Abstract
Serious environmental deterioration caused by synthetic waste plastics, and the pollution of freshwater resources are the most alarming and marked challenges of the 21st century. Therefore, immense scientific efforts are being made towards the management of waste plastics and treatment of polluted water. The current study reports on the utilization of waste polyethylene terephthalate (wPET) and waste polystyrene (wPS) for fabrication of activated carbon (AC) and its application for the removal of hazardous polycyclic aromatic hydrocarbons (PAHs) pollutants from water. AC was prepared from wPET and wPS by carbonization under a N2 atmosphere followed by chemical activation with 1 M KOH and 1 M HCl. The AC was characterized by scanning electron microscopy, surface area analysis, and Fourier transform infrared spectroscopy. Adsorption of PAHs from aqueous solutions through AC was examined by batch adsorption tests. The optimum parameters for maximum adsorption of PAHs were found to be: initial PAHs concentration 40 ppm, 2 h contact time, pH 3, 5, and 7, 50 °C temperature and adsorbent dose of 0.8 g. Kinetic and isotherm models were applied to evaluate the adsorbent capacity for PAHs adsorption. The kinetic study shows that the adsorption of these PAHs onto AC follows pseudo-second-order kinetics. The experimental results demonstrated that the Langmuir isotherm model best fitted the data. The thermodynamic factors calculated such as entropy change (ΔS°), enthalpy change (ΔS°) and free energy change (ΔG°) show that the adsorption process is non-spontaneous and endothermic in nature. Results were also compared with the efficiencies of some commercial adsorbents used in practice. This examination revealed that the novel plastic-derived AC possesses a great potential for elimination and recovery of PAH elimination from industrial wastewater.
Highlights
polycyclic aromatic hydrocarbons (PAHs) are recalcitrant and toxic organic pollutants, and consist of two or more fused benzene rings in linear, cluster or angular arrangements, and are associated with low water solubility ( Johnsen & Karlson 2005)
The activated carbon (AC) synthesized from waste polyethylene terephthalate (wPET) and waste polystyrene (wPS), i.e., wPET-AC and wPS-AC were characterized by SEM, FTIR, and SSA analysis
The SEM micrographs of wPET-AC (Figure 2(b)), show a stretched but uneven morphology, with some fine particles agglomerated on the surface
Summary
PAHs are recalcitrant and toxic organic pollutants, and consist of two or more fused benzene rings in linear, cluster or angular arrangements, and are associated with low water solubility ( Johnsen & Karlson 2005). The PAHs are released from anthropogenic sources as well as from some natural sources. The natural sources of PAHs in the environment are insignificant (Witt 1995; Charlesworth et al 2002). Among the different anthropogenic sources accountable for the PAH emissions, residential waste burning, agricultural processing, vehicular emissions, military operations, coal tar production, asphalt and shale oil production, coal conversion, metal working, petroleum processing, steel and iron foundry works, aluminum smelting and coke production and incomplete combustion are notable (Ravindra et al 2008; Hall et al 2009). PAHs are commonly used in lubricating materials, wood preserving, agricultural and pharmaceutical products, resins, dyes, pesticides, and the manufacture of pigments (Abdel-Shafy & Mansour 2016). PAHs are ubiquitous in tar deposits, coal and oil, and PAHs mostly in the aquatic system have originated from contaminated sediment, atmosphere deposition, and accidental leakage (USEPA 1994; Blanchard et al 2004)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
