Liang Liping, Cheng Liubiao, Zhang Yuting, Wang Qian, Wu Qian, Xue Yuanyuan, Meng Xu
School of Civil Engineering, Shaoxing University Shaoxing 312000 P. R. China
College of Life Science, Shaoxing University Shaoxing 312000 P. R. China.
RSC Adv. 2020 Aug 3;10(48):28509-28515. doi: 10.1039/d0ra03125a.
Based on the Fe/HO heterogeneous Fenton system, the degradation of rhodamine B (RhB, an organic dye pollutant) was researched in this paper. The effects of initial pH value, concentration of HO, dosage of zero-valent iron (ZVI), and initial RhB concentration on RhB degradation by Fe/HO were studied. The results showed that when the initial pH = 4, dosage of ZVI was 9 mM, and concentrations of HO and RhB were 8 mM and 0.1 mM, respectively, the color of RhB could be completely faded within 30 min, and the total organic carbon (TOC) removal percentage was about 63% after 120 min. The dissolved oxygen (DO) content and oxidation-reduction potential (ORP) were monitored during the reaction. Quenching experiments with methanol confirmed that the degradation of the dye was mainly due to oxidation by the ˙OH radical. Besides, the results from UV-Vis spectroscopy showed that the degradation of RhB was mainly due to the destruction of the conjugated oxygen hetero-anthracene in the RhB molecule. The solid-phase characterization of the ZVI samples after reaction confirmed that the original regular and slippery ZVI samples finally were corroded into rough and irregular lepidocrocite and magnetite. Two possible competitive reaction pathways for the degradation of RhB by Fe/HO were proposed by GC-MS analysis, which were attributed to the dissociation of ethyl radicals and the degradation of chromophore radicals.
基于铁/过氧化氢非均相芬顿体系，本文研究了罗丹明B（RhB，一种有机染料污染物）的降解情况。研究了初始pH值、过氧化氢浓度、零价铁（ZVI）用量和初始RhB浓度对铁/过氧化氢降解RhB的影响。结果表明，当初始pH = 4、ZVI用量为9 mM、过氧化氢和RhB浓度分别为8 mM和0.1 mM时，RhB的颜色可在30分钟内完全褪去，120分钟后总有机碳（TOC）去除率约为63%。反应过程中监测了溶解氧（DO）含量和氧化还原电位（ORP）。甲醇猝灭实验证实染料的降解主要是由于羟基自由基的氧化作用。此外，紫外可见光谱结果表明RhB的降解主要是由于RhB分子中共轭氧杂蒽的破坏。反应后ZVI样品的固相表征证实，原来规则光滑的ZVI样品最终被腐蚀成粗糙不规则的纤铁矿和磁铁矿。通过气相色谱-质谱分析提出了铁/过氧化氢降解RhB的两种可能的竞争反应途径，这归因于乙基自由基的解离和发色团自由基的降解。
