Figure 1.

Photographs showing the production and characterization of superhydrophobic sand (SHS) and engineered biochar (EB). (A–C) thermal combination of silica sands and paraffin wax (1000:1 ratio) to produce SHS with conformal coating of sand grains using thin layer of wax; (D, E) scanning electron microscope (SEM) and macroscale images demonstrating the water-repellent (superhydrophobic) behavior of the SHS by moisture droplets on sand grains. (F, G) date palm biomass converted to biochar using a batch pyrolysis reactor at > 500°C; (H) post-processed biochar modified into EB by grinding to smaller particles followed by nutrient enrichment (i.e., loading with macro- and micronutrients). (I) SEM images of EB at 100 μm and 10 μm (Inset) showing the highly porous structure of the biochar alongside xylem and tracheids. Note: Panels (D, E) were adapted from our previous work: (Gallo Jr et al., 2022).