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This work aims to verify the effects of the natural structure of a residual soil on its erodibility and the potential, employing compaction, to restore the erosion resistance. It is a residual soil of gneiss that occurs in the state of Santa Catarina, Southern Brazil. Infrastructure earthworks expose this material to the action of water, which can develop severe erosive features. The erodibility evaluation was made using the MCT methodology based on infiltrability and modified loss of mass by immersion tests. These tests were conducted in undisturbed specimens at natural moisture content and in compacted specimens at optimum moisture content. Such tests were also carried out in specimens air-dried for 24, 48, and 96 hours. This soil is inherently erosive, but the natural macrostructure makes it even more susceptible to erosion. Even compaction under modified energy is not able to recover the erodibility resistance. Drying slightly reduces the soil’s erosive potential when compacted, regardless of the compaction energy, but clearly increases the erosive potential of undisturbed soil.

Hermetia illucens (Black Soldier Fly) larvae (BSFL) have great potential as new protein source for either feed or food use due to the high content of protein and fat. BSFL may be used in different forms including dried with extended shelf life. Mathematical models describing dehydration kinetics are useful to optimize BSFL drying conditions. A non-stationary 3D diffusion model, given by Fick's Law was used to describe the moisture depletion inside BSFL during drying. The numerical solution of PDE was obtained with COMSOL Multiphysics assuming simple boundary conditions. Data were obtained in a drying experiment performed with fresh larvae uniformly laid on a metallic grid in a forced air oven at 80 °C. Five randomly larvae were periodically selected and removed for moisture content determination until equilibrium moisture was reached. A qualitative good agreement between predictions and data was observed corroborating that the main physical phenomena were considered in the mathematical description. A better quantitave description is expected with the improvement of the boundary condition at larvae surface in the model and the upgrading of the three-dimensional geometry used as domain for the numerical resolution.