Water. Desalination + reuse
Issue link: https://fhpublishing.uberflip.com/i/946410
14 On Site March 2018 Water.desalination+reuse The two most signi cant challenges for membrane practitioners continue to be cost and, for desalination, concentrate management. In most cases, membrane processes produce the best quality water, but the cost-bene t analysis can be unfavourable. Membrane ltration — micro ltration (MF) and ultra ltration (UF) — consistently yield ltrate with turbidity levels near 0.02 NTU, independent of feed water quality; and, barring an integrity breach, MF and UF serve as a near-absolute barrier for bacteria and regulated protozoa, including giardia and cryptosporidium. Further, UF provides high rejection of viruses. Additionally, MF and UF can achieve more than 4-log, or 99.99 per cent, reduction of important unregulated pathogens such as legionella, naegleria fowleri, the so-called brain-eating amoeba, vibrio cholerae, which causes cholera, and leptospira, the bacteria behind the spread of leptospirosis through Puerto Rico in the aˆ ermath of Hurricane Irma in 2017. These substantial water quality bene ts are largely unmatched among ltration technologies, however MF and UF are oˆ en compared to conventional processes such as dual media ltration. Dual media ltration uses less expensive equipment (the considerable cost of concrete basins, where applicable, notwithstanding), and operates by gravity ' ow, resulting in operational cost savings compared to the expense of the pumping required by membrane ltration (see feature, page 20).' Membrane desalination processes — nano ltration (NF) and reverse osmosis (RO) — in addition to removing salts, reject a wide range of emerging contaminants, including pathogens, pharmaceuticals/personal care products (PPCPs), The main drivers of advancements in desalination concentrate management are maximising the yield of potable water, and limiting residuals streams.'Many innovations in concentrate management are not merely on the horizon, but are already in limited, full-scale deployment, or undergoing pilot testing, with the promise of making desalination more feasible, e— cient, and/ or economical. These advancements largely manifest in two categories: brine concentration; and resource recovery.'Activity in brine concentration is robust, with at least ve or six very promising technologies primed for market penetration.'Each has unique advantages and optimum conditions for use, and all are likely to be adopted among the myriad of diverse desalination applications. The technology for resource recovery (for example The most signi cant industry-wide trend is the increasing use of poorer-quality, alternative water supplies, ultimately for potable use, including brackish groundwater, recycled wastewater, stormwater, grey water, and seawater.'In Florida and California, which both have large populations and long-term water resource challenges, it is easy to imagine all ve sources being used as potable supplies at varying scales of implementation, from households to municipal service areas. Treatment of any such sources may require use of membranes in a comprehensive treatment strategy, and all The American Membrane Technology Association (AMTA) works actively to counter the challenges outlined above. We partner with the American Water Work Association (AWWA) to organise the world's premier membrane treatment event, the annual Membrane Technology Conference in the US, and this year, we have extended this partnership to include Water Environment Federation and WateReuse Association. AMTA runs ve technology transfer workshops each year across the US, to broaden understanding of membrane treatment and to discuss the latest advancements.'Among other things, these workshops aim to communicate that even in applications for which membranes are not the cheapest option, the technology brings many additional advantages that should be factored into a cost-bene t analysis.' Further, we engage with elected o— cials and government agencies to provide education about the bene ts of membrane technology. In an era of unprecedented water demand, drought, and a changing climate, water systems around the US are by necessity using lower quality supplies to expand and diversify their resource portfolios. Membranes can transform the poorest quality water into the best, and government-funded research, aimed at reducing energy consumption What are the biggest challenges for membrane specialists right now ? Where's the innovation in membrane technology ? How do membrane technologies fi t into the wider trends in water ? What activities form the core of AMTA's work ? Brent Alspach is president of AMTA and director of applied research at Arcadis Q & A B R E N T A L S P AC H "The need for membrane treatment has never been more acute" On Site March 2018