• AWWA ACE91097
Provide PDF Format

Learn More

AWWA ACE91097

  • Selective Alum Recovery From Clarifier Sludge: A New Two-Step Process Using Composite Membranes
  • Conference Proceeding by American Water Works Association, 01/01/1991
  • Publisher: AWWA

$12.00$24.00


Acidic extraction of aluminum hydroxide from alum sludges has two problems: it is nonselective (it recovers all other substances that are soluble under highly acidic conditions or exist as colloids) and concentrations of heavy metals could warrant problems if recycled through recovered alum. This paper describes an alternative, two-step process: selective sorption of Al(III) followed by desorption or regeneration of composite membranes. Results of laboratory experiments show that the two-step process can selectively recover Al(III) from the background of natural organic matter, manganese, and other heavy metals. Organics and heavy metals carry over into the recovered alum but were, on a percentage basis, always much lower than Al(III) recovery. An increase in Cd(II) concentration in the spiked sludge did not increase Cd(II) concentration in the recovered alum, indicating excellent rejection of heavy metals. The composite membrane can be regenerated very efficiently with dilute sulfuric acid. After 30 cycles of batch operation, there was practically no reduction in Al(III) uptake by the composite membrane, indicating durability of the membrane.

Related Products

AWWA WQTC60611

AWWA WQTC60611

Comparison of an Anionic Polymer to No Polymer Addition for Treating Filter Backwash Water..

$12.00 $24.00

AWWA MTC64524

AWWA MTC64524

Integrated Approach to Construction and Startup of the 96 mgd Lakeview WTP for the Region of Peel..

$12.00 $24.00

AWWA INF52174

AWWA INF52174

Field Performance Monitoring of a Sliplined Watermain..

$12.00 $24.00

AWWA ACE59836

AWWA ACE59836

Water Conservation in Georgia Bringing Efficiency into Mainstream Thinking..

$12.00 $24.00