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Advisor(s)
Abstract(s)
Activated carbons (ACs) have been used as metal supports for catalytic wet peroxide
oxidation (CWPO) of organic compounds. A shortcoming is that added metals can undergo leaching,
leading to catalyst deactivation and secondary contamination of the treated water. In the present
study, CWPO of phenol aqueous solutions was investigated in the presence of five commercial
ACs without added metals yet containing di erent extents of iron impurities resulting from their
industrial preparation procedures (ROX 0.8, RX 3-Extra, C-Gran and PK 0.25-1 from Cabot Norit
and HYDRAFFIN AS 12/450 from Degussa). Application of as-received ROX 0.8 leads to the best
compromise between removals of phenol (79%) and total organic carbon (TOC; 50%) and iron leaching
(0.22 mg L1). In-house-modified ROX 0.8 materials, obtained by thermal treatment under inert
atmosphere followed by activation under oxidative atmosphere, were also tested. The activity of ROX
0.8 oxidized at 673 K (ROXN673) was the highest among these materials (92% and 57% of phenol and
TOC removals, respectively) and with iron leaching (0.67 mg L1) well below the limits established
by European regulations for discharge of treated waters. This enhanced performance was mainly
explained by the more developed porous structure and higher specific surface area (SBET) of ROXN673,
thus promoting better accessibility to iron impurities, which act as active sites for CWPO at the surface
of the catalyst.
Description
Keywords
Advanced oxidation processes (AOPs) CWPO Heterogeneous Fenton process Carbon materials Catalytic activity Wastewater treatment Phenol Environmental protection Water
Citation
Pinho, Maria T.; Ribeiro, Rui S.; Gomes, Helder T.; Faria, Joaquim L.; Silva, Adrián (2020). Screening of activated carbons for the treatment of highly concentrated phenol solutions using catalytic wet peroxide oxidation: the effect of iron impurities on the catalytic activity. Catalysts. ISSN 2073-4344. 10:11, p. 1-14