|