a Laboratory of Chemical Resources, Division of Sustainable Resources Engineering, Faculty of Engineering , Hokkaido University , Sapporo , Japan.
J Environ Sci Health A Tox Hazard Subst Environ Eng. 2014;49(4):365-75. doi: 10.1080/10934529.2014.854148.
Tetrabromobisphenol A (TBBPA) and tetrachlorobisphenol A (TCBPA), commercially used halogenated flame retardants, can be found in leachates from landfills, because hydrophobic interactions with humic acids (HAs), major organic components in landfills, result in an increase in their solubility. The oxidation characteristics of TBBPA and TCBPA in the presence of HA were compared using a catalytic system comprised of a combination of iron(III)-tetrakis(p-sulfophenyl)porphyrin (FeTPPS) and KHSO5 that can mimic the enzymatic reactions that occur in landfills. The levels of degradation and dehalogenation of TBBPA and TCBPA at pH 4 were significantly lower than at pH 8, which is a typical pH value for landfill leachates. In the presence of HA at pH 8, 2-hydroxyisopropyl-2,6 -dihalophenols (2HIP-26DXPs) were detected as major by-products. These compounds are likely produced via the β-carbon scission of the substrates, and their levels decreased with increasing reaction time. The levels of coupling compounds between 2,6-dihalopnenols and TBBPA or TCBPA increased with reaction time. The 27% of Br in the degraded TBBPA and 50% of Cl in the degraded TCBPA were incorporated into the HA as a result of catalytic oxidation via the FeTPPS/KHSO5 system. These results suggest that TCBPA is incorporated into HA more readily than TBBPA. The coupling compounds between HA and halogenated intermediates from TBBPA or TCBPA were assigned by pyrolysis-gas chromatography/mass spectrometry.
四溴双酚 A（TBBPA）和四氯双酚 A（TCBPA）是两种常用的卤化阻燃剂，可在垃圾填埋场的浸出液中被发现，这是由于它们与腐殖酸（HA）之间的疏水相互作用，HA 是垃圾填埋场中的主要有机成分，导致它们的溶解度增加。使用由铁（III）-四（对磺苯基）卟啉（FeTPPS）和 KHSO5 组成的催化体系，模拟垃圾填埋场中发生的酶促反应，比较了 TBBPA 和 TCBPA 在 HA 存在下的氧化特性。在 pH 值为 4 时，TBBPA 和 TCBPA 的降解和脱卤水平明显低于 pH 值为 8 时的水平，这是垃圾填埋场浸出液的典型 pH 值。在 pH 值为 8 时，HA 的存在下，检测到主要的副产物为 2-羟丙基-2,6-二卤代苯酚（2HIP-26DXPs）。这些化合物可能是通过底物的β-碳原子断裂产生的，其水平随反应时间的增加而降低。随着反应时间的增加，2,6-二卤代酚与 TBBPA 或 TCBPA 之间的偶联化合物的水平增加。通过 FeTPPS/KHSO5 体系的催化氧化，降解的 TBBPA 中 27%的 Br 和降解的 TCBPA 中 50%的 Cl 被整合到 HA 中。这些结果表明，TCBPA 比 TBBPA 更容易被整合到 HA 中。通过热解-气相色谱/质谱法对 HA 与 TBBPA 或 TCBPA 卤代中间体之间的偶联化合物进行了分配。
