Effect of Sewage Effluent on Microbial Activities and Coliform Populations of Pahokee Muck1
- Robert L. Tate and
- Richard E. Terry2
To determine the effect of amendment with sewage effluent on microbiological properties of organic soils, dehydrogenase, carbon metabolism by the microbial community, and coliform survival were examined in field plots of Pahokee muck (a Lithic Medisaprist). Test plots were amended at weekly intervals with sewage effluent at a rate of 5 cm/week. Control plots received water at comparable rates or were unamended. Dehydrogenase activities were increased approximately twofold in the sewage and water amended soils over levels detected in the unamended soil. No significant variation, in bacterial populations was detected due to any treatment. Carbon metabolism in sewage and water amended soils was nearly equivalent and both activities were generally greater than those measured in unamended soils. These data indicate that the increased microbial activity in sewage-amended plots resulted from augmented soil moisture and not the added nutrients of the sewage.
Coliform (fecal and total) populations in the soil declined approximately 90% during the first 2 days following the addition of sewage effluent. Coliforms were detected to a 95-cm depth in soil columns receiving sewage effluent for 22 weeks. These studies indicate that survival of the coliforms is limited in Pahokee muck, but that viable coliforms penetrated throughout the soil profile.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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