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

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(NO 3 ) 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 α -Fe 2 O 3 , 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.