Université de Rennes 1, Ecole Nationale de chimie de Rennes, CNRS, UMR 6226, 11 allée de Beaulieu CS 50837, 35708, Rennes, Cedex 7, France.
Environ Sci Pollut Res Int. 2014;21(14):8534-42. doi: 10.1007/s11356-014-2771-5. Epub 2014 Apr 6.
The feasibility of an electro-Fenton process to treat tylosin (TYL), a non-biodegradable antibiotic, was examined in a discontinuous electrochemical cell with divided cathodic and anodic compartments. Only 15 min electrolysis was needed for total tylosin degradation using a carbon felt cathode and a platinum anode; while 6 h electrolysis was needed to achieve high oxidation and mineralization yields, 96 and 88 % respectively. Biodegradability improvement was shown since BOD₅/COD increased from 0 initially to 0.6 after 6 h electrolysis (for 100 mg L(-1) initial TYL). With the aim of combining electro-Fenton with a biological treatment, an oxidation time in the range 2 to 4 h has been however considered. Results of AOS (average oxidation state) and COD/TOC suggested that the pretreatment could be stopped after 2 h rather than 4 h; while in the same time, the increase of biodegradability between 2 and 4 h suggested that this latter duration seemed more appropriate. In order to conclude, biological cultures have been therefore carried out for various electrolysis times. TYL solutions electrolyzed during 2 and 4 h were then treated with activated sludge during 25 days, showing 57 and 67% total organic carbon (TOC) removal, respectively, namely 77 and 88% overall TOC removal if both processes were considered. Activated sludge cultures appeared, therefore, in agreement with the assessment made from the analysis of physico-chemical parameters (AOS and COD/TOC), since the gain in terms of mineralization expected from increasing electrolysis duration appeared too low to balance the additional energy consumption.
采用分隔式阴极和阳极的不连续电化学池,考察了电芬顿工艺处理难生物降解抗生素泰乐菌素(TYL)的可行性。使用碳纤维毡阴极和铂阳极,仅需 15 min 电解即可完全降解 TYL;而要达到高氧化和矿化产率,分别需要 6 h 电解,产率分别为 96%和 88%。由于 BOD₅/COD 从初始的 0 增加到 6 h 电解后的 0.6(初始 TYL 浓度为 100 mg/L),表明可生化性得到提高。为了将电芬顿与生物处理相结合,考虑了 2-4 h 的氧化时间。AOS(平均氧化态)和 COD/TOC 的结果表明,预处理可以在 2 h 而不是 4 h 后停止;而在相同的时间内,2-4 h 之间可生化性的增加表明后者的时间似乎更为合适。为了得出结论,对不同电解时间进行了生物培养。然后,将电解 2 h 和 4 h 的 TYL 溶液用活性污泥处理 25 天,分别去除了 57%和 67%的总有机碳(TOC),如果考虑这两个过程,则总 TOC 去除率分别为 77%和 88%。因此,活性污泥培养与从物理化学参数(AOS 和 COD/TOC)分析得出的评估结果一致,因为从增加电解时间获得的矿化收益似乎太低,无法平衡额外的能源消耗。