## 3 Results and Discussion
### Characterization of Sorbents
(2017) noted that increasing the pyrolysis temperature led to an increase in both the specific surface area (SSA) and the volume of micropores in the biochar they studied. Similarly, [PERSON] et al. (2018) and other researchers have shown that the pyrolysis temperature has a significant impact on biochar characteristics and its ability to adsorb organic pollutants. Biochars produced at higher temperatures (up to 700 \({}^{\circ}\)C) exhibit high microporous volumes, aromaticity, surface oxygen-containing functional groups, and SSA, which enhance their effectiveness as adsorbents for removing various organic pollutants. Figure 1: SEM micrographs of biochar from (**A**) corn, (**B**) hemp, and (**C**) straw. \begin{table}
\begin{tabular}{l l l l l l} \hline \hline \multirow{2}{*}{**Adsorbents**} & \multicolumn{3}{c}{**Parameter**} \\ \cline{2-6}  & \multirow{2}{*}{**BET (m\({}^{2}\)g\({}^{-1}\))**} & \multicolumn{3}{c}{**Elemental Analysis**} \\ \cline{3-6}  & & **C (\%)** & **H (\%)** & **N (\%)** & **S (\%)** \\ \hline BC1 & 111 & 70.7 & 0.210 & 1.12 & 1.39 \\ \hline BC2 & 63 & 70.5 & 0.254 & 1.12 & 1.21 \\ \hline BC3 & 61 & 67.8 & 0.281 & 1.05 & 2.21 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Characterization of investigated adsorbents originating from biomass of corn (BC1), biomass of hemp (BC2), and biomass of straw (BC3). Additionally, the surface morphology observed in Figure 1 provides visual insights into the structure of the biochars, complementing the quantitative data obtained from the BET analysis and elemental composition measurements. This comprehensive characterization offers valuable information about the physicochemical properties of the biochars, which can influence their potential applications in various environmental remediation and agricultural practices. SEM images of biochars from corn, hemp, and straw showed the loss of fibrous structure (Figure 1) with an increase in the reaction temperature, resulting in the formation of a surface that is full of defects. As expected, the highest SSA was observed for biochar originating from corn (Figure 1A) because of the formation of bigger particles compared to the surface of biochars of hemp and straw (Figure 1B,C) with more fibrous surfaces. SEM provides detailed images of the physical structure, including surface morphology, pore structure, and any signs of agglomeration. For example, biochars derived from corn, hemp, and straw likely show varying levels of surface roughness under SEM. Rough surfaces with clear pore structures suggest higher available surface areas for adsorption, while smoother surfaces indicate less adsorption capacity. Additionally, if SEM reveals heterogeneous pore sizes (varying large and small pores), it correlates to mixed microporous and mesoporous structures that BET will later quantify. If particles appear highly agglomerated in the SEM images, it implies a reduction in available surface area, as aggregation limits exposure of internal pores. In the biochars, the reported BET surface areas (111 m\({}^{2}\)/g for corn, 63 m\({}^{2}\)/g for hemp, and 61 m\({}^{2}\)/g for straw) are relatively low. The pore size distribution (micropores between 0.003 and 0.001 cm\({}^{3}\)/g and mesopores around 0.014-0.011 cm\({}^{3}\)/g) further supports the hypothesis that limited pore volumes contribute to this reduction in surface area. Agglomeration observed in SEM can also lead to blocked pores, resulting in lower surface areas. Moreover, adsorption hysteresis may reflect pore blocking or ink-bottle effects, where pore geometry restricts nitrogen molecules from entering or exiting, thus reducing the calculated surface area. For microplastic characterization, Fourier transform infrared spectroscopy (FTIR, Thermo-Nicolet Nexus 670 FTIR spectrometer, Thermo Fisher Scientific, Waltham, MA, USA) was used to characterize selected commercially available MPs and BP. The chemical structure of PEg, PET, PP, and PLA was confirmed by comparing the FTIR analysis results with the Hummel Polymer Sample Library.