酸改性颗粒污泥炭催化降解左氧氟沙星机制

以厌氧颗粒污泥制备了颗粒污泥炭，并用酸进行改性，研究其在异相类芬顿体系中降解左氧氟沙星（LEVO）效能.无机酸改性颗粒污泥炭（GSC-H₃PO₄、GSC-H₂SO₄和GSC-HCl）和未改性颗粒污泥炭（GSC-0）的吸附作用均低于5%，而颗粒污泥（GS）和草酸改性颗粒污泥炭（GSC-H₂C₂O₄）的吸附去除率约为20%.待吸附平衡后，进行异相类芬顿反应，催化剂对LEVO和总有机碳（TOC）的去除率顺序为：GSC-H₃PO₄ > GSC-H₂SO₄ > GSC-HCl > GSC-H₂C₂O₄，远高于GSC-0、GS和未加催化剂的反应.GSC-H₃PO₄表面铁含量高达12.73%，能催化产生更多的·OH，有利于有机污染物的降解.GSC-H₃PO₄对LEVO和TOC的去除率分别高达98.5%和51.9%，重复使用5次后，催化剂上铁的溶出率低于0.8%，仍保持较高的催化效率.通过三维荧光光谱分析和中间产物检测，提出一种LEVO降解途径.此外，GSC-H₃PO₄催化剂还能有效处理医院废水.

Mechanism of the catalytic degradation of levofloxacin by acid-modified granular sludge carbons

Granular sludge carbon was prepared from anaerobic granular sludge. After modified with acids, the granular sludge carbons were used for the degradation of levofloxacin (LEVO) in heterogeneous Fenton-like system. The adsorption rates were all lower than 5% when using granular sludge carbons modified with inorganic acids (i.e. GSC-H₃PO₄, GSC-H₂SO₄, and GSC-HCl) and the pristine one (i.e. GSC-0), whereas the adsorption rates were approximately 20% with granular sludge (GS) and granular sludge carbon modified with oxalic acid (GSC-H₂C₂O₄). The heterogeneous Fenton-like reaction wasn't conducted until the adsorption equilibrium was achieved. The removal efficiencies of LEVO and total organic carbon (TOC) followed the order:GSC-H₃PO₄ > GSC-H₂SO₄ > GSC-HCl > GSC-H₂C₂O₄, which were all higher than those reactions with GSC-0, GS and no catalyst. The iron content on the surface of GSC-H₃PO₄ was up to 12.73%, inducing the production of more ·OH, and thus promoted the degradation of organic pollutants. The LEVO and TOC removal rates with GSC-H₃PO₄ reached 98.5% and 51.9%, respectively. After GSC-H₃PO₄ was used for five times repeatedly, the iron leaching rate was below 0.8%, and the catalyststill maintained a high catalytic efficiency. A degradation pathway of LEVO was proposed based on the results of three-dimensional fluorescence spectroscopy and intermediates identification. In addition, GSC-H₃PO₄ was effective in the treatment of hospital wastewater.