Displacement of five metals sorbed on kaolinite during treatment with modified Fenton's reagent.
Displacement of five metals sorbed on kaolinite during treatment with modified Fenton's reagent.
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DOI：
10.1016/j.watres.2005.04.064
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发表时间：
2005-08
期刊：
影响因子：
12.8
通讯作者：
Mary Jo Monahan;A. Teel;R. Watts
中科院分区：
文献类型：
--
作者：
Mary Jo Monahan;A. Teel;R. Watts
以高岭土为吸附剂，研究了改性芬顿试剂处理土壤和地下水过程中对镉、铜、铅、镍和锌等5种常见金属污染物的吸附行为。改良的芬顿条件包括三种H2 O2浓度（0.9，1.8，2.7 M）和两种催化剂：可溶性铁（III）在pH 3和铁（III）-NTA螯合物在pH 6。铁（III）催化的芬顿反应释放出大量的锌、镉和铜。改性芬顿的铁（III）-NTA催化的反应释放锌，镉，铜和铅，并导致更大量的金属释放比铁（III）催化的反应。金属释放可能是由传播反应产生的瞬时氧物质（如超氧化物）介导的，在使用的过氧化氢浓度相对较高时，这种氧物质占主导地位。当保持足够低的过氧化氢浓度以最大限度地减少传播反应时，从高岭石中释放的金属是无法检测到的。这些结果表明，使用稀释浓度的过氧化氢芬顿的ISCO可以最大限度地减少潜在的金属流动性时，处理污染的土壤和地下水含有有机和金属污染物的混合物。
The displacement of sorbed metals during the treatment of soils and groundwater with modified Fenton's reagent was investigated using five common metal contaminants (cadmium, copper, lead, nickel, and zinc) and kaolinite as a model sorbent. Modified Fenton's conditions included three H2O2concentrations (0.9, 1.8, 2.7M) and two catalysts: soluble iron (III) at pH 3 and iron (III)–NTA chelate at pH 6. Iron (III)-catalyzed Fenton's reactions released significant amounts of zinc, cadmium, and copper. Modified Fenton's reactions catalyzed by iron (III)–NTA released zinc, cadmium, copper, and lead, and resulted in greater amounts of metals release than the iron (III)-catalyzed reactions. Metals release may have been mediated by transient oxygen species, such as superoxide, generated by propagation reactions, which become dominant at the relatively high hydrogen peroxide concentrations used. Metals release from kaolinite was undetectable when sufficiently low hydrogen peroxide concentrations were maintained to minimize propagation reactions. These results indicate that using dilute concentrations of hydrogen peroxide for Fenton's ISCO may minimize potential metals mobility when treating contaminated soils and groundwater containing a mixture of organic and metal contaminants.