Photoremoval of Oil, DOC, DSS, Toluene and m-Xylene from a Petrochemical Industry via Cellulose Nanocomposites Derivated from Textile Wastes

In this study a nanocomposite namely cellulose nanocrystals (CNCs) was produced under laboratory conditions from textile wastes to remove the pollutants [oil, dissolved organic carbon (DOC), dissolved suspended solids (DSS), toluene and m-xylene] present in a petrochemical industry wastewater (PCI ww). With the aim of reducing environmental pollution and promoting economic circularity, textile wastes such as fibres, yarn clippings, fabric remnants from factory cuts, and new garments has been shown to be a viable material for nanocellulose extraction, its low cost, high amount in landflls. Nanocellulose extraction from textile waste was performed in two-stage process. Firstly, a purification process for the removal of non-cellulosic components is performed for cellulose fibre isolation then alkaline treatment and bleaching stages were applied. Afterwards, nanocellulose is extracted from cellulose fibrils. SEM analysis showed that CNCs presented a homogeneous structure. FTIR assays exhibited a band at 3422 cm−1 which is attributed to the hydroxyl groups and the band at 2889 cm−1 indicates the carboxylic acids. The XRD pattern of CNCs exibited two main diffraction peaks at 2θ angles of 8° and 18.9°. TGA of the samples exhibited low degrees of carboxyl functionalization. This reduced thermal stability and the degradation temperature. The DTG data for cellulose showed highest extent of carboxyl content in the CNCs samples. The effects of some operational conditions such as increasing of photoremoval time, increasing pH values, increasing pollutant concentrations (oil, DOC, DSS, toluene and m-xylene) and increasing CNCs nanocomposite concentrations on the maximum yields of PCI ww pollutants were investigated. Maximum 99.30% oil, 99.10% DOC, 99.52% DSS, 95.64% toluene, and 99.05% m-xylene removal efficiencies were observed at 100 mg/l CNC nanocomposites concentration, in PCI ww, after 150 min photoremoval time, at pH=7.0, at 1000 mg/l pollutant concentrations, and at 25oC, respectively. Nanocellulose obtained from textile wastes is seen as a sufficient and promising alternative to synthetic polymers, with the advantage of being obtained from renewable and cheap resources and also being used in the production of adequate nanocomposites.