Endocrine disrupting chemicals (EDCs) have received substantial attention over the past decade because of the adverse effects of these chemicals on human health. In the present study, a novel hybrid system combining nanofiltration (NF) with homogeneous catalytic oxidation was developed for the effective degradation of EDCs in sources of drinking water. Bisphenol-A (BPA) was chosen as a model EDC and iron(III)-tetrasulfophthalocyanine (Fe(III)-TsPc) was used as a homogeneous metal catalyst to degrade BPA in the presence of hydrogen peroxide. In batch tests, it was confirmed that monomeric Fe(III)-TsPc was generated under weakly acidic conditions (pH < 4.5) and possessed remarkable catalytic activity-more than 90% of BPA was decomposed within 3 min at pH 4.5. Also, based on GC/MS and LC/MS, compounds such as p-benzoquinone, 4-isopropenyl phenol, BPA-o-quinone, and 4-hydroxyphenyl-2-propanol were identified as reaction intermediates and/or by-products of BPA oxidation, which could further be converted to low molecular weight organic acids. The NF-hybrid system showed higher removal efficiency of BPA than the NF-only system (95% vs. 72%) because BPA in the retentate was continuously decomposed by catalytic oxidation. Permeate flux was slightly lower, but ion rejection was higher, in the NF-hybrid system than in the NF-only system due to precipitation of Fe(III)-TsPc on the membrane surface in the NF-hybrid system.
Bibliographical noteFunding Information:
This work was supported by the Korea Science and Engineering Foundation (no. R01-2005-000-10517-0 (2006)). The authors wish to thank the SAEHAN Co. Ltd., Korea, for providing the NF membrane.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Physical and Theoretical Chemistry
- Filtration and Separation