Sampling optimization for solid waste: variability assessment through replication experiment

The work is focused on the sampling optimization of solid waste, in particular the sampling of plasmix, which is the undersieve <50mm sorted out at the initial treatment unit of two plastic selection plants placed in Northern Italy. The Gy's Theory of Sampling is followed and the European standards are respected. An accurate laboratory activity allowed to define the mass of an increment and the sample mass, with the help of the shape factor. Sampling activities are defined by a specific sampling plan, using an appropriate instrument and following a random approach in the increment collection. The efficiency of the sampling activities is evaluated by the experimental estimation of total variance contributions, generated by the sampling phase and sample analysis phase. This estimation is performed by a replication experiment, making two replicates of sampling by four different sampling crews on two lots produced by the plant in different periods. The data collected will be analyzed and the variability assessment will be determined.