Influence of Temperature on the Removal of Extremely High Concentrationp-Nitrophenol Simulated Wastewater by Fe/Cu/H2O Systems

In this study, the effect of the operating temperature on the removal of high p-nitrophenol (PNP) concentrations by Fe/Cu/H2O systems has been investigated thoroughly. The results suggest that only a higher operating temperature (>40°C) could significantly improve the removal efficiency of high PNP concentrations (e.g. 10 000 mg/L) by Fe/Cu/H2O systems. Meanwhile, a lower PNP concentration (e.g. 500 mg/L) could be completely removed by Fe/Cu/H2O systems only at 40°C. Furthermore, the interaction between the operating temperature (10–85°C) and other key operating parameters including theoretical Cu mass loading (0–0.89 g Cu/g Fe), Fe/Cu dosage (5–35 g), stirring speed (0–400 rpm), electrolyte (0–50 mmol/L NaCl or Na2SO4), and initial pH (3.–12) was investigated, respectively. In particular, the elevating temperature could decrease theoretical Cu mass loading, Fe/Cu dosage, stirring speed and electrolyte, and abroad the range of initial pH, which could reduce the operating cost of Fe/Cu/H2O systems if the waste-heating vapor could be used to elevate the operating temperature. According to the results of UV-Vis spectra, for total organic carbon and chemical oxygen demand, it is clear that the elevating temperature could facilitate mineralization of PNP in an aqueous solution by Fe/Cu/H2O systems. As a result, the operating temperature was a main factor for the removal of pollutants by Fe/Cu/H2O systems.