Water. Desalination + reuse
Issue link: https://fhpublishing.uberflip.com/i/86284
RESEARCH Four red-tide lessons Four clear messages need to be taken from the recent workshop on red tides held in Oman, according to veteran desalter David Furukawa, chief scientific officer of the Australian National Centre for Excellence in Desalination (NCEDA). NCEDA co-sponsored the workshop in February 2012 with the Middle East Desalination Research Centre, and the King Abdullah University of Science & Technology of Saudi Arabia. Furukawa's conclusions appear in the 5 March 2012 edition of NCED's Desal Directions. "It appears that toxins are not the major identify those which are of most interest." Lessons that need to be noted, he said, were: 1. Industry badly needs a real-time monitoring tool that is effective for detecting algal blooms 2. There is no published data yet on real- life operation of desalination plants during toxin producing algal blooms 3. Compound transformation during desalination, through the impact of issue, but rather biomass that affects desalination plant operations," Furukawa writes. "With the many varieties of 'critters' involved in the problem, it is a challenge to 4. While red tides usually exist on the surface, the bloom can move up and down in the water column, meaning that a deep-water intake does not necessarily prevent drawing biomass into a plant. chlorine and flocculants, needs to be defined Australian researchers report portable CDI trial A portable capacitive deionisation (CDI) desalination unit being developed and tested by the University of South Australia has demonstrated sufficient salinity and hardness removal ability. The trial, at Wilora, a remote community in the Northern Territory, is supported by the Australian National Centre of Excellence in Desalination (NCEDA), which reported on the research in the 5 March 2012 edition of Desal Directions. The CDI research is being led by Professor Linda Zhou, whose work was featured in D&WR's August/September 2011 article on the NCEDA. Her team, with USA researchers Dr Wei Zhang and PhD student Mohamed Mossad, has conducted a series of trials to evaluate the performance of a portable commercial CDI unit developed by Texas-based Aqua EWP. The trials found that the CDI unit demonstrated sufficient salinity and hardness removal ability at the remote brackish water source. The increased flow rate tend to decrease the overall TDS removal efficiency. However, in terms of energy efficiency, a higher flow rate tended to be favourable. MD pilot success with waste heat Results from an Australian trial to demonstrate the potential for a membrane distillation (MD) process to exploit waste heat from heavy industry to desalinate saline effluent have shown the system can produce high-quality water at temperatures as low as 30°C without an increase in greenhouse-gas emissions. A team from Victoria University's Institute for Sustainability & Innovation operated a 240 L/d pilot plant over three months in late 2011 using waste heat from Ecogen Energy's 500 MW Newport Power Station. The trial was carried out in partnership with City West Water (Melbourne), GWMWater and Water Quality Research Australia. The pilot plant treated effluent from an ion-exchange demineralisation plant of approximately 3,000 mg/L TDS. The trial showed that permeate flux was relatively consistent up to reject concentrations of 62,300 mg/L, after which flux decline was observed. achieved in the final phase of the trial was 92.8% with a reject concentration of 71,400 mg/L and salt rejection of 99.97%. The experiment successfully tested the MD process' longevity and robustness, demonstrating a system driven by waste heat at input temperatures as low as 30°C, which achieved permeate flux of 3–4 L/hr/m2 The maximum water recovery of highly desalinated water. Membrane bioreactor research report published by WRA The WateReuse Association has published the results of research it commissioned to achieve a better understanding of the effluent quality produced from a membrane bioreactor (MBR) system as a function of MBR design and operating conditions. Although the effluent water quality of MBR processes has been reported to be superior to that of conventional activated sludge systems, largely attributed to the membrane barrier, the water quality performance of pilot- and full-scale MBR processes indicate varying degrees of performance with respect to microbes, nutrients, aggregate organics, trace organic compounds and trace metals. Investigation of Membrane Bioreactor Effluent Water Quality and Technology Treatment Technologies (www.watereuse.org/product/06-007-1) reports on a number of tasks, including: l Comprehensive analysis of MBR effluent quality and operational data collected from a wide variety of sources l Comprehensive analysis of data obtained through surveys of vendor suppliers and operating full- scale installations; and that included peer-reviewed and grey literature of pilot studies and full-scale plant operations; l Synthesis of data obtained for aggregate organics and trace organic compounds with the predictions of a mechanistic MBR model developed to simulate different operating scenarios. May-June 2012 | Desalination & Water Reuse | 43 |