School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
PLoS One. 2012;7(7):e27571. doi: 10.1371/journal.pone.0027571. Epub 2012 Jul 19.
Landfills leachates are known to contain recalcitrant and/or non-biodegradable organic substances and biological processes are not efficient in these cases. A promising alternative to complete oxidation of biorecalcitrant leachate is the use of ultrasonic process as pre-treatment to convert initially biorecalcitrant compounds to more readily biodegradable intermediates. The objectives of this study are to investigate the effect of ultrasonic process on biodegradability improvement. After the optimization by factorial design, the ultrasonic were applied in the treatment of raw leachates using a batch wise mode. For this, different scenarios were tested with regard to power intensities of 70 and 110 W, frequencies of 30, 45 and 60 KHz, reaction times of 30, 60, 90 and 120 minutes and pH of 3, 7 and 10. For determining the effects of catalysts on sonication efficiencies, 5 mg/l of TiO(2) and ZnO have been also used. Results showed that when applied as relatively brief pre-treatment systems, the sonocatalysis processes induce several modifications of the matrix, which results in significant enhancement of its biodegradability. For this reason, the integrated chemical-biological systems proposed here represent a suitable solution for the treatment of landfill leachate samples.
垃圾填埋场渗滤液中含有难生物降解或不可生物降解的有机物质，而生物处理过程在这些情况下效率不高。超声预处理作为一种将难生物降解渗滤液完全氧化的替代方法，具有广阔的应用前景，它可以将初始的难生物降解化合物转化为更易生物降解的中间产物。本研究的目的是研究超声过程对生物降解性改善的影响。通过析因设计进行优化后，采用分批处理模式将超声波应用于原始渗滤液的处理中。为此，针对功率强度为 70 和 110 W、频率为 30、45 和 60 kHz、反应时间为 30、60、90 和 120 分钟以及 pH 值为 3、7 和 10 的不同情况进行了测试。为了确定催化剂对声催化效率的影响，还使用了 5 mg/L 的 TiO2 和 ZnO。结果表明，当作为相对短暂的预处理系统应用时，声催化过程会引起基质的多种变化，从而显著提高其生物降解性。因此，这里提出的化学-生物集成系统为处理垃圾填埋场渗滤液样品提供了一种合适的解决方案。
