Degradation of organic contaminants through the activation of oxygen using zero valent copper coupled with sodium tripolyphosphate under neutral conditions

In this study, sodium tripolyphosphate (STPP) was used to promote the removal of organic pollutants in a zero-valent copper (ZVC)/O 2 system under neutral conditions for the first time. 20 mg/L p-nitrophenol (PNP) can be completely decomposed within 120 min in the ZVC/O 2 /STPP system. The PNP degradation process followed pseudo-first-order kinetics and the degradation rate of PNP gradually increased upon the decreasing ZVC particle size. The optimal pH of the reaction system was 5.0. Our mechanism investigation showed that Cu + generated by ZVC corrosion was the main reducing agent for the activation of O 2 to produce ROS . ·OH was identified as the only ROS formed during the degradation of PNP and its production pathway was the double-electron activation of O 2 (O 2 →H 2 O 2 →·OH). In this process, STPP did not only promote the release of Cu + through its complexation, but also promoted the production of ·OH by reducing the redox potential of Cu 2+ /Cu + . In addition, we could initiate and terminate the reaction by controlling the pH. At pH < 8.1, ZVC/O 2 /STPP could continuously degrade organic pollutants; at pH > 8.1, the reaction was terminated. STPP was recycled to continuously promote the corrosion of ZVC and O 2 activation as long as the pH was <8.1. This study provided a new and efficient way for O 2 activation and organic contaminants removal.