The presence of trace levels of pharmaceutically active compounds (PhACs) in the aquatic environment threatens human health and the environment. Metronidazole (MNZ) is a soluble PhAC with low biodegradability, a possible human mutant and carcinogen. This study aimed the synthesis, physicochemical characterizations, and employment of porous amine-modified green-graphene (AMGG) for MNZ removal from aqueous solutions. Response-surface methodology (RSM) based on Box-Benken design (BBD) was used to assess the MNZ adsorption efficiency of AMGG as a function of pH (4–12), contact time (5–60 min), AMGG dose (0.1–1 g/L) and MNZ concentration (10–100 mg/L). From the model optimization, the highest MNZ removal was predicted at a pH of 5.9, a contact time of 27 min, an AMGG dose of 0.86 g /L, and an MNZ concentration of 100 mg /L. The experimental data were in agreement with the pseudo-second order kinetic model and the Langmuir isotherm model. The maximum adsorption capacity of AMGG for MNZ was 416.7 mg/g. The MNZ concentration at equilibrium increased about 4.8 mg/L when the solution temperature increased by 20 oC (from 30 to 50 °C), indicative of an exothermic process. AMGG showed an efficiency decrement from 84 % to 57 %, after five consecutive saturation-regeneration cycles. Moreover, AMGG showed a removal efficiency of 74 % when it was employed for real hospital wastewater treatment.
|Number of pages||10|
|Journal||Colloids and Surfaces A: Physicochemical and Engineering Aspects|
|Publication status||Published - 2021|
- Amine-modified green-graphene
- Hospital wastewater