Estimation on migration characteristics of leachate using analysis of hydraulic conductivity at bioreactor landfill

In bioreactor landfill, moisture content is one of the most important factors affecting the migration of leachate. The migration characteristics of leachate in the Sudokwon landfill site was estimated by examining relationships among self-loading weight of waste (waste weight load), bulk density, hydraulic conductivity and moisture content of the landfilled waste. Experimental zones in the Sudokwon landfill were divided into leachate recirculation zones (3-C and 4-C zone) and reference zone (3-D zone). The volume of the leachate recirculation was 207 m³ d^-1 for 12 months in the 3-C zone and 190 m³ d^-1 for 3 months in the 4-C zone. A logarithmic graph can describe the relationship between waste weight load and bulk density by moisture content. However, both the relationship between bulk density and hydraulic conductivity and the relationship between hydraulic conductivity and waste weight load can be expressed by an exponential graph. Through these relationships, generalised equations for hydraulic conductivity were established using moisture content and waste weight load. The hydraulic conductivity calculated from the generalised equation in the leachate recirculation zone was estimated to be 6.27 × 10^-4 cm s^-1 in the 3-C zone and 4.43 × 10^-4 cm s^-1 in the 4-C zone. The migration time of leachate in the leachate recirculation zone was estimated to be 64.2 days in the 3-C zone and 94.5 days in the 4-C zone, respectively.