Fabrication of porous materials using quinoa husk and attapulgite co-stabilized foam templates for dye adsorption and post-treatment of soil remediation

Water-based foam has great potential in the preparation of porous materials, but there is still a lack of green and simple preparation methods. In this study, a stable water-based foam that co-stabilized with saponin leached from agricultural waste quinoa husk (QH) and nano-clay attapulgite (APT). The thickening effect and interface stability of modified APT played a crucial role in the formation and stabilization of Pickering foam. The free radical polymerization occurred in the continuous phase without affecting the foam stability, and the obtained pore-rich adsorbent displayed high-performance adsorption for methylene blue and methyl violet, with the adsorption capacities reaching up to 291.95mg/g and 430.01mg/g, respectively. In keeping with the idea of sustainable development, the spent adsorbent was pyrolyzed and converted into mineral biochar. The pot experiments showed that the mineral biochar could improve the soil properties and promoted the plant growth. This work provides a new approach to the production of green and stable Pickering foam and also an alternative to realize the sustainable high value utilization of waste QH.