Simultaneous Recovery of Display Panel Waste Glass and Wastewater Boron by Chemical Oxo-precipitation with Fluidized-Bed Heterogeneous Crystallization

Silica-based carrier is a promising material for recovery of metal and nonmetal contaminants in chemical oxo-precipitation-fluidized bed crystallization (COP-FBC) system. Boron species are an essential element for plant growth and can cause health concerns in human beings at high concentrations in water environments. The composition of thin-film transistor liquid crystal display (TFT-LCD) contains a wide variety of metal oxides and can be tailored as promising functional mesoporous carriers for boron crystallization recovery in the presence of barium ions and hydrogen peroxide. In this study, waste-derived mesoporous aluminosilicate (MAS) nanomaterial in the presence of barium ions and hydrogen peroxide was used as a carrier for sustainable recovery of crystallized boron, a priority wastewaters pollutant. The MAS shows the hierarchically homogeneous distribution of nanostructured aluminosilicate particles with an average size of 12.8 +/- 3.6 nm on the surface after the activation with Na2CO3 at 1000 degrees C. Moreover, the negatively charged surface and the mesoporous structure of MAS enhance the adsorption of Ba2+ onto MAS, and the Langmuir adsorption capacity of 105 mg/g is achieved, which is conducive to the enhancement of the recovery of boron species. Moreover, the recovery efficiency and crystallization ratio of boron by MAS can be up to 84.5 and 93.4%, respectively. The cross-sectional scanning electron microscopy images and the high-temperature X-ray diffraction results confirm the boron recovery mechanism that the negatively charged functional group as well as the mesoporosity of MAS triggers the rapid formation of needle-shaped precipitates of barium peroxoborate, and then converted to barium borate after calcination at 1050 degrees C. Results obtained in this study clearly demonstrate the possibility of fabricating environmentally benign mesoporous aluminosilicate adsorbents from TFT-LCD waste to sustainably recover and crystallize boron species from water and wastewater in COP-FBC.