Adsorption and desorption of metals on ferrihydrite: reversibility of the reaction and sorption properties of the regenerated solid

Journal Article · Tue Sep 01 00:00:00 EDT 1987 · Environ. Sci. Technol.; (United States)

DOI:https://doi.org/10.1021/es00163a003· OSTI ID:5611818

Schultz, M F; Benjamin, M M; Ferguson, J F

The feasibility of recycling ferrihydrite in a metal adsorption process was investigated. In this process, metal ions are removed from dilute solution by sorption onto ferrihydrite and are then desorbed into a more concentrated solution at lower pH. The ferrihydrite thus becomes available for reuse in subsequent sorption operations. Copper, lead, nickel, zinc, cadmium, and chromium(III) can be quantitatively sorbed onto ferrihydrite at pH 9.5. Lowering the pH to 4.5 substantially desorbs the metals. However, for all metals except cadmium, a measurable fraction of the bound metal is not easily desorbed. This fraction increases with increasing pH and duration of the high-pH stage and increases more or less continuously in sequential cycles. The retention of metals in the solid does not interfere with sorption in subsequent cycles, within the range of concentrations investigated. This included retention of up to 0.7 mol of Cr(III)/mol of Fe in the adsorbent. This process has the potential to provide the advantages of sorption processes, including low residual soluble metal concentrations, moderate pH requirements, and simultaneous removal of several metals, without excessive sludge production.

• Research Organization: Univ. of Washington, Seattle
• OSTI ID: 5611818
• Journal Information: Environ. Sci. Technol.; (United States), Vol. 21:9
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
CADMIUM
ADSORPTION
CHROMIUM
COPPER
LEAD
NICKEL
ZINC
EXPERIMENTAL DATA
MUNICIPAL WASTES
SEWAGE SLUDGE
WASTE MANAGEMENT
WASTE PROCESSING
DATA
ELEMENTS
INFORMATION
MANAGEMENT
METALS
NUMERICAL DATA
PROCESSING
SEWAGE
SLUDGES
SORPTION
TRANSITION ELEMENTS
WASTES
420900* - Engineering- Waste Processing Plants & Equipment- (-1989)