Characterization and photocatalytic activity of the biochar converted from the Acrostichum aureum Linn. biomass

Abstract

In the present study, Acrostichum aureum Linn. (AAL) was proved as an accumulator of iron and a potential candidate to remove iron pollutants from groundwater. The iron-loaded biochar converted from the iron-contaminated AAL plants was determined the characterization and photocatalytic activity to demonstrate the potential for reusing the AAL biomass enriched with iron. In a 47-day hydroponic experiment, AAL plants could steadily grow in 20.0 mg L-1 Fe(NO3)(3) solutions and pH ranging from 6.0 to 7.0. The total amount of iron introduced into the phytoremediation system is 240 mg iron, of which the AAL plants accumulate about 70%. X-ray diffraction (XRD) analysis showed that the iron-enriched biochar (named Fe-Bio-C) mainly consists of alpha-Fe2O3, and the Fe content determined by EDX is around 23 wt%. BET results revealed that the iron-enriched biochar possesses a higher specific surface area, around 266.9 m(2) g(-1), compared to the original biochar, around 18.2 m(2) g(-1). The photocatalytic performance of the Fe-Bio-C was studied in the discoloration of methyl orange (MO), with a maximum MO removal capacity of 18.8 mg g(-1). These findings show the phytoaccumulation of Acrostichum aureum Linn. plants to remove iron pollutants from groundwater and the potential application of the iron-accumulated biomass.