Key Laboratory of Drinking Water Science and Technology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
Key Laboratory of Drinking Water Science and Technology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of forestry, Northeast Forestry University, Harbin 150040, China.
Sci Total Environ. 2021 Jun 25;775:145617. doi: 10.1016/j.scitotenv.2021.145617. Epub 2021 Feb 4.
The alkali-innocuous citric acid (CA) modified wood membranes (WMs) have been developed as facile, economical, and effective adsorption membranes to remove tetracycline (TC) from water. However, TC removal by modified WMs with different types of wood channel walls have rarely been compared. Therefore, in this study, modified WMs were prepared with pinewood (PW) and basswood (BW). The PW and BW WMs before and after modification were characterized by SEM, EDX, XRD, ATR-FTIR, TGA, contact angle and zeta potential. After modification, cellulose I in cellulose crystal structures of raw WM transformed to cellulose II and the contents of carboxylic groups for PW and BW were enhanced to make the hydrophilicity of WM surface increased. Compared with modified PW WMs, particles formed on the channel walls of modified BW WMs containing vessel pits to make more carboxylic groups introduced. The TC adsorption breakthrough curves showed that the 6 wt% alkali- CA modified BW had an effective filtration volume of 1968 bed volume (BV) compared with the 4 wt% alkali-CA modified PW of 1205 BV as the influent TC and breakthrough point were chosen at 2 and 0.5 mg/L, respectively. At low pH, TC complex with WM surfaces through Lewis acid-base interaction. Zwitterionic TC was shown to favor adsorption onto WM via hydrogen bonding at pH of around 5. With further increasing pH, TC adsorption efficiency decreased due to the electrostatic repulsion. The costs of modified BW and PW are about 0.0054-0.0126 US$/m and 0.01-0.024 US$/m for a low TC concentration effluent (0-0.5 mg/L), respectively. This work shed a new sight on how to develop economical and effective adsorption WMs for contaminants removal from water.
碱无害柠檬酸（CA）改性木膜（WM）已被开发为简便、经济且有效的吸附膜，可从水中去除四环素（TC）。然而，具有不同类型木材通道壁的改性 WM 去除 TC 的效果很少被比较。因此，在这项研究中，使用松木（PW）和椴木（BW）制备了改性 WM。通过 SEM、EDX、XRD、ATR-FTIR、TGA、接触角和zeta 电位对改性前后的 PW 和 BW WM 进行了表征。改性后，纤维素晶体结构中原 WM 的纤维素 I 转化为纤维素 II，且 PW 和 BW 的羧酸基团含量增加，使 WM 表面的亲水性增加。与改性 PW WM 相比，含有导管腔的改性 BW WM 通道壁上形成了颗粒，从而引入了更多的羧酸基团。TC 吸附突破曲线表明，与进水 TC 选择为 2 和 0.5 mg/L 时分别为 1205 BV 和 4 wt%碱-CA 改性 PW 相比，6 wt%碱-CA 改性 BW 的有效过滤体积为 1968 BV。在低 pH 下，TC 通过路易斯酸碱相互作用与 WM 表面络合。两性 TC 显示出在 pH 约为 5 时通过氢键有利于吸附到 WM 上。随着 pH 的进一步增加，由于静电排斥，TC 的吸附效率降低。改性 BW 和 PW 的成本分别约为 0.0054-0.0126 美元/m 和 0.01-0.024 美元/m，用于处理低 TC 浓度（0-0.5 mg/L）的出水。这项工作为开发用于从水中去除污染物的经济有效的吸附 WM 提供了新的思路。
