金刚石膜电极电化学氧化提高废水可生化性的研究

采用掺硼金刚石膜电极(BDD)电化学氧化的方法提高2-氯苯酚废水的可生化性,与钛基钌铱氧化物电极(DSA)进行对比,研究了该方法的机理.结果表明,BDD电极电化学氧化2.0h后,BOD5/CODCr值达到0.42,有效提高了废水的可生化性,而DSA电极电化学氧化2.0h后,BOD5/CODCr值仅为0.24.机理研究表明,由于BDD电极具有高的析氧电位,可产生大量的羟基自由基(×OH),能够使2-氯苯酚的苯环充分开环,形成草酸、顺丁烯二酸等易生化处理的中间产物,从而使可生化性提高;而DSA电极的析氧电位较低,产生羟基自由基的能力较差,不能有效地提高废水的可生化性.

Enhanced biodegradability of wastewater with electrochemical oxidation on boron-doped diamond anode

Electrochemical oxidation on boron-doped diamond (BDD) anode was used as pretreatment for 2-chlorophenol wastewater to improve its biodegradability, using DSA electrode as a comparison. And the mechanism was also discussed. Afeer 2h electrochemical oxidation of 2-chlorophenol wastewater on BDD electrode, BOD5/CODCr reached 0.42, while the value only reached 0.24 on DSA electrode. This was closely related with the properties of the electrode. BDD electrode had a high oxygen evolution potential, and many hydroxyl radicals were generated in the solution. This led to that 2-chlorophenol was fully ring-opening, forming intermediates such as oxalic and maleic acids which were easy to be biodegraded. Thus, the biodegradability of 2-chlorophenol wastewater was enhanced greatly. However, DSA electrode had lower oxygen evolution potential and poorer ability of generating of hydroxyl radicals. So the biodegradability of wastewater could not be improved effectively. Therefore, electrochemical oxidation on BDD electrode was an effective approach to improve the biodegradability of organic pollutants.