Efficient removal of trifluoroacetic acid from water using surface-modified activated carbon and electro-assisted desorption.
J Hazard Mater
; 436: 129051, 2022 08 15.
Article
em En
| MEDLINE
| ID: mdl-35580494
ABSTRACT
Trifluoroacetic acid (TFA) is a very persistent, very mobile substance (vPvM) with potential toxicity, and causes increasing environmental concerns worldwide. Conventional wastewater treatment strategies are inefficient for selective TFA removal in the presence of inorganic anions. Here we show that surface defunctionalized activated carbon felt (DeACF) carrying anion exchange sites exhibits an outstanding adsorption efficiency towards TFA thanks to introduced electrostatic attraction and enhanced interactions between hydrophobic carbon surface and CF3 moieties (qmax = 30 mg/g, Kd = (840 ± 80) L/kg at cTFA = 3.4 mg/L in tap water). Flow-cell experiments demonstrated a strongly favored TFA uptake by DeACF from tap water over Cl- and SO42- but a remarkable co-adsorption of the inorganic water contaminant NO3-. Electro-assisted TFA desorption using 10 mM Na2SO4 as electrolyte and oxidized ACF as anode showed high recoveries of ≥ 87% at low cell voltages (< 1.1 V). Despite an initial decrease in TFA adsorption capacity (by 33%) caused by partial surface oxidation of DeACF after the 1st ad-/desorption cycle, the system stability was fully maintained over the next 4 cycles. Such electro-assisted 'trap&release' approach for TFA removal can be exploited for on-site regenerable adsorption units and as a pre-concentration step combined with degradation technologies.
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Texto completo:
1
Coleções:
01-internacional
Contexto em Saúde:
2_ODS3
Base de dados:
MEDLINE
Assunto principal:
Poluentes Químicos da Água
/
Purificação da Água
Idioma:
En
Revista:
J Hazard Mater
Ano de publicação:
2022
Tipo de documento:
Article