Lanthanum carbonate hydroxide/magnetite nanoparticles functionalized porous biochar for phosphate adsorption and recovery: Advanced capacity and mechanisms study

Gas–Liquid Reactions to Synthesize Positively Charged Fe3O4 Nanoparticles on Polyurethane Sponge for Stable and Recyclable Adsorbents for the Removal of Phosphate from Water

“…Meanwhile, there is no Fe−P precipitation, meaning that electrostatic or physical adsorption has occurred. 70 Therefore, according to the above results, the reaction mechanism of Fe 3 O 4 nanoparticles accompanied by coordination can be depicted as follows: 35 − was also adsorbed by electrostatic attraction with (Fe-TEA) + . Thus, one can infer a better adsorption performance for GL-Fe 3 O 4 -TEA because of more adsorption sites (Figure 9).…”

“…After phosphate adsorption by GL-Fe 3 O 4 -NH 3 and GL-Fe 3 O 4 -TEA, the absorption peaks corresponding to the stretching vibration of Fe–OH groups at 1018 and 1019 cm –1 disappeared, and new intensive peaks appeared at 1042 and 1045 cm –1 , which could be assigned to the V 3 band vibrations of HPO 4 2– or H 2 PO 4 – . Especially in the FTIR data after adsorption, the band corresponding to a PO vibration (1097 and 1101 cm –1 ) and the band corresponding to a P–OFe vibration (993 and 992 cm –1 ) were found. ,, Besides, the peaks at 584 cm –1 , which correspond to Fe–O, changed to 589 (Figure a) and 592 (Figure b) cm –1 , respectively. The appearance of all of the above peaks indicated that ligand exchange between phosphate and hydroxyl groups was the dominant mechanism of phosphate adsorption on GL-Fe 3 O 4 .…”

“…Especially in the FTIR data after adsorption, the band corresponding to a P�O vibration (1097 and 1101 cm −1 ) and the band corresponding to a P−OFe vibration (993 and 992 cm −1 ) were found. 46,62,70 Besides, the peaks at 584 cm −1 , which correspond to Fe−O, changed to 589 (Figure 8a) and 592 (Figure 8b) cm −1 , respectively. The appearance of all of the above peaks indicated that ligand exchange between phosphate and hydroxyl groups was the dominant mechanism of phosphate adsorption on GL-Fe 3 O 4 .…”

“…According to the results of the adsorption experiments under different pH values and the ζ-potential test, the phosphate can also be adsorbed by electrostatic interaction, which can occur between positively charged surfaces of GL-Fe 3 O 4 and negatively charged phosphate ions, forming an outer-sphere complex. Meanwhile, there is no Fe–P precipitation, meaning that electrostatic or physical adsorption has occurred …”

Rapid and efficient removal of phosphate by La-doped layered double hydroxide/biochar from aqueous solution

“…43,44 BC, being a high surface area and porous material, provides a large reactive area for effective modification of hydroxides and reduces the aggregation of LDH. [45][46][47][48][49][50][51][52] Alagha et al 53,54 synthesized biochar-MgAl LDH and magnetic Mg-Fe/LDH intercalated activated carbon for phosphate and nitrate removal. Yang et al 55 combined Zn/Al-LDH and BC for the synthesis of the BC-Zn/Al-LDH composites, with a phosphate adsorption capacity of 152.1 mg g À1 .…”