Document Type : Original Article
Department of Water, Wastewater and Environmental Engineering, Faculty of Water and Environmental Engineering, Shahid Beheshti University, Tehran, Iran
Department of Environmental Technologies, Environmental Sciences Research Institute, Shahid Beheshti University, Tehran, Iran
Department of Environmental Economics, Environmental Sciences Research Institute, Shahid Beheshti University, Tehran, Iran
Liner is one of the most important components of waste landfills, which its main function is to limit the penetration of leachate caused by the waste from landfill base. Since the cost of a lining system is a significant part of landfill’s total cost, therefore, it is necessary to design the compacted clay liner with environmental and economic considerations in the same way, which requires identification of factors affecting the construction cost of clay liner.
Materials and methods:
For this purpose, using the performance-based approach, the factors affecting the technical design and hydraulic performance of clay liners in preventing leachate leakage, four variables include of trench height, trench lifespan, land price and distance from the soil loanl, have been identified as the variables affecting the cost of clay liner construction. Using the HYDRUS one-dimensional model, the appropriate liner thickness was determined in the scenarios of 30, 60,180,360,720 and 1080 days for the trench lifespan. Then by defining design scenarios based on the effective variables, the cost of different parts is estimated.
Results and discussion:
Investigating the cost variations shows that increasing the height of the trench in different parts leads to lower costs of construction.While changes in the cost of liner construction over the lifespan of the trench first had a downward trend and then incremental pattern.The variations in total cost is affected by land cost variations and indicates the importance of land prices in assessing the overall costs of constructing the liner. Also an increase in the distance from the loan increases the cost of liner construction significantly, and if the suitable soil for lining to be located more than 100 km from the site, then the use of Geosynthetic clay liners is more cost-effective. The trench life time as a variable with less design constraint, can be considered depending on the cost of other parts.
Investigating costs in different parts of compacted clay liner construction shows the necessity of economic modeling and creation of cost functions for optimal design of compacted clay liners in every area.