Adsorptive performance of Ni(II) from aqueous solutions using biochar made of phragmites australis by adding ammonium polyphosphate as flame retardant

Abstract

The withered Phragmites australis (PA) surrounding the rivers can cause the secondary pollution of water. In this research, by changing the ratio (R) of ammonium polyphosphate (APP), used as flame retardant, to PA at different temperatures, a series of BC samples were prepared for further analysis in several perspectives, namely, surface morphologies, surface areas, surface functional groups, and yields. The analysis indicated that, after being charred, the produced BCs obtained enhanced yields and promoted surface acidity. As adsorbent to remove Ni(II) from aqueous solutions, the BCs with APP improved the sorption of Ni(II) dramatically, compared with those purely produced by pyrolysis of PA, and obtained the maximum of adsorption capacity with the R of 0.25 at 400°C.