Effects of Temperature and Acidic Pre-Treatment on Fenton-
Driven Oxidation of MTBE-Spent Granular Activated Carbon

to
Solid

(2)

Pore

(3)

Film

(4)

Bulk

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Abstract

The effects of temperature and acidic pre-treatment
on Fenton-driven chemical oxidation of methyl tert-
butyl ether (MTBE)-spent granular activated carbon
(GAC) were investigated. Limiting factors m MTBE
removal in GAC include the heterogeneous
distribution of amended iron and slow intra-particle
diffusive transport of MTBE and hydrogen peroxide
(H202) into the "reactive zone."'

Acid pre-treatment of GAC before iron amendment
altered the surface chemistry of the GAC, lowered
the pFl point of zero charge, and resulted in greater
penetration and more uniform distribution of iron in
GAC. This led to a condition where iron, MTBE, and
H202 co-existed over a larger volume of the GAC,
contributing to greater MTBE oxidation and removal.

H202 reaction and MTBE removal in GAC increased
with temperature. Modeling H202 transport and
reaction in GAC indicated that H202 penetration was
inversely proportional with temperature and tortuosity,
and occurred over a larger fraction of the total volume
of small GAC particles (0.3 milllimeters [mm] diameter) relative to large particles (1.2 mm diameter). Acidic pre-
treatment of GAC, iron amendment, elevated reaction temperature, and use of small GAC particles are operational
parameters that improve Fenton-driven oxidation of MTBE in GAC.





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# Contaminant (MTBE)

Schematic of the proposed mechanisms of (1) intra-particle MTBE mass
transfer (desorption), (2) MTBE diffusive mass transport (pore + surface),
intra-particle diffusive transport of H202, (3) MTBE diffusive transport
outward through the quiescent film, H2O2 diffusive transport from the bulk
solution through the quiescent film into the GAC pores, and (4) MTBE and
H202 mixing in bulk solution. Fenton-driven regeneration of GAC involves
the simultaneous occurrence of these mechanisms.

Products

Kan, E. and Ftuling, S.G. (2009). "Effects of Temperature and Acidic Pre-Treatment on Fenton-Driven Oxidation
of MTBE-Spent Granular Activated Carbon." Environmental Science and Technology, 43, 5: 1493-1499.

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