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Comparison of UV-C irradiation, ozonation, and iron chelates treatments for degradation of tetracycline in water
Ziółkowska, A.; Margas, M.; Grajek, H.; Wasilewski, J.; Adomas, B.; Michalczyk, D. & Piotrowicz-Cieślak, A. I.
Abstract
The objective of this study was to propose a
method for efficient degradation of tetracycline as a water
contaminant. UV-C rays, ozonation, and iron chelates were
used for removal of tetracycline from water. Aqueous
solution of tetracycline (5 × 10-5 M) was exposed to UV-C
rays (in two doses—6 and 12 W), ozonation (at 6–12 mg
ozone), or iron chelates: iron(III) sodium ethylenediaminetetraacetate,
iron(III) trisglycinate, and iron(III)
citrate. For each of iron compounds, three doses were
studied: 2.5 × 10-5 M, 5 × 10-5 M, 10 × 10-5 M. The
experiments have shown that aqueous solution of tetracycline
(5 × 10-5 M) is immediately degraded as a result of
ozonation with 12 mg ozone. Absorbance of tetracycline
decreased from A = 0.78 to A = 0.35 after 20-min ozone
treatment of sample. The fluorescence spectra revealed the
presence of two ozone-induced TC degradation products
with fluorescence maxima at 523 and 531 nm appearing
immediately after the ozonation treatment. On the other
hand, iron(III) sodium ethylenediaminetetraacetate and
iron(III) trisglycinate gave rise to a single TC degradation
product with a fluorescence maximum at 531 nm, observed
after 10 days of the experiment. On application of iron(III)
trisglycinate, at any studied concentration, tetracycline
becomes degraded faster—in 4 days. Iron(III) citrate
degraded 90 % of tetracycline, when used at the level
10 × 10-5 M. The biggest changes in tetracycline concentration
were obtained as a result of ozonation and iron(
III) citrate treatments.
Keywords
Antibiotic; Contamination; Iron(III) citrate; Iron(III) sodium ethylenediaminetetraacetate; Iron(III) trisglycinate
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