Removal of nickel from Ni(II)-NH3-SO2-CO2-H2O system by electrocoagulation, sedimentation, and filtration processes

The nickel removing by electrocoagulation of Ni(II)-NH3-CO2-SO2-H2O system was studied in a batch reactor 50 L useful volume, with stirring, and two pairs aluminum electrodes. operating parameters were concentration between 255 342 mg L-1, current density 11.0 16.6 mA cm-2, pH 8.34±0.06, mean temperature 58.4±3.9 oC retention time min. maximum removal 99.7 % at specific energy consumption 16.86 kWh kg-1 Al3+, 2.438 Ni the adsorption capacity 5819 g-1 Al3+. precipitate contained 37.2 true 2720 kg m-3, hydro­talcite-like structure layered double hydroxides. unit area sedimentation 0.25 1.96 m2 t-1 day, from 971 to 1019 m-1 53±4 oC. A model for pre­dicting cake resistance estimated as function pressure drop sus­pension 44.45 kPa 59.52 resulting value 6.47±107 m kg-1. average humidity 88 base humid.