生物表面活性剂在城市污泥静态强制通风好氧堆肥中的作用

采用静态强制通风好氧堆肥模式对城市剩余污泥进行堆肥降解,并研究了生物表面活性剂鼠李糖脂对堆肥过程的作用。结果表明,堆肥过程中,添加了质量分数为0.015%鼠李糖脂溶液堆制处理和空白对照堆制处理的堆温变化都明显呈现出中温期0～5 d、高温期6～12 d和降温期13～28 d 3个阶段。实验组比空白组的堆体升温快、高温期持续时间长、堆体的含水率高。鼠李糖脂的添加,使实验组的微生物数量高于空白组。添加鼠李糖脂的堆体和空白堆体的种子发芽指数(GI)在堆肥结束时分别为53.70%和50.80%,说明鼠李糖脂促进了堆肥的腐熟,但由于相对浓缩效应,堆肥产品的重金属含量略高于空白堆体。生物表面活性剂的介入促进了堆肥中木质纤维素的初步降解。研究表明,添加鼠李糖脂能够改善堆肥处理的微环境,促进有机质降解和堆肥的腐熟。

Application of biosurfactant in static forced-aeration composting of sewage sludge

The study focused on the effect of rhamnolipid biosurfactant application on static forced-aeration composting of excess activated sludge.During the process of composting,significant changes of the temperature caused by the two treatments were defined as three stages including a mesophilic period(0~5 d),a thermophilic period(6~12 d) and a maturing period(13~28 d).The warming rate and the duration of high temperature of the treatment with rahmnolipid at 0.015% as well as its moisture content was higher than that of the control.The rhamnolipid addition increased the microbial population.At the end of the composting,the GI(germination index) reached 53.70% and 50.80%,respectively,indicating that addition of rahmnolipid accelerated the decreasing of the compost rhamnolipid.However,due to the enrichment effect,the heavy metal concentration was slightly higher than that of the control one.The experiment indicated that the addition of rahmnolipid can improve the microenvironment of composting,and as a result,accelerate the composting process and improve the quality of composting products.