Fenton and Fenton-like reaction followed by hydroxide precipitation in the removal of Ni(II) from NiEDTA wastewater: A comparative study

It is difficult to remove Ni(II) from NiEDTA wastewater by many conventional processes. A new method for removing Ni(II) from NiEDTA wastewater by Fenton and Fenton-like reaction followed by hydroxide precipitation presents an important breakthrough. This treatment process is referred to as Fenton/Fenton-like reaction-hydroxide precipitation (FR-HP) process. This study investigated the use of FR-HP process for the removal of Ni(II) from NiEDTA complex wastewater. The removal efficiency of Ni(II) by FR-HP process was investigated and the kinetics of the two processes was studied. Results indicated that the removal efficiency was strongly dependent on the initial concentration of Fe2+ or Fe3+ and H2O2, initial and precipitation pH and temperature. Both FR-HP processes can effectively remove Ni(II). At optimal operation conditions, the removal efficiency of Ni(II) were 92.8% and 94.7% for Fenton and Fenton-like systems after 60 min, respectively. FR-HP process seems to be an economically and environmentally friendly process to remove the metal from metal–EDTA wastewater. Hopefully, FR-HP process will promote the development of metal–EDTA treatment technology.