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

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.