MTC18 hot topics are ZLD, and public outreach
The Membrane Technology Conference 2018 kicked off in Florida, US, with a panel debate on the pros and cons of membrane treatment technologies.
Management of brine in reverse osmosis (RO) systems was named as the big challenge for the membrane industry, and is the subject of a number of papers at this year’s event.
“The achilles heel of all membrane separation processes is the reject stream, particularly in RO, the challenge is the salt. There is no good way to remove salt other than physical separation,” said Eva Steinle-Darling, WateReuse board member. Steinle-Darling noted the project in El Paso, Texas, which is persevering with an ongoing project to achieve zero liquid discharge (ZLD) from RO.
Brent Alspach, AMTA president and director of applied research at Arcadis, added that he anticipates ZLD technologies will be more widely adopted in the future. “You will see more ZLD in the future, and not just boutique cases where the water is amenable, but with crystallizers. The question will be, ‘Do I have water, and am I willing to pay for the technology?’”
On the plus side, membrane treatment is considered useful particularly when public outreach and education are needed, because a physical barrier is simple to explain and to understand.
“Public perception is the big issue and if you have an issue with that, membranes are a plus. You have a barrier and anything that’s too big is not getting through,” said Melissa Meeker, co-CEO, Water Research Foundation.
The next bit step for potable reuse systems using membranes will be to establish reliable online integrity testing — an advance that’s expected to happen relatively quickly. “Membranes are the benchmark for taking out pathogens. We test them because we can, and we aren’t far away from being able to validate water quality for potable reuse. There will be online integrity testing within five years,” said Alspach.