Chu Li-Bing, Yan Sang-Tian, Xing Xin-Hui, Yu An-Feng, Sun Xu-Lin, Jurcik Benjamin
Department of Chemical Engineering, Tsinghua University, Beijing 100084, China.
Chemosphere. 2008 May;72(2):205-12. doi: 10.1016/j.chemosphere.2008.01.054. Epub 2008 Mar 6.
A microbubble ozonation process for enhancing sludge solubilization was proposed and its performance was evaluated in comparison to a conventional ozone bubble contactor. Microbubbles are defined as bubbles with diameters less than several tens of micrometers. Previous studies have demonstrated that microbubbles could accelerate the formation of hydroxyl radicals and hence improve the ozonation of dyestuff wastewater. The results of this study showed that microbubble ozonation was effective in increasing ozone utilization and improving sludge solubilization. For a contact time of 80 min, an ozone utilization efficiency of more than 99% was obtained using the microbubble system, while it gradually decreased from 94% to 72% for the bubble contactor. The rate of microbial inactivation was obviously faster in the microbubble system. At an ozone dose of 0.02g O(3)g(-1) TSS, about 80% of microorganisms were inactivated in the microbubble system, compared with about 50% inactivation for the bubble contactor. Compared to the bubble contactor, more than two times of COD and total nitrogen, and eight times of total phosphorus content were released from the sludge into the supernatant by using the microbubble system at the same ozone dosage. The application of microbubble technology in ozonation processes may provide an effective and low cost approach for sludge reduction.
提出了一种用于强化污泥溶解的微气泡臭氧化工艺，并将其性能与传统的臭氧气泡接触器进行了比较。微气泡定义为直径小于几十微米的气泡。先前的研究表明，微气泡可以加速羟基自由基的形成，从而改善染料废水的臭氧化。本研究结果表明，微气泡臭氧化在提高臭氧利用率和改善污泥溶解方面是有效的。对于80分钟的接触时间，使用微气泡系统获得了超过99%的臭氧利用效率，而对于气泡接触器，其臭氧利用效率从94%逐渐降低到72%。微气泡系统中微生物失活速率明显更快。在臭氧剂量为0.02g O₃/g(-1) TSS时，微气泡系统中约80%的微生物失活，而气泡接触器的失活率约为50%。与气泡接触器相比，在相同臭氧剂量下，使用微气泡系统时，从污泥释放到上清液中的化学需氧量和总氮增加了两倍多，总磷含量增加了八倍。微气泡技术在臭氧化工艺中的应用可能为污泥减量提供一种有效且低成本的方法。
