Comparison of a novel enzymatic biodegradability test method with microbial degradation methods

A novel enzymatic hydrolysis test (EHT) has been evaluated as a surrogate for conventional microbial biodegradability methods, using 37 assorted organic waste samples collected from diverse sources. The results of the EHT method are compared with those obtained from two conventional tests; the 4 day aerobic DR4 and 100 day anaerobic BM100 test methods currently applied in England and Wales. The EHT is based on the enzymatic hydrolysis of cellulosic materials and can be completed in less than 24 hours. Linear regression for 37 samples against the BM100 data showed the DR4 provided a correlation coefficient of r = 0.58; the EHT method gave a correlation of r = 0.62 for the total DOC release; and r = 0.77 for the DOC released from enzymatic hydrolysis. The correlations suggest that the EHT method may be better suited to a wider range of waste types when correlating with anaerobic BM100 test results since it more closely mimics the full extent of decomposition rather than that from the readily biodegradable fraction.