Le Ngoc Tuan, Julcour-Lebigue Carine, Barthe Laurie, Delmas Henri
Université de Toulouse, Laboratoire de Génie Chimique, INP-ENSIACET, 31030 Toulouse, France; University of Science, Vietnam National University, Ho Chi Minh City, Viet Nam.
Université de Toulouse, Laboratoire de Génie Chimique, INP-ENSIACET, 31030 Toulouse, France.
J Environ Manage. 2016 Jan 1;165:206-212. doi: 10.1016/j.jenvman.2015.09.015. Epub 2015 Oct 2.
This work aims at optimizing sludge pretreatment by non-isothermal sonication, varying frequency, US power (PUS) and intensity (IUS varied through probe size), as well as hydrostatic pressure and operation mode (continuous vs. sequential - or pulsed - process). Under non isothermal sonication sludge solubilization results from both ultrasound disintegration and thermal hydrolysis which are conversely depending on temperature. As found in isothermal operation: - For a given specific energy input, higher sludge disintegration is still achieved at higher PUS and lower sonication time. - US effects can be highly improved by applying a convenient pressure. - 12 kHz always performs better than 20 kHz. Nevertheless the optimum pressure depends not only on PUS and IUS, but also on temperature evolution during sonication. Under adiabatic mode, a sequential sonication using 5 min US-on at 360 W, 12 kHz, and 3.25 bar and 30 min US-off gives the best sludge disintegration, while maintaining temperature in a convenient range to prevent US damping.
这项工作旨在通过非等温超声处理优化污泥预处理，改变频率、超声功率（PUS）和强度（通过探头尺寸改变IUS），以及静水压力和操作模式（连续与顺序或脉冲过程）。在非等温超声处理下，污泥溶解是由超声破碎和热水解共同导致的，而这两种作用与温度呈相反关系。如在等温操作中所发现的： - 对于给定的比能量输入，在较高的PUS和较短的超声处理时间下仍能实现更高的污泥破碎率。 - 通过施加适当的压力可以显著提高超声效果。 - 12 kHz的效果总是优于20 kHz。然而，最佳压力不仅取决于PUS和IUS，还取决于超声处理过程中的温度变化。在绝热模式下，则使用360 W、12 kHz、3.25 bar进行5分钟超声开启和30分钟超声关闭的顺序超声处理，可实现最佳的污泥破碎效果，同时将温度保持在适宜范围内以防止超声衰减。
