[Application of biosurfactant in composting of agricultural waste]

The biosurfactant of rhamonolipid (Rh) obtained from Pseudomonas aeruginosa was used in co-composting of rice straw and wheat bran, the efficiency of the promoter was studied under temperature control during the first stage of composting. Composting was done in an aerobic static bed of composting during which moisture content of mixture materials was controlled between 60% 70%, and the control of aeration adopted the timer by turns of 0.18m3/h for 20 minutes and pause for 40 minutes. Changes were studied including pH, organic matter, dissolved organic carbon (DOC), the biomass of microorganism, hemicellulase activity, carboxymethyl cellulose enzyme (CMCase) activity, hemi-cellulose and cellulose contents. The experimental results show that the degradation rate of organic matter is 13.4% higher than that of the control, and the average of DOC is improved by 2.2g/kg. The degradation contents of hemi-cellulose and cellulose are increased by 5.7%, 10.7% compared with the control. This indicate that the addition of Rh can improve microenvironment, strengthen polymers hydration, accelerate the co-composting process and improve the quality of composting production.