Zero-valent iron/persulfate(Fe0/PS) oxidation acetaminophen in water|
Deng, J.; Shao, Y.; Gao, N.; Deng, Y.; Tan, C. & Zhou, S.
Zero-valent iron (Fe0), as an alternative iron
source, was evaluated to activate persulfate (PS) to degrade
acetaminophen (APAP), a representative pharmaceutically
active compound in water. Effects of key factors in the
so-called Fe0/PS process, including Fe0 dosage, initial pH,
temperatures and chelating agents, were studied. Under all
the conditions tested, the APAP degradation followed a
pseudo-first-order kinetics pattern. The degradation efficiency
of APAP was highest when the Fe0 to PS molar ratio
increased to 1:1, and the degradation rate constant and
removal were 23.19 × 10-3 min-1 and 93.19 %, respectively.
Comparing with Fe2+, Fe0 served as an alternative
iron source that can gradually release Fe2+ into water,
thereby consistently activating PS to produce sulfate radicals.
The Fe0/PS system was effective in a broader pH
range from 3 to 8.5. Heat could facilitate production of
sulfate radicals and enhance the APAP degradation in the
Fe0/PS system. High reaction temperature also improved
the Fe2+/PS oxidation of APAP. Finally, sodium citrate
(a chelating agent) at an appropriate concentration could
improve the APAP degradation rate in the Fe2+/PS and
Fe0/PS system. The optimal molar ratio of Fe0 to citrate
depended on solution pH. Our results demonstrated that
Fe0 was an alternative iron source to activate PS to degrade
APAP in water.
Affecting factors; pH; Sodium citrate; Sulfate radicals; Temperature