Cascade Water Treatment system and mass balance Fe and Mn

Dear all expert,

I just learn and curious how to reduce Fe using a cascade type rectangular water treatment system that can reduce Fe or Mn? The source of raw water from Groundwater tubewell capacity 200 m3 per hour with influent Fe 6 ppm , the process from Raw water - Cascade-Sedimentation - Sand Filtration-Clear Water-OHT ? can help me or if have reference really helpful, Regards and Stay healthy  for you all