Dehalogenation of Iodinated X-ray Contrast Media in a Bioelectrochemical System

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• 作者：Yang Mu ; Jelena Radjenovic ; Jinyou Shen ; Ren茅 A. Rozendal ; Korneel Rabaey ; J眉rg Keller
• 刊名：Environmental Science & Technology
• 出版年：2011
• 出版时间：January 15, 2011
• 年：2011
• 卷：45
• 期：2
• 页码：782-788
• 全文大小：256K
• 年卷期：v.45,no.2(January 15, 2011)
• ISSN：1520-5851

文摘

Iodinated X-ray contrast media (ICM) are only to a limited extent removed from conventional wastewater treatment plants, due to their high recalcitrance. This work reports on the cathodic dehalogenation of the ICM iopromide in a bioelectrochemical system (BES), fed with acetate at the anode and iopromide at the cathode. When the granular graphite cathode potential was decreased from 鈭?00 to 鈭?50 mV vs standard hydrogen electrode (SHE), the iopromide removal and the iodide release rates increased from 0 to 4.62 卤 0.01 mmol m^鈭? TCC d^鈭? and 0 to 13.4 卤 0.16 mmol m^鈭? TCC d^鈭? (Total Cathodic Compartment, TCC) respectively. Correspondingly, the power consumption increased from 0.4 卤 1 to 20.5 卤 3.3 W m^鈭? TCC. The Coulombic efficiency of the iopromide dehalogenation at the cathode was less than 1%, while the Coulombic efficiency of the acetate oxidation at the anode was lower than 50% at various granular graphite cathode potentials. The results suggest that iopromide could be completely dehalogenated in BESs when the granular graphite cathode potential was controlled at 鈭?00 mV vs SHE or lower. This finding was further confirmed using mass spectrometry to identify the dehalogenated intermediates and products of iopromide in BESs. Kinetic analysis indicates that iopromide dehalogenation in batch experiments can be described by a first-order model at various cathode potentials. This work demonstrates that the BESs have a potential for efficient dehalogenation of ICM from wastewater or environmental streams.