Quantax 400 detector

The powder X-Ray diffraction (PXRD) patterns of both samples were recorded on an Empyrean PANalytical diffractometer equipped with a Cu-Kα monochromatic radiation source. The crystal morphology of AM-3 and AM-4 was analyzed using scanning electron microscopy (SEM) on a Hitachi SU-70 SEM microscope with a Bruker Quantax 400 detector operating at 20 kV.

The E. globulus bark used in this work was provided by The Navigator Company (Cacia, Portugal), directly from its debarking/crushing unit (see Figure S1, Supplementary Materials). The biosorbent was dried under room temperature and humidity conditions, and it was then cut into pieces with ca. 1 cm length (see Figure 7). No additional chemical or thermal pretreatments were applied before the sorption assays. The morphology was assessed by SEM using a Hitachi SU-70 SEM microscope with a Bruker Quantax 400 detector operating at 20 kV. The FTIR spectra of the biosorbent before and after sorption were recorded with a Bruker Tensor 27 spectrometer coupled to a horizontal attenuated total reflectance (ATR) cell using 256 scans at a resolution of 4 cm⁻¹. The samples were examined directly, and data were obtained as absorbance from a wavenumber range from 400 to 4000 cm⁻¹. The biosorbent PZC was determined according to the immersion method proposed by Fiol and Villaescusa [27 (link)] using an incubator shaker HWY-200D.