School of Civil and Environmental Engineering , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States.
Department of Environment and Occupational Health, School of Public Health , Texas A&M University , College Station , Texas 77843 , United States.
Environ Sci Technol. 2019 May 7;53(9):5272-5281. doi: 10.1021/acs.est.9b00006. Epub 2019 Apr 11.
Destruction of pharmaceuticals excreted in urine can be an efficient approach to eliminate these environmental pollutants. However, urine contains high concentrations of chloride, ammonium, and bicarbonate, which may hinder treatment processes. This study evaluated the application of ferrate(VI) (FeO, Fe(VI)) to oxidize pharmaceuticals (carbamazepine (CBZ), naproxen (NAP), trimethoprim (TMP), and sulfonamide antibiotics (SAs)) in synthetic hydrolyzed human urine and uncovered new effects from urine's major inorganic constituents. Chloride slightly decreased pharmaceuticals' removal rate by Fe(VI) due to the ionic strength effect. Ammonium (0.5 M) in undiluted hydrolyzed urine posed a strong scavenging effect, but lower concentrations (≤0.25 M) of ammonium enhanced the pharmaceuticals' degradation by 300 μM Fe(VI), likely due to the reactive ammonium complex form of Fe(V)/Fe(IV). For the first time, bicarbonate was found to significantly promote the oxidation of aniline-containing SAs by Fe(VI) and alter the reaction stoichiometry of Fe(VI) and SA from 4:1 to 3:1. In depth investigation indicated that bicarbonate not only changed the Fe(VI)/SA complexation ratio from 1:2 to 1:1 but provided a stabilizing effect for Fe(V) intermediate formed in situ, enabling its degradation of SAs. Overall, the results of this study suggested that Fe(VI) is a promising oxidant for the removal of pharmaceuticals in hydrolyzed urine.
破坏尿液中排泄的药物可能是消除这些环境污染物的有效方法。然而，尿液中含有高浓度的氯、铵和碳酸氢盐，这可能会阻碍处理过程。本研究评估了高铁酸盐（VI）（FeO、Fe（VI））在合成水解人尿中氧化药物（卡马西平（CBZ）、萘普生（NAP）、甲氧苄啶（TMP）和磺胺类抗生素（SAs））的应用，并揭示了尿液主要无机成分的新作用。由于离子强度效应，氯略微降低了 Fe（VI）对药物的去除率。未稀释水解尿中的铵（0.5 M）具有很强的清除作用，但较低浓度（≤0.25 M）的铵通过 300 μM Fe（VI）增强了药物的降解，这可能是由于形成了具有反应性的铵络合形式的 Fe(V)/Fe(IV)。首次发现碳酸氢盐能显著促进 Fe(VI)氧化含苯胺的 SAs，并改变 Fe(VI)和 SA 的反应计量比从 4:1 变为 3:1。深入研究表明，碳酸氢盐不仅改变了 Fe(VI)/SA 的络合比从 1:2 变为 1:1，而且为原位形成的 Fe(V)中间物提供了稳定作用，从而使其能够降解 SAs。总的来说，本研究结果表明，Fe（VI）是一种很有前途的用于去除水解尿中药物的氧化剂。
