Electro activation of persulfate using iron sheet as low-cost electrode: the role of the operating conditions.
Environ Technol
; 39(9): 1208-1216, 2018 May.
Article
in En
| MEDLINE
| ID: mdl-28443369
ABSTRACT
This work assesses the role of the operational conditions upon the electro-activation of persulfate (PS) using sacrificed iron electrode as a continuous low-cost Fe2+ source. An aqueous phenol solution (100â
mgâ
L-1) was selected as model effluent. The studied variables include current density (1-10â
mAâ
cm-2), persulfate concentration (0.7-2.85â
gâ
L-1), temperature (30-90°C) and the solution conductivity (2.7-20.7â
mSâ
cm-1) using Na2SO4 and NaCl as supporting electrolyte. A mineralization degree of around 80% with Na2SO4 and 92% in presence of NaCl was achieved at 30°C using 2.15â
gâ
L-1 PS at the lowest current density tested (1â
mAâ
cm-2). Besides PS concentration, temperature was the main variable affecting the process. In the range of 30-70°C, it showed a positive effect, achieving TOC conversion above 95% (using Na2SO4 under the previous conditions) along with a significant increase in iron sludge, which adversely affects the economy of the process. A lumped and simplified kinetic model based on persulfate consumption and TOC mineralization is suggested. The activation energy obtained for the TOC decay was 29â
kJâ
mol-1. An estimated operating cost of US$ 3.00 per m3 was obtained, demonstrating the economic feasibility of this process.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Sulfates
/
Water Purification
/
Iron
Type of study:
Health_economic_evaluation
/
Prognostic_studies
Language:
En
Journal:
Environ Technol
Journal subject:
SAUDE AMBIENTAL
/
TOXICOLOGIA
Year:
2018
Document type:
Article
Affiliation country:
España