V.V. Voevodsky Institute of Chemical Kinetics and Combustion, 3 Institutskaya str., 630090, Novosibirsk, Russian Federation; Novosibirsk State University, 2 Pirogova St., 630090, Novosibirsk, Russian Federation.
Novosibirsk State University, 2 Pirogova St., 630090, Novosibirsk, Russian Federation; International Tomography Center, 3a Institutskaya str., 630090, Novosibirsk, Russian Federation.
Chemosphere. 2018 Mar;195:839-846. doi: 10.1016/j.chemosphere.2017.12.096. Epub 2017 Dec 16.
In the present work advances and limitations in the application of Fe(III)-oxalate complexes (namely, [Fe(Ox)]) to the photodegradation of a model persistent organic contaminant - 2,4-dichlorophenoxybutanoic acid (2,4-DB) in neutral aqueous solutions were systematically investigated for the first time. It has been shown that the efficiency of [Fe(Ox)] system greatly depends on the initial concentrations of oxalate ion due to the fast consumption of the ligand during photodegradation process leading to the formation of photochemically less active Fe(III) species. Efficiency of Fe(Ox) system normalized to UVA absorption at the excitation wavelength is practically independent on [Fe(III)]. Thus, it is highly probable that concentrations of Fe(III) as low as < 10 M could be applied in water treatment procedures using reactors with very long optical path. The system also keeps high efficiency at low concentration of pollutant (<10 M) though this results in higher relative consumption rate of Fe(III) and oxalate ions.
本工作首次系统地研究了 Fe(III)-草酸盐配合物（即[Fe(Ox)]）在中性水溶液中光降解模型持久性有机污染物-2,4-二氯苯氧丁酸（2,4-DB）的应用中的进展和局限性。研究表明，由于配体在光降解过程中快速消耗，导致光化学活性较低的 Fe(III)物种形成，[Fe(Ox)]体系的效率极大地取决于草酸盐离子的初始浓度。归一化到激发波长处 UVA 吸收的 Fe(Ox)体系的效率与[Fe(III)]基本无关。因此，在使用具有非常长光程的反应器的水处理程序中，极有可能应用浓度低至<10 M 的 Fe(III)。尽管这会导致 Fe(III)和草酸盐离子的相对消耗率更高，但该体系在低浓度污染物（<10 M）下仍保持高效率。
