Advanced characterisation of organic matter in desalination pre-treatment

NCEDA project summary: 

Low-pressure porous membranes are increasingly considered for pre-treatment of sea and brackish waters. However, membrane fouling remains a major drawback, as it results in high operating, maintenance and cleaning costs. Through the development and validation of techniques for advanced characterisation of the organic compounds present in feedwaters, this project aims to better understand and to optimise the strategies currently used for fouling control. The relative efficiencies of both physical (relaxation, backwashing) and maintenance chemical cleanings will be assessed on lab and pilot scales. The organic and inorganic natures of the irreversible fouling formed during long-term filtrations (and repeated cleanings) will be characterised in details, allowing recommendations for sustainable operation and performance. 

 

Image: Desalination membranes in action (Photo credit: Pierre Le-clech)

Masters project summary: 

Reverse osmosis (RO) is a well-known treatment process for the provision of drinking water from brackish and seawater. However, fouling of RO systems due to the presence of inorganic suspended solids, bacteria, and dissolved organic in the feedwater remains a major operational issue. Organic matter is the most recalcitrant among the many potential membrane foulants and its pre-treatment remains a key issue influencing the operation and maintenance costs. As organic matter comprises a heterogeneous mix of molecules, advanced characterisation methods are needed to quantify and qualify the organics fractions in seawater and brackish water to provide insights into the RO treatment process performance. An additional potential opportunity of advanced characterisation lies in developing more rapid and accurate screening of feedwaters and pre-treatment performances. This could lead to the reduction of the amount of pilot scale testing needed as well as the optimisation of pre-treatment options for desalination. The purpose of this research project is therefore two-fold:

  1. To determine the character of the organics of feedwater to desalination plants in Australia by using state-of-the-art techniques including liquid chromatography-organic carbon detection (LC-OCD), fluorescence excitation emission matrix (FEEM) spectroscopy, and assimilable organic carbon (AOC) and biodegradable dissolved organic carbon (BDOC) measurements
  2. To assess the organics removal using pre-treatment strategies, such as dissolved air flotation (DAF) and ultrafiltration, and investigate the impact of these pre-treatment on membrane bio-fouling

 

Project Funding Source(s), Industrial Partners and Period

  • National Centre of Excellence in Desalination Australia (NCEDA) Project: Funding Round 2 (2011-2013)
  • Siemens
  • Veolia Water Australia
  • Water Corporation
  • Evoqua Water Technologies
  • Water Research Australia

Chief Investigators

Partner Investigators

Research Associate(s)

  • Dr. Adam Hambly

PhD/ Masters Candidates

  • Dr. Adhikara Resosudarmo
  • Mr. Barun Lal Karna