One-dimension model for transport of organic contaminants in double-artificial composite liner under thermal osmosis

A one-dimensional model for transport of organic contaminants in a double-artificial composite liner under thermal osmosis is proposed. The model is simulated by using the COMSOL Multiphysics. The results show that the bottom concentration only increases by 4.9% even when the leachate head increases to 10 m. It means that the effects of leachate head on transport of organic contaminants in the double-artificial composite liner are negligible. The bottom concentration of the double-artificial composite liner system will increase by 31.5% when the coefficient of thermal osmosis increases to 5×10^-11 m²·K^-1·s^-1. The effects of thermal osmosis should be considered in the double-artificial composite liner design when the coefficient of thermal osmosis reaches 1×10^-11 m²·K^-1·s^-1. The length of wrinkle and the frequency of holes on the secondary liner geomembrane have significant effects on contaminant transport in the double-artificial composite liner. The bottom concentration increases by 87% when the length of wrinkle increases from10 to 100 m. In the construction of the double-artificial composite liner, the construction quality of the secondary liner geomembrane should be strictly controlled to reduce the generation of wrinkles and holes, which can effectively improve the service performance of the liner system.