## 3 Results and Discussion
### Batch Adsorption Performance of EGS@APTES-GT
#### 3.2.2 Adsorbents Isotherms  
Adsorption isotherms are models that describe the distribution of the adsorbate species among the solid and liquid phases, and are an important methodology useful for understanding the adsorption mechanism. In this study, Langmuir, Freundlich, and Temkin isotherm models were used to describe the relationship between the adsorbed amount of arsenate and Iprodione on the hybrid EGS@&APTES-GT adsorbent (SM S3.2.2). For that purpose, the anionic pollutant As(V) and Iprodione as the neutral pollutant [50] were used in this batch adsorption study. The values of the adsorption capacity (\(q_{\text{max}}\)), model parameters, and the coefficients of determination (R\({}^{2}\)) for each used isotherm model obtained by a non-linear fitting methodology are presented in Table 1 and Figure S7. The values of the coefficient of determination for the Langmuir fitting model were 0.98 and 0.96 for arsenate and Iprodione adsorption, respectively. These results indicate the monolayer coverage of the pollutant on the surface of EGS@APTES-GT [37]. The adsorption capacity of the EGS@APTES-GT increased as the operational temperature increased. The calculated \(q_{\text{max}}\) values at 318 K were 56.11 and 114.0 mg g\({}^{-1}\) for arsenate and Iprodione, respectively. The essential feature of the Langmuir isotherm can be expressed by means of R\({}_{\text{L}}\)[51] and in this study, the values of R\({}_{\text{L}}\) calculated from Equation (S7) are shown in Table 1. The values of R\({}_{\text{L}}\) at all temperatures and for all used pollutants indicate that the adsorption processes are favorable [52]. The correlation coefficients are the best in the case of Freundlich isotherm modeling. The adsorptive results, obtained according to non-linear Freundlich model fitting, is presented in Figure S7 and Table 1. An adsorption system is generally considered as favorable for 1/n values in the range from 0.1 to 0.5 and moderately favorable for the range from 0.5 to 1.0 [53]. Considering the high fitting validity from Table 1, it indicates that EGS@APTES-GT is a good adsorbent for arsenate and Iprodione removal by forming multilayer adsorbate coverage. In general, the results from Table 1 suggest a complex adsorption mechanism achieved by the interplay of both physisorption, the main operative of Iprodione removal, and chemisorption, dominant in the complexation of arsenate species. The parameter AT (L g\({}^{-1}\)) from the Temkin isotherm model represents the bond constant perceived in the maximal binding energy. Values of B from Table 1 are related to the variation of the adsorption energy and are positive. These values indicate that the adsorption reactions are endothermic [54]. Due to the high porosity originating by expanded glass aggregates, organic molecules as fungicides, regardless of their size, diffuse easily through the material so the higher adsorbent efficiency in comparison to inorganic pollutants [55] can be elucidated. The adsorption capacities of EGS@APTES-GT for arsenate and Iprodione were compared to those from the literature (Table 2). Listed experimental conditions are based on concentrations and the pH range, temperature, and adsorbent mass-to-volume ratio. Table 2 summarizes these data and the adsorption capacities of other adsorption materials pointed out that EGS@APTES-GT, a highly porous and functionalized adsorbent material, has good adsorption properties. There are no reports of the Iprodione adsorption with adsorbent materials based on recycled glass modified with goethite.