## 1 Introduction
Yet, the adsorption capacity of the modified sepiolite (Langmuir isotherm maximum uptake, \(Q_{m}\) = 5.62 mg/g at \(T\) =303 K and \(R^{2}\)= 0.9470) was substantially lower than most other adsorbents reported in the literature. Despite its poor adsorption capacity, the adsorption kinetics were relatively faster (equilibrium time < 30 min), when compared to other adsorbents reported in the literature. Adsorption is a surface-based rate process that causes an increase in the adsorbate concentration at the adsorbent surface, owing to the surface forces arising from the adsorbent-adsorbate interaction. In the present, nitroimidazole-adsorbent interaction is mainly attributed to the cation exchange and surface \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Nitroimidazole** & \begin{tabular}{c} **Molecular** \\ **Formula** \\ \end{tabular} & \begin{tabular}{c} **Molecular Weight** \\ **(g-mol\({}^{-1}\))** \\ \end{tabular} & \
\begin{tabular}{c} **pKa** \\ \end{tabular} &
\begin{tabular}{c} **Melting Point** \\ **(\({}^{\circ}\)C)** \\ \end{tabular} \\ \hline DMZ & C\({}_{5}\)H\({}_{7}\)N\({}_{3}\)O\({}_{2}\) & 141.13 & 2.81 & 138–141 \\ MNZ & C\({}_{6}\)H\({}_{9}\)N\({}_{3}\)O\({}_{3}\) & 171.15 & 2.58 & 159–163 \\ RNZ & C\({}_{6}\)H\({}_{8}\)N\({}_{4}\)O\({}_{4}\) & 200.15 & 1.32 & 168–169 \\ TNZ & C\({}_{8}\)H\({}_{13}\)N\({}_{3}\)O\({}_{4}\)S & 247.27 & 2.30 & 118–120 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Physicochemical properties of nitroimidazole antibiotics, DMZ: Dimetridazole; MNZ: Metronidazolezole; RNZ: Roniazole; TNZ: Tinidazole. complexation reactions (H-bonding and other polar interactions) between multifunctional antibiotic molecules [23]. Clearly, most researchers have focused on improving the uptake capacity of adsorbents for the removal of contaminants. For the development of an efficient and cost-effective adsorptive separation technology, however, both the adsorption capacity and the adsorption rate are equally important. In fact, adsorbents with higher adsorption and desorption rates are a prerequisite for the economy of any large-scale water-treatment process, where multiple cycles based on the adsorbent regeneration are employed. In the present work, we therefore report the preparation and characterization of a novel adsorbent that possesses both a high removal capacity, and a high uptake rate, for nitroimidazoles. To this end, we consider silicon carbide (SiC), which is a non-oxide ceramic with a high melting point, high hardness, high wear resistance, low thermal expansion coefficient, and good chemical resistance [23; 24; 25]. These properties make SiC useful for numerous applications, such as polishing paste, grinding, wear-resistant, and high-temperature structural materials, catalyst supports, filters for molten metal or hot gases, and reinforcement in the preparation of composites [23; 26; 27; 28; 29]. These properties of SiC are equally important for its application as a granular medium for the adsorptive removal of antibiotics, based on fixed/fluidized bed processing of the contaminated water with multiple regeneration cycles of the adsorbent. In the following, we first describe the synthesis of SiC nanoparticles via sol-gel and microwave radiation. Its rigorous characterization is then reported. The efficacy of the SiC nanoparticles, thus prepared, is investigated for the removal of four different antibiotics, i.e., DMZ, MNZ, RNZ, and TNZ, from aqueous solutions. The influence of solution pH and temperature are examined on the antibiotic uptake efficiency of the adsorbent. Both the experimental equilibrium and kinetic data were processed in conjunction with well-known theoretical models, in order to examine their capability to accurately describe the experimental data. Finally, the removal efficacy of the present adsorbent is compared with previously reported adsorbents in the literature.