Studies in desalination and water treatment

Program Code: 
1871
Contact: 

Prof Ric Pashley (r.pashley@adfa.edu.au)

Description of Work: 

Brief outline of the proposed research project

There are several projects in desalination and water treatment. Each project is directly linked to commercial applications.

  1. We recently developed a novel bubble column evaporator (BCE) method for measuring the latent heat of vaporization (  Hv)of concentrated salt solutions. [see: J. Phys.Chem. B 113, 9311-9315 (2009).] However, although established in principle, the method used was crude and hence only gave values to about 3% accuracy. There is a need to develop an improved method which will enable new values to be obtained for concentrated electrolyte solutions, above 1M. A second part of this project involves the study of the BCE as new method for the controlled production of fine particles.
  2. The two main industrial processes for seawater desalination are membrane reverse osmosis (SWRO) and thermal distillation (such as MSF methods). However, both methods have some serious disadvantages. Mixed bed ion exchange resins have been used for many years to remove scale-forming ions such as Ca2+ and Mg2+ from feed water and to produce distilled quality water from tap water. However, this process could, in principle, also be applied to the desalination of seawater, overcoming the main disadvantages of the current methods. The aim of the project is to develop a specifically designed ion exchange resin suitable for the efficient desalination of seawater and brackish water.
  3. We previously established that at high salt concentrations, air bubble columns can be produced at high bubble volume fractions without the bubbles coalescing. As they pass through the column, these bubbles rapidly pick up water vapour, which can then be condensed to produce high drinking quality water. This system will be developed and studied for its potential application as a sustainable, energy efficient seawater desalination process.
  4. We are currently working with a NSW company on a new combined blackwater/greywater household treatment and recycling system. Currently, 17% of households in Australia treat their waste water on site. Mostly they use septic tanks which are hard to maintain and often leak contaminated water into the groundwater. A novel household treatment and recycling unit will not only prevent this contamination but will also reduce household water usage.