Pagano M, Lopez A, Volpe A, Mascolo G, Ciannarella R
Consiglio Nazionale delle Ricerche, Istituto di Ricerca Sulle Acque, Bari, Italy.
Environ Technol. 2008 Apr;29(4):423-33. doi: 10.1080/09593330801983862.
The oxidation of 10 nonionic surfactants (6 alcohol ethoxylates and 4 alkylphenol ethoxylates) by Fenton and H2O2/UV processes was investigated in synthetic (deionized water) and real aqueous matrices, i.e. secondary effluent from municipal wastewater treatment plant and groundwater. Batch tests were carried out to assess the optimal dosages of reagents leading to the total removal of surfactants. Regardless to the specific surfactant, both Fenton and H2O2/UV treatments of synthetic solutions containing one single surfactant (C0=14 mg l(-1)) always caused its rapid and quantitative removal (96-99%) with a corresponding very low (0-18%) TOC decrease. Only for the Fenton treatment, linear relationships were found between the amounts of H2O2 and Fe2+ necessary for surfactant removal and the ethoxy chain length of each surfactant. Conversely, in the case of H2O2/UV treatment the H2O2 dosage causing the quantitative oxidation of the treated surfactant depended on the length of both chains: the ethoxy and the hydrophobic one. Mixtures of the 10 surfactants (1.4 mg l(-1) each) were treated in both synthetic and real matrices. These latter were different in the case of Fenton (i.e. municipal secondary effluent) or H2O2/UV (i.e. real groundwater) treatments. Fenton treatment of municipal secondary effluent containing the surfactants mixture led to its total removal when a molar ratio [Total surfactants]/[H2O2]/[Fe2+] equal to 1/17/12 was used. As for H2O2/UV treatment of real groundwater samples, quantitative removal of surfactants mixture was achieved with a molar ratio [Total surfactants]/[H2O2] equal to 1/7.4. Surfactants mixture removals, if compared in deionized water and in real matrices, showed the same matrix effect during both treatments, i.e. less amounts of reagents were always required in synthetic solutions.
研究了10种非离子表面活性剂（6种醇乙氧基化物和4种烷基酚乙氧基化物）在合成（去离子水）和实际水基质中，即城市污水处理厂二级出水和地下水中，通过芬顿法和H₂O₂/UV工艺的氧化情况。进行了批次试验以评估实现表面活性剂完全去除所需的试剂最佳剂量。无论具体的表面活性剂如何，对含有单一表面活性剂（C₀ = 14 mg l⁻¹）的合成溶液进行芬顿法和H₂O₂/UV处理，总能使其快速且定量地去除（96 - 99%），同时总有机碳（TOC）相应降低幅度非常小（0 - 18%）。仅对于芬顿处理，发现去除表面活性剂所需的H₂O₂和Fe²⁺量与每种表面活性剂的乙氧基链长度之间存在线性关系。相反，在H₂O₂/UV处理的情况下，导致被处理表面活性剂定量氧化的H₂O₂剂量取决于两条链的长度：乙氧基链和疏水链。在合成和实际基质中对10种表面活性剂的混合物（每种1.4 mg l⁻¹）进行了处理。在芬顿处理（即城市二级出水）或H₂O₂/UV处理（即实际地下水）的情况下，这些实际基质有所不同。当使用摩尔比[总表面活性剂]/[H₂O₂]/[Fe²⁺]等于1/17/12时，对含有表面活性剂混合物的城市二级出水进行芬顿处理可使其完全去除。至于对实际地下水样品进行H₂O₂/UV处理，当摩尔比[总表面活性剂]/[H₂O₂]等于1/7.4时，可实现表面活性剂混合物的定量去除。如果在去离子水和实际基质中比较表面活性剂混合物的去除情况，在两种处理过程中均显示出相同的基质效应，即在合成溶液中始终需要更少剂量的试剂。
