The removal of sulphuric acid from natural and industrial waste waters

✍ Scribed by A.E. Simpson; C.A. Buckley

• Publisher: Elsevier Science
• Year: 1988
• Tongue: English
• Weight: 595 KB
• Volume: 70
• Category: Article
• ISSN: 0011-9164
• DOI: 10.1016/0011-9164(88)85071-9

✦ Synopsis

A process is described which enables the removal of sulphuric acid from effluents without the addition of chemicals to the effluent.

The technique employs an anion selective membrane which separates the acidic effluent from a lime solution.

In the case where no current is applied, facilitated transport occurs and the driving force for the demineralisation process is the difference in the chemical potential of the species on either side of the membrane. The equilibrium position may be shifted by the passage of a current through the membrane, in which instance the driving force becomes the applied electric potential.

The sulphates are removed as calcium sulphate, which precipitates in the lime solution. The specific membrane area reauirements are a function of the desired dearee of acid reduction.

The application of -low current densities (500 A/ms) reduces -the specific membrane area requirements for a particular duty by two orders of magnitude compared to facilitated transport.

Results of laboratory investigations are given and indicate that the sulphuric acid component can be removed from waste waters without an undesirable build-up of additional dissolved solids.