Effect of high-frequency ultrasonication was examined on wastewater of a cheese manufacturing plant. Tests were carried out at two frequencies (500 kHz and 1 MHz) and two temperatures (22 and 40 °C). Samples were subjected to different energy densities; 7.5, 30.2, 60.5 and 121.0 J/mL at 500 kHz and 7.9, 31.7, 63.4 and 126.8 J/mL at 1 MHz to observe the creaming and recovery of lipid. These energy densities correspond to 30, 120, 240 and 480 s of sonication. Sonication was performed using a single plate transducer and reflector system at 40 W to create standing wave to coalesce and flocculate lipid globules. Recovery was higher at 40 °C after 480 s of sonication at both frequencies (77% at 500 kHz and 75% at 1 MHz). The lowest recovery of 47% was observed at 500 kHz and 22 °C at all applied energy densities. Changes in particle size and turbidity in the bottom aliquot indicated that high-frequency ultrasound caused coagulation and aggregation and settling of colloidal particles. Increase in particle size was observed to be highest at 1 MHz, 40 °C and 480 s of sonication. These results confirm that high-frequency ultrasound standing wave technology can be used to recover lipid from high-lipid dairy wastewater including that from cheese manufacturing.

中文翻译：

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高频超声波驻波在从高脂乳制品废水中回收脂质中的应用。

研究了高频超声处理对奶酪制造厂废水的影响。在两个频率（500 kHz和1 MHz）和两个温度（22和40°C）下进行测试。样品经受了不同的能量密度。在500 kHz时分别为7.5、30.2、60.5和121.0 J / mL，在1 MHz时为7.9、31.7、63.4和126.8 J / mL，以观察脂质的乳脂化和回收率。这些能量密度对应于30、120、240和480 s的超声处理。使用单板换能器和反射器系统以40 W进行超声处理，以产生驻波以凝聚和絮凝脂质小球。在两个频率下超声480 s后，在40°C下的恢复率都更高（500 kHz下为77％，1 MHz下为75％）。在所有施加的能量密度下，在500 kHz和22°C下观察到的最低回收率为47％。底部等分试样的粒径和浊度变化表明，高频超声引起胶体颗粒的凝结，聚集和沉降。在1 MHz，40°C和480 s的超声处理下，观察到最大的粒径增加。这些结果证实，高频超声驻波技术可用于从高脂乳制品废水（包括奶酪制造废水）中回收脂质。