Optimization of multi-stage velocity gradients in a cylindrical fluidized bed flocculator

Flocculation time is conventionally believed to be proportional to the fiocculation effciency of a cylindrical fluidized bed flocculator. However, in a single-stage velocity gradient situation, the flocculation efficiency decreases when the optimal flocculation time is exceeded. A multi-stage velocity gradient was established in a cylindrical fluidized bed flocculator, based on the hydraulic classification theory. This multi-stage velocity gradient fluidized bed flocculator （MGF） created a more suitable environment for floc growth and protection, which was confirmed by the size distribution of flocs along the bed height. Correspondingly, the abatement efficiencies for Kaolin slurry and dyed wastewater treatment in the MGF were enhanced by 5-10%, and by 7-20%, respectively, compared with those in the single-stage velocity gradient fluidized bed flocculators （SGFs）. The initial bed height distribution ratio along the velocity gradients was an important factor for MGF optimization.

透明超疏水材料的制备及其应用

超疏水材料由于其独特的非浸润性引起人们的广泛关注,近年来得到迅猛发展,各种适用于不同领域的功能性超疏水表面应运而生。其中,透明超疏水材料因其在光学领域的特殊贡献受到人们的青睐。透明疏水涂层技术对于实际应用具有重要的意义,透明涂层不仅可以满足光学器件防护的高透光率,还可以维持防护本体的基本外观,在自清洁、防污、防冰防雾、防腐蚀等领域都展示出广阔的应用前景。本文系统地阐述了超疏水表面以及其中功能性的透明超疏水表面的最新进展、表面的设计、制造和重要应用。尽管已经取得了重大进展,但是目前超疏水材料在耐久性方面还存在诸多问题,例如,容易被机械外力破坏、极端环境下表面的超疏水性质不稳定以及老化等问题,限制了透明疏水涂层技术的大范围应用。在未来的研究中,一方面继续丰富相关的理论知识,为透明疏水涂层技术的应用提供更多的理论支持,另一方面,提高涂层的透明度和机械耐久性能仍是未来研究的重中之重。