Effective Removal of Phosphate from Waste Water Based on Silica Nanoparticles

Figure 1

The SiO₂ extraction process. Note. (a) Rice husk ash; (b) filtering solution from rice husk ash diluted in sodium hydroxide; (c) precipitation by acid; (d) SiO₂ powder.

(a)

(b)

(c)

(d)