ISSN: 1659-2751

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Efficiency of Effective Microorganisms (EM) for the Stabilization of Septage for Reuse in Agriculture

Abstract

The present project is an initial investigation into an adequate treatment for septage produced at EARTHUniversitythat would allow for its subsequent use on agricultural lands. The goal of the treatment is to stabilize the biological and physical characteristics of the septage, thus transforming it into a usable material. This stabilization ensures the elimination of pathogenic agents and decomposition products that emanate offensive odors. To accomplish this goal, the product Effective Microorganisms (EM) was used. This product is a mixture of beneficial microorganisms that create a negative environment for the pathogenic and odor producing agents. In the investigation, duplicate samples of septage (1 m3) were incubated anaerobically for one month. There were two treatments, 0% and 10% (v/v) EM. Sub-samples of the septage were collected at zero, two and four weeks of incubation and were analyzed for biological, chemical, and physical characteristics. A difference between the two treatments was observed after two weeks of incubation. When 10 % EM was applied, there was an almost complete reduction in fecal and total coliforms as compared to the 0 % EM treatment, and the odor emanating from the septage treated with 10% EM changed from a very strong putrefied odor to a strong fermented odor. Other changes with this treatment included reductions in biochemical oxygen demand (BOD5) and nitrate concentration, as well as lower pH (acidification), as compared to the 0 % EM treatment. These results show the effectiveness of EM in the stabilization of septage. It is recommended that this line of investigation continue to determine the exact concentration EM required for the stabilization, and the effect of application of the digested septage to agricultural lands.

Key words: Agriculture, fecal coliforms, stabilization, septage, Effective Microorganisms (EM), biological treatment.

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