| Summary: | 碩士 === 國立中興大學 === 環境工程學系 === 92 === Biosolids can be used as the fertilizer and soil amendment to improve soil quality and soil microbial activity. However, limited researches of the application of biosolids on the bioremediation of contaminated soil can be found in literatures. This study focuses on exploring the effect of adding biosolids on the bioremediation system of organic-contaminated soils. It aims at utilizing the beneficial use of biosolids to supply more competent microorganisms, organic matters and nutrients to enhance the biodegradation of organic contaminants in the considered soil system.
The target compound of toluene or naphthalene was used in this study. A series of soil batch tests were conducted to determine the degradation rate of the contaminant in the soil and the mixture of soil and biosolid (MSB). The MSB were prepared with different soil to biosolid ratios, which were 1:0.2, 1:0.5 and 1:1. Comparing the result of the soil control test, the biodegraded removals of toluene or naphthalene for the three MSB tests with ratios of 1:0.2, 1:0.5 and 1:1 were significantly enhanced by 49%, 81% and 75%, respectively. However, the biodegradation rates for both contaminants were not increased monotonically with the increasing amount of added biosolids.
The contaminated soils applied with different soil to biosolid mixing ratio were also monitored by a respirometer to measure the oxygen uptake caused by the biological oxidation in the soil system. The oxygen uptake (Ou) data of the testing results were transformed to be oxygen uptake rate respirograms (OUR vs. Ou), and these respirogram were analyzed with a revised two-phase model. It can be concluded that the increased oxygen uptake contributed by biosolids was mostly from the decay of biomass inherited in biosolids.
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