# Retention of the Antibiotic Cofruoxime onto Agricultural and Forest Soils
## 3 Results and Discussion
### Adsorption of CFX and Modeling
#### 3.2.2 Fitting to Adsorption Models
\begin{table}
\begin{tabular}{c c c c c c c c c c c c c c} \hline \hline  & \multicolumn{4}{c}{**[PERSON]**} & \multicolumn{4}{c}{**[PERSON]**} & \multicolumn{4}{c}{**Linear Model**} \\ \hline
**Soil** & \(K_{F}\) & **Error** & \(n\) & **Error** & **R\({}^{2}\)** & \(K_{L}\)** & **Error** & \(q_{m}\) & **Error** & **R\({}^{2}\)** & \(K_{d}\)** & **Error** & **R\({}^{2}\)** \\ \hline M1 & 478.866 & 152.237 & 1.575 & 0.29 & 0.893 & - & - & - & - & - & 247.337 & 29.375 & 0.797 \\ M2 & 5.133 & 0.958 & 0.881 & 0.07 & 0.988 & 0.013 & 0.008 & 341.167 & 174.072 & 0.989 & 3.699 & 0.122 & 0.983 \\ M3 & 22.027 & 11.843 & 0.41 & 0.23 & 0.57 & - & - & - & - & - & 4.735 & 1.169 & 0.328 \\ M4 & 3.234 & 1.002 & 0.983 & 0.11 & 0.979 & - & - & - & - & - & 3.084 & 0.113 & 0.978 \\ M5 & 470.333 & 140.326 & 1.655 & 0.3 & 0.917 & - & - & - & - & - & 233.145 & 26.194 & 0.816 \\ M6 & 32.85 & 8.286 & 1.013 & 0.25 & 0.894 & - & - & - & - & - & 33.257 & 2.798 & 0.894 \\ \hline CM & - & - & - & - & - & - & - & - & - & - & - & - & - \\ VO1 & 36.079 & 9.37 & 0.782 & 0.21 & 0.808 & - & - & - & - & - & 27.873 & 3.461 & 0.779 \\ VO2 & 40.898 & 10.846 & 0.83 & 0.28 & 0.746 & - & - & - & - & - & 35.283 & 4.958 & 0.728 \\ VO3 & 32.17 & 13.084 & 0.855 & 0.35 & 0.603 & - & - & - & - & - & 27.53 & 4.932 & 0.593 \\ VO4 & 42.584 & 6.548 & 1.378 & 0.26 & 0.943 & - & - & - & - & - & 51.391 & 3.805 & 0.917 \\ VO5 & 21.681 & 4.085 & 0.685 & 0.1 & 0.948 & 0.113 & 0.037 & 193.418 & 37.659 & 0.957 & 11.48 & 1.085 & 0.863 \\ \hline VP1 & 228.797 & 25.578 & 1.589 & 0.18 & 0.971 & - & - & - & - & - & 157.328 & 13.55 & 0.888 \\ VP2 & 327.646 & 63.461 & 1.54 & 0.23 & 0.941 & - & - & - & - & - & 201.923 & 19.545 & 0.861 \\ VP3 & 10.877 & 3.319 & 0.458 & 0.1 & 0.895 & 0.15 & 0.095 & 58.473 & 11.744 & 0.876 & 2.018 & 0.266 & 0.693 \\ VP4 & 20.2 & 5.829 & 0.944 & 0.19 & 0.947 & - & - & - & - & - & 18.56 & 1.088 & 0.947 \\ VP5 & 10.842 & 3.289 & 0.459 & 0.1 & 0.896 & 0.15 & 0.094 & 58.46 & 11.649 & 0.878 & 2.017 & 0.265 & 0.696 \\ VPR & 207.294 & 19.519 & 1.451 & 0.15 & 0.975 & - & - & - & - & - & 157.181 & 11.182 & 0.923 \\ VPT & 164.232 & 5.17 & 1.099 & 0.05 & 0.996 & - & - & - & - & - & - & 156.031 & 3.176 & 0.993 \\ \hline CV & - & - & - & - & - & - & - & - & - & - & - & - & - \\ FP & 21.07 & 3.307 & 0.978 & 0.11 & 0.971 & - & - & - & - & - & 20.43 & 0.876 & 0.971 \\ FE & 24.905 & 2.618 & 1.323 & 0.1 & 0.986 & - & - & - & - & - & 33.435 & 1.836 & 0.954 \\ FC & 20.149 & 3.368 & 1.251 & 0.14 & 0.971 & - & - & - & - & 26.738 & 1.548 & 0.949 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Fitting of adsorption results to the parameters of the Freundlich, Langmuir, and Linear models. \(K_{F}\) (L\({}^{n}\)umol\({}^{1-n}\)kg\({}^{-1}\)); \(n\) (dimensionless); \(K_{L}\) (L μmol\({}^{1}\)); \(q_{m}\) (μmol kg\({}^{-1}\)); \(K_{d}\) (L kg\({}^{-1}\)). -: error values too high for fitting. Regarding the Freundlich model, to consider the higher the values of the \(K_{F}\) parameter, the greater the adsorption capacity of the adsorbent [34]. In the present study, \(K_{F}\) values also show high variability in corn soils (3.23-478.86 L\({}^{\mathrm{n}}\)\(\mathrm{\SIUnitSymbolMicro mol^{1-n}}\) kg\({}^{-1}\)) and VP vineyards (0.84-327.64 L\({}^{\mathrm{n}}\)\(\mathrm{\SIUnitSymbolMicro mol^{1-n}}\) kg\({}^{-1}\)), with lower oscillation for vineyard soils on schist and slate and for forest soils (21.6-42.58 and 20.14-24.90 L\({}^{\mathrm{n}}\)\(\mathrm{\SIUnitSymbolMicro mol^{1-n}}\) kg\({}^{-1}\), respectively). Considering the whole set of soils used in this work, \(K_{F}\) showed a positive and significant correlation (\(p<0.05\)) with the same soil parameters as \(K_{d}\), specifically with pH in water (r = 0.56; R\({}^{2}\) = 0.31), pH and in KCl (r = 0.56; R\({}^{2}\) = 0.31), concentrations of exchangeable Ca (r = 0.71; R\({}^{2}\) = 0.50), exchangeable Mg (r = 0.45; R\({}^{2}\) = 0.20), and with eCEC (r = 0.49; R\({}^{2}\) = 0.24). [PERSON] et al.