Simultaneous removal of phosphate and nitrite ions from aqueous solutions using modified soybean waste

We investigated the simultaneous removal of phosphate and nitrite ions from aqueous solutions by a combination treatment that used both PG-Ca (poly-γ-glutamic acid combined with flocculating agents) and SB600 (soybeans treated with calcium chloride, hydrochloric acid and calcined at 600 °C). Phosphate ions and nitrite ions were selectivity adsorbed by PG-Ca and SB600, respectively. The removal mechanism of phosphate ions from aqueous solution was related to the presence of calcium hydroxide (derived from PG-Ca), and that of nitrite ions was related to the presence of chloride ions at the surface of SB600.

Graphical abstractAmount of nitrogen and phosphorus before and after adsorption.Figure optionsDownload full-size imageDownload as PowerPoint slide