Lin Jiuyang,Yu Zijian,Chen Tianci,Huang Junming,Chen Lianxin,Li Jiangjing,Li Xuewei,Huang Xiaolei,Luo Jianquan,Ang Elisa Yun Mei,Toh William,Wang Peng Cheng,Ng Teng Yong,Seo Dong Han,Zhao Shuaifei,Zhong Kuo,Xie Ming,Ye Wenyuan,Van der Bruggen Bart,Wan Yinhua
During the synthesis of dyes, desalination of high-salinity dye-containing waste liquor is a critical premise for high-quality, clean dye production. Conventional membrane processes, such as electrodialysis, nanofiltration and ultrafiltration, are inevitably subjected to serious membrane fouling, deteriorating the dye/salt fractionation efficacy. Integrating the technical merits of electrodialysis and pressure-driven membrane separation, we devise an electro-driven filtration process using a tight ultrafiltration membrane as alternative to conventional anion exchange membrane for rapid anion transfer, in view of dye desalination and purification. By employing a sub-4 nanometer tight ultrafiltration membrane as anion conducting membrane, the electro-driven filtration process achieves 98.15% desalination efficiency and 99.66% dye recovery for one-step fractionation of reactive dye and NaCl salt, markedly outperforming the system using commercial anion exchange membranes. Notably, the electro-driven filtration system displays a consistently high and stable fractionation performance for dyes and salts with unprecedentedly low membrane fouling through an eight-cycle continuous operation. Our results demonstrate that the electro-driven filtration process using nanoporous membranes as high-performance anion conducting membranes shows a critical potential in fractionation of organic dyes and inorganic salts, unlocking the proof of concept of nanoporous membranes in electro-driven application.
Obtaining the interaction between two substances in liquid through their molecular structures can promote the design and preparation of new functional materials. When multiple types of intermolecular forces coexist, whether the contribution terms generated by each type of intermolecular force have the same scaling factor is a key consideration. In this paper, an empirical equation for calculating the total intermolecular interaction is proposed. The required molecular property parameters for calculation can be obtained through quantum–chemical calculation. For the experiments of removing eight ionic dyes in water by using corn cobs as adsorbents, linear correlation was found between the removal percentage and the total interaction calculated from the proposed equation. When the scaling factors of polar and hydrogen bond interaction terms are 1, the scaling factor of dispersion force interaction term in the equation is greater than 2.5.