Effects of low-temperature thermal desorption (LTTD) treatment on the ecological properties of soil contaminated by petroleum hydrocarbons were assessed. For this purpose, various ecological properties related to soil health and physicochemical properties of the oil-contaminated soil before and after LTTD treatment were investigated. Total petroleum hydrocarbon concentration, electrical conductivity, organic matter, and total nitrogen decreased while water-holding capacity and available P 2 O 5 increased. The soil color was also changed but textural class was not changed after LTTD. The microbial number and dehydrogenase activity increased following LTTD, but there was no significant difference in the β-glucosidase and acid phosphatase activities. Seed germination succeeded after LTTD, but the germination rate was still lower than that in noncontaminated soil as the growth of plants and earthworms was. The results showed that overall soil health related to biological productivity and environmental functions was improved after LTTD and suggested that LTTD could be a better alternative to other harsh remediation methods. However, ecological indicators still show differences to the adjacent non-contaminated level. Therefore, to ensure safe soil reuse, the change in eco-physiochemical properties as well as contaminant removal efficiency during the remediation process should be considered.

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respectively. The calculated residence time was 4hr 32minutes at F1, 11hr 21minutes at F2, and 9hr 50minutes at F3, respectively. It was calculated same distance of 4 km away from effluent pipes. Although direct relation between Kudoa and marine environment could not define well based on this study result, the more studies on marine environmental stressors for olive flounder are required to conduct as a reliable method including socio-economic group and environmental group.

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Busan Development Institute AbstractChanges of soil properties due to sedimentation and erosion in the river estuary may lead changes in environmental factors that affect plant growth and distribution, Then habitats in the river estuary that provide various ecological functions can also be influenced. Topsoil samples were analyzed in order to understand the soil properties of important barrier islands and habitat types in the Nakdong river estuary. The samples were obtained from Phragmites communis and Scirpus planiculmis habitats, the tidal flats in the southern area of Eulsukdo, and in Mangeummerydeung, Baekhapdeung, and Doyodeung. Analyses results showed that bulk density, pH, organic matter content and total nitrogen concentration which were directly or indirectly affected by vegetation showed significant difference (p<0.05) with habitat types but no differences in water content and oxidation reduction potential which could be affected by soil texture and showed significant difference among barrier islands. Results suggested that soil properties on barrier islands in the Nakdong river estuary were influenced first by geomorphic changes due to sedimentation and erosion, and then by the presence or type of vegetation. A range of physical and chemical properties were analyzed; soil water content and bulk density (physical properties), and organic content and pH (chemical properties) were correlated with seven other soil properties, at a level of significance higher than 90%. These aspects played an important role in determining overall soil properties in the studied area.

Since the use of the remediated soil is undetermined, the quality of the soil should be appropriately evaluated according to its future use. In this study, we developed a soil quality assessment method that can be applied to soils after the remediation process. Soil quality was assessed based on soils that require productivity for use in agricultural fields and landscaping in uncontaminated, contaminated, and remediated cases using soil washing, landfarming, and thermal desorption. The results showed that the quality of soil washing treated deteriorated the most compared to landfarming and thermal desorption-treated soil, assessed based on the case of use as field soil. In the case of thermal desorption, the range of reduction was smaller than that of soil washing, but soil quality decreased slightly after remediation. However, in the case of landfarming, there was no change in soil quality after remediation. The soil quality indices calculated for landscaping also decreased the most in the soil washing because organic matter and pH decreased during the process. In the case of thermal desorption and landfarming, all the soil quality decreased due to contamination, but it increased slightly after remediation. The two indices applied in this study, SQIT and SQIA, showed similar trends, suggesting that both can be used for soil quality evaluation. Further research is needed on how much the soil quality evaluation results presented in this study can reflect the various services the soil ecosystem provides, that is, the actual soil functions in these soils.