The Compost of Sludge Mixture and Forest Reconstruction

Background/Objectives: Sewage sludge mainly depends on landfilling after gas extraction by anaerobic and aerobic fermentation. However, due to limitations of landfill, other alternatives should be considered. One candidate is a composting by mixture of consolidation soil. Methods/Statistical analysis: However, it is possible to prevent the external leaching of heavy metals and to utilize it for forest restoration project by mixing solidifying agent mainly composed of calcium component. Sewage sludge, abandoned mine, oyster, and solidifying agent were mixed to remove odor, and trees were planted there. The components of the solidifying agent and the measurement of harmful components of the mixture were tested and evaluated by the Korea Chemical Fusion Test Institute. Findings: Use in crops or fruits may cause consumer dissatisfaction, but it is expected to be safe because it reduces the loss of soil and does not interfere with the growth of trees. In the quarry or abandoned mine area, the mixture of the tailings, the sludge, the cowdung, the soil, and the solidifying agent were mixed to make the soil which can grow well. The solidifying agent had no heavy metal material, and there were lower components of heavy metal materials after mixing and solidifying. It is a method to prevent the leaching of heavy metals contained in the mixture of solidifying agents and to plant the forests to treat waste and to forestate them simultaneously. Improvements/Applications: This method used to restore the abandoned mine area that heavily used for cement production. It also provides a good way to restore the soil effectively to the quarry cut-outs and to grow the trees.