Nitrogen‐Doped Graphene Nanosheets for Sustainable Removal of Pharmaceutical Contaminants from Water: Kinetics and ANFIS Modeling

Abstract

In this work, nitrogen‐doped graphene nanosheets (NGS) were synthesized to remove diclofenac sodium (DFS) from water. The NGS exhibited 99.8 % removal efficiency, adsorption capacity of 278 mg g−1 for DFS within 30 min, and excellent reusability up to 5 cycles of adsorption. The experimental data fit well with pseudo‐second order kinetic model and Langmuir isotherm model. X‐ray photoelectron spectroscopy (XPS) and FTIR studies revealed that the carboxylic group, triazine group, graphitic‐N, and pyridinic‐N groups were involved in the adsorption of DFS. The adaptive neuro‐fuzzy inference system (ANFIS) was modeled for accurate prediction of optimizing parameters for the maximum adsorptive removal (%) of DFS by NGS. A subsequent cytotoxicity assay of NGS on a green alga Chlamydomonas sp. signified non‐toxic nature. This study suggests NGS to be a promising economic adsorbent for water remediation in resource‐poor environments to fulfill “UN‐Sustainable Development Goal‐ 6”.