Water Journal : Water Journal September 2013
SEPTEMBER 2013 water 43 Conference report Government recognised the need for a radical new source of supply. The result was the decision to embark on construction of a seawater desalination plant, a brave initiative at the time, but one that has proved to be a saviour in terms of providing a safe, reliable supply of drinking water for Perth. Intelligent planning has ensured that the concerns about environmental impacts from carbon emissions, energy use, concentrate discharge and ecosystem degradation have proven to be without foundation. Peter then moved on to talk about the groundwater replenishment schemes that have been the most recent focus of studies of public acceptance of the safety of using reuse water drawn from the Leederville Aquifer, after storage. The positive response to the concept has encouraged the Water Corporation to further pursue the possibility of using aquifer recharge with purified water and subsequent redraw of water in the other two aquifers, thereby greatly boosting Perth’s resilience to future supply risks. The Asia Pacific element in the Conference title was amply fulfilled from the welcome attendance and presentations by Dr Haifeng Jia from Tsinghua University, who provided a most interesting overview of China’s efforts to secure water supply for its people, with a focus on water recycling initiatives. He cited an example of stormwater harvesting in the city of Suzhou near Shanghai. Another important speaker was Dr PC Chiang from Taiwan, whose work focused on removing persistent pollutants from water. Delegates from Japan, the Republic of Korea, and the Asia Pacific Desalination Association were also in attendance. Day 2 ProceeDings On Day 2 of the event, membrane technologies and desalination took centre stage. Dr Harry Ridgeway, Visiting Research Scientist at King Abdulla University of Saudia Arabia, delivered a fascinating talk highlighted by brilliant photographic images from scanning electron microscope (SEM) work on the behaviour of bacteria on the surfaces of membranes – which, by their tendency to adorb onto and into the pores, limit the passage of water molecules. Key to this fouling behaviour is that the build-up of biofilm on the membrane appears to be exopolymeric substances (EPS) extruded by the bacteria, strands of which could be seen under the SEM as they lie on the membrane surface. The EPS appear to behave as a hydrogel, have a complex biochemistry, 98 per cent water by weight and contribute to the hydraulic resistance of the biofilm. However, these apparent properties pose a conundrum: a biofilm (of which the EPS material is a critical component) is a hydrogel, so why does it retard the passage of water and what is the mechanism for this resistance? The second speaker for Day 2 was Professor In S Kim from the Republic of Korea, who leads the country’s National Centre for Seawater Desalination Plant (Sea Hero), a research hub for water supply centred on desalination technologies. The main focus of the Sea Hero R&D program is achieving eco-friendly design for seawater desalination plants. There are four key paths: 1. Core technologies – e .g. doubling the size of the vessels to better accommodate 8” to 16” membranes in larger trains for improved efficiency, including attention to the O rings resulting in a male- female interlocking device that provides a more stable and secure housing for the membrane itself; 2. Materials and devices – e .g. researching improved fabrication of high performance SWRO membrane, high pressure pumps – less noisy and less vibration; 3. Innovation in design and construction – optimising the pre- treatment process is a priority and the researchers are working with an innovative DAF unit with Ball Filter; 4. O&M technology – here the research team is developing a dynamic SWRO process simulator. These key speakers for the two Conferences provided a magnificent opportunity on both days for the following sessions outlining research work and project management undertaken by AWA’s members and their colleagues. The Conference Dinner provided an excellent opportunity for everyone to meet AWA’s new Chief Executive, Jonathan McKeown, who gave a brief introduction to his recent work in Thailand during its own flood crisis and for him to also greet the representatives from countries in our region. From left: Don Begbie, Dr Oz Sahin, Dr Harry Ridgeway, Professor Kim, Neil Palmer and Peter Hillis at the first M&D session on Day 1. Adam Lovell from WSAA presents keynote speaker Dr Shane Snyder with a thank you gift.
Water Journal August 2013
Water Journal November 2013