Optimum Mix of Modified Sludge Used in Landfill Closure Cover System Based on the Fuzzy Analytical Hierarchy Process

For determining the optimum mix of modified sludge used in landfill closure cover system, the performance experiment of modified sludge was carried out by using polyester fiber, quick lime and high early strength cement as modified materials. Three-factor four-level orthogonal method was used to design this experiment. Physical, mechanical, chemical and economic indexes were tested and cost was calculated for evaluating the performance of modified sludge. The corresponding dimensionless parameters were determined by using linear function. The evaluation index system of optimum mix of modified sludge used in landfill closure cover system was established considering physical, mechanical, chemical and economic indexes. The final weight was acquired by using the fuzzy analytic hierarchy process. The calculating equation of the comprehensive evaluation score was established. The scores under each experiment scheme were calculated based on this equation. The evaluation result indicated that 0.1 % polyester fiber, 10% quick lime and 9% high early strength cement was the optimum mix of modified sludge.