Mechanistic insights into the environmental fate of tetracycline affected by ferrihydrite: Adsorption versus degradation

Tetracycline-Induced Release and Oxidation of As(III) Coupled with Concomitant Ferrihydrite Transformation

“…This observation was consistent with published studies reporting a slight decrease in TC adsorption by Fh with an increase in pH . The point of zero charge of Fh has been reported to be ∼pH 7.8 . We also noticed that as the pH increased from 6.0 to 8.0, the speciation of TC changed from mainly neutral H 2 TC to anionic HTC – (Figure S11), increasing the electrostatic repulsion, which was not conducive to the adsorption of TC on Fh.…”

“…Previous studies have also reported that TC induces the reduction of Fh following the transfer of TC electrons to the surface of Fh, owing to its strong tendency to complex with mineral surfaces due to the structure of dimethylamino (−N­(CH 3 ) 2 ), amide (−CONH 2 ), and amine groups (−NH 2 ) (Figure S1). We also previously reported that hydroxylation, dealkylation, and deamination occurred in the Fh-TC system, and the dissolved oxygen (O 2 ) was not responsible for the Fh-induced degradation of TC . We considered that TC adsorbed on the Fh surface destabilizes the Fe–O bond in Fh, leading to the dissolution of Fe­(II) …”

“… We also previously reported that hydroxylation, dealkylation, and deamination occurred in the Fh-TC system, and the dissolved oxygen (O 2 ) was not responsible for the Fh-induced degradation of TC . We considered that TC adsorbed on the Fh surface destabilizes the Fe–O bond in Fh, leading to the dissolution of Fe­(II) …”

“…Therefore, the migration and transformation of As species coupled with iron (hydr)­oxides have a significant effect on the toxicity and activity of As in soil. Ferrihydrite (Fh) is a Fe mineral that exists widely in paddy soils with alternating dry and wet conditions . The higher redox reactivity and specific surface area associated with ferrihydrite influence the transformation and transport of As in soils. , …”

Pharmaceuticals removal by synergistic adsorption and S-scheme photocatalysis using nano-CeO2-coupled Fe3O4 on a CTAB matrix and investigation of the nanocomposite's antibacterial and antibiofilm activities: intrinsic degradation mechanism

“…Similar kinds of results were observed in the previous literature. 40 In another study, Yu et al 41 investigated biochar/MOFs and reported that there was a decrease in the tetracycline adsorption with the increase in the NaCl content. This study suggests that the adsorption capacity of NCs varied based on the adsorbent surface chemistry and property of the pollutants.…”