Department of Chemistry, Mangosuthu University of Technology, PO Box 12363, Jacobs, 4026, South Africa.
School of Chemistry, Westville Campus, University of KwaZulu-Natal, P Bag X54001, Durban, 4000, South Africa.
J Hazard Mater. 2018 Sep 5;357:415-423. doi: 10.1016/j.jhazmat.2018.06.006. Epub 2018 Jun 2.
The study investigates the degradation of 2,4,6-tribromophenol (2,4,6-TBP) and the influence of solution pH, alkalinity, HO and O dosage. Debromination efficiency of 2,4,6-TBP was the highest in basic water (pH = 10.61). The extent of TOC removal compared favourably with the amount of substrate converted, suggesting favourable mineralization of oxygenated by-products (OBPs). Ozonation in basic water favoured the formation of toxicBrO, while in acidic water (pH = 2.27) BrO yield was lowest. In acidic water the presence of CO showed negligible effect on conversion, TOC and BrO yield compared to ozonation alone. In basic water both 2,4,6-TBP conversion and TOC removal decreased with an increase in CO, hence minimizing BrO formation. The O/HO process showed an improvement in the debromination efficiency and TOC data revealed that total mineralization of OBP's was achieved. However, only 10% HO was able to effectively decrease BrO formation. Increasing the ozone concentration from 20 to 100 ppm enhanced the conversion of 2,4,6-TBP and TOC removal. At low ozone concentrations poor mineralization of OBP's occurred, while complete mineralization was achieved at higher ozone dose. The reaction pathways for ozone degradation of 2,4,6-TBP in acidic and basic waters is proposed.
该研究考察了 2,4,6-三溴苯酚（2,4,6-TBP）的降解以及溶液 pH 值、碱度、HO 和 O 用量的影响。在碱性水中（pH=10.61），2,4,6-TBP 的脱溴效率最高。TOC 的去除程度与转化的底物量相当，表明含氧副产物（OBPs）的有利矿化。在碱性水中，臭氧化有利于有毒 BrO 的形成，而在酸性水（pH=2.27）中 BrO 的产率最低。在酸性水中，与单独臭氧化相比，CO 的存在对转化率、TOC 和 BrO 产率几乎没有影响。在碱性水中，随着 CO 的增加，2,4,6-TBP 的转化率和 TOC 的去除率均降低，从而最大限度地减少了 BrO 的形成。O/HO 工艺提高了脱溴效率，TOC 数据表明 OBP 的总矿化得以实现。然而，只有 10%的 HO 能够有效地减少 BrO 的形成。将臭氧浓度从 20 ppm 增加到 100 ppm 提高了 2,4,6-TBP 的转化率和 TOC 的去除率。在低臭氧浓度下，OBPs 的矿化作用较差，而在较高的臭氧剂量下则实现了完全矿化。提出了酸性和碱性水中臭氧降解 2,4,6-TBP 的反应途径。
