Correlations of Substrate Microorganisms and Enzyme Activities with Wastewater Purification Effects in Subsurface Infiltration System

Abstract

The number of substrate microorganisms and enzyme activities of a lab-scale subsurface infiltration system (SIS) were monitored by plate counts, MPN and colorimetric analysis. The removal rates of BOD, COD, TP, TN and ammonia-N were measured. The results showed there were significantly positive correlation (P<0.05) between numbers of bacteria, fungi in the substrate and removal rates of COD and BOD. The correlation between number of nitrifying bacteria and removal rates of ammonia-N and correlation between number of denitrifying bacteria and removal rates of TN were significant. Meanwhile, a significant correlation between phosphatase activities and removal rates of TP (r=0.9885, P<0.05) can be also found. There was significantly positive correlation between urease activities and removal rates of TN (r=0.9698, P<0.05). These conclusions give reference to future research on utilizing substrate microorganisms and enzyme activities as an evaluating wastewater purification effects in SIS.