超声波对污泥中SCFAs释放影响及作用效应研究

Research on factors and mechanism of sonication to SCFAs release from WAS

以剩余污泥为研究对象,考察了超声波处理过程中超声时间及声能密度对污泥中短链脂肪酸SCFAs释放的影响及其作用效应。实验结果表明,污泥中SCFAs的释放量随超声时间和声能密度的提高而提高,但当超声能量>270 J/mg MLSS后,SCFAs释放变缓甚至下降;在相同能耗下,长超声时间、低声能密度的超声波处理条件更有利于污泥SCFAs的释放,超声时间影响更显著;污泥中释放的SCFAs以乙酸及丙酸为主。在超声波释放剩余污泥SCFAs过程中自由基效应及热效应皆不显著,机械效应起最主要作用。

Ultrasonic technology was used to treat wastewater sludge in order to investigate the influence of ultrasonic time and ultrasonic intensity to the release of short-chain fatty acids（ SCFAs） from waste activated sludge（ WAS） and the mechanism. The result showed that the amount of released SCFAs increased over ultrasonic time and ultrasonic intensity,but when the input energy was over 270 J / mg MLSS,the release of SCFAs decreased; at the same energy consumption,the situations of longer ultrasonic time and lower ultrasonic intensity resulted in more effective SCFAs release compared to that of relatively shorter ultrasonic time and higher ultrasonic intensity; acetic acid and propanoic acid are the main parts of SCFAs released from sludge. Machinery effect was most important in the release of SCFAs from WAS by sonication,free radical effect and thermal effect were not significant.