This study characterized the dissolved organic matter (DOM) and byproducts generated after the exposure of activated sludge to ozone and NaClO in ceramic MBR. It was found that NaClO triggered more significant release of DOM than ozone. Proteins with the molecular weight greater than 20 kDa and humic acid like-substances (HAL) were the principle components of DOM generated by NaClO, while ozone was found to effectively degrade larger biopolymers to low molecular weight substances. The results showed that more than 80% of DOM generated by NaClO and ozone could pass through the 0.2-μm ceramic membrane. Furthermore, total organic chlorine (TOCl) was determined to be the principal compound of halogenated byproducts in both cases, while the generation of TOCl by NaClO was much more significant than that by ozone. Only a small fraction of TOCl was removed by the 0.2-μm ceramic membrane. More importantly, the toxic bioassays further revealed that the supernatant of sludge suspension and permeate in the MBR with NaClO cleaning exhibited higher developmental toxicity to the polychaete embryos than those by ozone. The Results clearly showed that on-line chemical cleaning with ozone should be a more eco-friendly and safer approach for sustaining long-term membrane permeability in ceramic MBR.

这项研究表征了活性污泥暴露于陶瓷MBR中的臭氧和NaClO后产生的溶解有机物（DOM）和副产物。据发现，NaClO引发的DOM释放量比臭氧释放量大得多。分子量大于20 kDa的蛋白质和腐殖酸类物质（HAL）是NaClO生成的DOM的主要成分，而发现臭氧可将较大的生物聚合物有效降解为低分子量物质。结果表明，NaClO和臭氧产生的DOM中有80％以上可以通过0.2μm的陶瓷膜。此外，在这两种情况下，总有机氯（TOCl）被确定为卤代副产物的主要化合物，而NaClO产生的TOCl比臭氧产生的重要得多。0.2μm的陶瓷膜仅去除了少量的TOCl。更重要的是，毒性生物测定还表明，用NaClO清洗的MBR中的污泥悬浮液和渗透物的上清液，对多毛cha胚胎的发育毒性高于臭氧。结果清楚地表明，使用臭氧在线化学清洗应该是一种更环保，更安全的方法，以维持陶瓷MBR的长期膜渗透性。