The common way to treat this wastewater is alkaline neutralization.
By means of adding alkali liquor and aerating, Fe2þ can convert to Fe3þ by oxidation and pH will increase.
With the increase of pH, a great quantity of brownish black sediment will generate mainly composed of Fe(OH)2 and Fe(OH)3.
After sedimentation, the supernatant can be discharged meanwhile iron-containing sludge is obtained