Enhancing Water Treatment Residuals Characterization Through MNDT-Assisted Dielectric Properties Investigation via Oven Heating

The quantity of activated sludge generated by global municipal water treatment facilities has experienced a significant increase. Improper handling of disposed water treatment residuals can lead to hazardous substances within the residuals, potentially causing secondary contamination. This research employs microwave non-destructive testing (MNDT) to quantify and analyze the dielectric properties of water treatment residuals. MNDT was chosen for its non-invasive nature, preserving the original sample composition. Operating within the X-band region, the MNDT utilizes a frequency range of 8 to 12 GHz. This study aims to assess the impact of thermal heating via an oven on water treatment residuals. The heating process incorporates two key parameters: temperature variation and duration. Identifying the optimal oven temperature holds significance in transforming sludge into viable pre-carbonized material. The mass alteration of 500 g of initial raw water treatment residuals occurs in two states-granular and powdered. Subsequently, these materials undergo MNDT testing to ascertain their relative dielectric constant. The acquired data are then compared with a recognized permittivity value for carbonized material, aligning with potential applications in activated carbon production.