超声破解辅助湿法测定活性污泥中总磷含量

Determination of the total phosphorus content in activated sludge by ultrasonic pretreatment assisted wet method

采用超声破解辅助湿法测定活性污泥中总磷(TP)含量,在单因素试验的基础上,以TP的含量为响应值,通过响应曲面分析考察了取样量、超声时间和超声功率3个因素之间的单独及交互作用,并对超声破解辅助湿法、微波消解法、SMT法、国标改进法4种污泥TP测定方法进行了对比.结果表明,在污泥混合液取样量为15mL,超声时间为22min、超声功率为720W条件下,超声破解辅助湿法测定污泥中TP准确性、稳定性最高.4种方法测定污泥TP结果依次为超声破解辅助湿法>微波消解法>SMT法>国标改进法,同时超声破解辅助湿法与其他3种方法之间存在较高的线性相关关系(相关系数分别为0.9997、0.9977、0.9969),拟合函数斜率分别为0.9436、0.9183、0.8295.超声破解辅助湿法测定污泥样品TP平行测定的RSD≤3.6%,加标回收率为96.5%~104.8%.超声破解辅助湿法测定活性污泥TP具有良好的可靠性、经济性、操作便捷性,超声处理本质上节省了化学药剂和提取时间.

The total phosphorus(TP)content of activated sludge was determined by an ultrasonic cracking assisted wet method.This study investigated the individual and interactive effects between three factors of sampling volume,sonication time,and sonication power,using the response surface methodology with the TP content as the response value,based on the single-factor test.Meanwhile,four sludge TP determination methods were compared,i.e.,ultrasonic cracking wet method,microwave digestion method,SMT method,and improved national standard method.The results showed that the ultrasonic cracking wet method had the highest accuracy and stability in determining the TP content of sludge under the conditions of 15mL of sludge mixture sampling volume,22min of ultrasonic time,and 720W of ultrasonic power.The results of the sludge TP determination followed the order of ultrasonic cracking wet method>microwave digestion method>SMT method>improved national standard method.There was a significant linear correlation between the ultrasonic cracking wet method and the other three methods(correlation coefficients of 0.9997,0.9977,and 0.9969,respectively)with the fitted function slope values of 0.9436,0.9183,and 0.8295,respectively.The RSDs for the determination results of TP in sludge samples by the ultrasonic cracking wet method were≤3.6%and the spiked recoveries were 96.5%~104.8%.This study demonstrates that the ultrasonic cracking wet method is of good reliability,economy,and ease of operation in determining TP.Furthermore,ultrasound can save chemicals and extraction time.