Treatment of Clariflocculated Textile Industry Effluent by Modified Graphene Oxide Nanomaterial–Chitosan Composite for Removal of 2-Methylpyridine.

Raw industrial effluent was collected from a textile dyeing industry in which 2-methylpyridine (2Mp) was used as a solvent in the dyeing and rinsing bath of cotton fabric. The wastewater was characterized and found to contain a higher 2Mp concentration than the discharge limit set by USEPA (1 mg/L). High-performance liquid chromatography (HPLC) was utilized for the detection and quantification of 2Mp in the effluent. Because adsorption is a tertiary level of treatment, a pretreatment using clariflocculation (CF) was imparted to the raw effluent in order to reduce the high organic load, suspended solids, and other unknown interfering species. The CF-pretreated effluent then was subjected to both batch and column sorption using modified graphene oxide nanomaterial crosslinked with chitosan and coated onto sand (GCS) in order to evaluate its 2Mp removal efficiency. This study is a novel attempt at the removal of 2Mp from textile dyeing effluent, which was not addressed in previous studies. Carboxyl-rich graphene oxide nanomaterial was prepared using the method of prior cooling and thermal control. It was found that the 2Mp adsorption capacity of GCS was reduced by about 27.8% in the case of industrial samples compared with synthetic 2Mp samples. The suggested treatment reduced the 2Mp concentration in the industrial effluent to below the safe discharge limit of 1 mg/L. The effect of dissolved co-occurring ions on removal of 2Mp by sorption was studied, and it was that whereas the potassium and sulphate ions were most disruptive to the sorption of 2Mp, calcium ion aided the sorption process via complexation. [ABSTRACT FROM AUTHOR]