Heterogeneous photodegradation of bisphenol A with iron oxides and oxalate in aqueous solution
Heterogeneous photodegradation of bisphenol A with iron oxides and oxalate in aqueous solution
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DOI：
10.1016/j.jcis.2007.03.067
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发表时间：
2007-07-15
影响因子：
9.9
通讯作者：
Dong, J.
中科院分区：
文献类型：
--
作者：
Li, F. B.;Li, X. Z.;Dong, J.
为了解铁氧化物和聚羧酸在自然环境中对内分泌干扰物（EDCs）的降解情况，研究了双酚A（BPA）在铁氧化物界面上的紫外光降解。通过水热法制备四种铁氧化物，然后在65、280、310和420摄氏度的不同温度下烧结，分别命名为“IO-65”、“IO-280”、“IO-310”和“IO-420”。采用X射线衍射（XRD）和BET法对所制备的铁氧化物进行了表征。IO-65的XRD图案显示纤铁矿（γ-FeOOH）的晶体结构，IO-420的XRD图案显示赤铁矿（α-Fe 2 O3）的晶体结构，而IO-280和IO-310具有磁赤铁矿（γ-Fe 2 O3）和赤铁矿的混合晶体结构。BET结果表明，随着烧结温度的升高，比表面积逐渐减小。结果表明，BPA的光降解强烈地依赖于铁氧化物和草酸盐的性质，和pH值。铁氧化物的性质强烈地影响BPA的降解对草酸盐浓度的依赖性。在紫外光照射下，草酸盐降解BPA的最佳初始浓度分别为2.0、2.0、2.4和2.0 mM（10- 65、10 - 280、10 -310和10-420）。在最佳草酸盐初始浓度下，紫外光照射下BPA降解的一级动力学常数k为IO-280 > IO-310 > 10-65 > 10-420。实验表明，最佳pH值应在3-4之间。此外，BPA降解的依赖性还应归因于溶液中溶解的草酸铁和铁氧化物表面吸附的草酸铁的形成，以及过氧化氢的形成。(c)2007年爱思唯尔公司All rights reserved.
To understand the degradation of endocrine disrupting chemicals (EDCs) with existence of iron oxides and polycarboxylic acids in the natural environment, the photodegradation of bisphenol A (BPA) at the interface of iron oxides under UV illumination was conducted. Four iron oxides were prepared by a hydrothermal process and then sintered at different temperatures of 65, 280, 310, and 420 degrees C named "IO-65," "IO-280," "IO-310," and "IO-420," respectively. The prepared iron oxides were characterized by X-ray diffraction (XRD) and Brunauer-Emmett-Teller (BET) methods. The XRD pattern of IO-65 showed a crystal structure of lepidocrocite (gamma-FeOOH) and that of IO-420 demonstrated a crystal structure of hematite (alpha-Fe203), while IO-280 and IO-310 have the mixed crystal structures of maghemite (gamma-Fe2O3) and hematite. The BET results revealed that the specific surface areas decreased with the increase of sintering temperature. The results demonstrated that the photodegradation of BPA depends strongly on the properties of iron oxides and oxalate, and pH. The properties of iron oxides influenced strongly the dependence of the BPA degradation on the oxalate concentration. The optimal initial concentrations of oxalate for BPA degradation under UV illumination were determined to be 2.0,2.0,2.4, and 2.0 mM for 10-65,10-280,10-310, and 10-420, respectively. The first-order kinetic constants k for BPA degradation under UV illumination in the presence of oxalate with the optimal initial concentration are ranked as IO-280 > IO-310 > 10-65 > 10-420. The experiments demonstrated that the optimal pH value should be in the range of 3-4. Furthermore, the dependence of BPA degradation should be also attributable to the formation of the dissolved Fe-oxalate in the solution and the adsorbed Fe-oxalate on the surface of iron oxides, and also the formation of hydrogen peroxide. (c) 2007 Elsevier Inc. All rights reserved.