Evaluation of ion-exchange properties of ferric hydroxide flocs for the removal of heavy metal wastes using a high gradient magnetic separator

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1984

OSTI ID:5835517

Anand, P

Preliminary adsorption studies showed no effect on the effluent heavy metals with a magnetite dose of 500 or 1000 mg/l but removal was lower when 200 mg/l of magnetite was used. Adsorption of metals onto ferric flocs was found to be independent of initial heavy metals concentration provided the surface available for adsorption of ions was not saturated. As surface area coverage approached saturation percent, removal of heavy metals decreased. The pH of the medium was found to have a major influence on the removal of heavy metals. A 99.9% removal of all heavy metals could be achieved at pH values greater than 10.30-10.50, but removal was almost totally due to precipitation. Ferric sulfate made removal of heavy metals in a HGMS possible at lower pH values than 10.30 to 10.50. Increased magnetic field strength caused more removal of flocs for a given flow rate whereas an increase in flow rate decreased removal of flocs in a HGMS. The effect of treatment column diameters was geometric in that an increase in tube diameter caused more floc to be trapped because more entrapment area was available. The mg/in/sup 3/ of floc removed in each tube tested was the same at constant flow rate and magnetic field strength.

• OSTI ID: 5835517
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420900* -- Engineering-- Waste Processing Plants & Equipment-- (-1989)
CONCENTRATORS
ELEMENTS
FLOCCULATION
HYDROGEN COMPOUNDS
HYDROXIDES
ION EXCHANGE
IRON COMPOUNDS
IRON HYDROXIDES
MAGNETIC SEPARATORS
MANAGEMENT
METALS
OXYGEN COMPOUNDS
PERFORMANCE
PH VALUE
PRECIPITATION
PROCESSING
REMOVAL
SEPARATION PROCESSES
SURFACE AREA
SURFACE PROPERTIES
TRANSITION ELEMENT COMPOUNDS
WASTE MANAGEMENT
WASTE PROCESSING