Forward Osmosis (FO)

Forward Osmosis (FO)

Coming soon: DME e.V. Desalination Technology Map – Moers – Germany

Coming soon: DME e.V. Desalination Technology Map
Dienstag, Dezember 19, 2017

Comprehensive overview on 17 desalination technologies (part 1)

(in alphabetical order):

CDI – Cpacitive Deionization

ED/EDR – Electrodialysis (Reverse)

EDI – Electrodeionization

FD – Freeze-Thaw Desalination

FO – Forward Osmosis

GH – Gas Hydrates

HD – Humidification-Dehumidification

IX – Ion Exchange

MED – Multi-Effect-Distillation

MD – Membrane Distillation

MDC – Microbial Desalination Cells

MSF – Multistage Flash Evaporation

MVC – Mechanical VApor Compression

OTED – Ocean Thermal Energy Desalination

RO – Reverse Osmosis

RSE – Rapid Spray Evaporation

TVC – Thermal Vapor Compression

Introduction to the fundamentals of desalination (part 2)

Posted by Peter Tillack

(LINK!)

MIT suggests a different approach to reducing the rate of fouling – USA

The prevailing idea in the industry has been that the high pressure required by RO is responsible for the relatively high rate of fouling, compared to other systems such as forward osmosis. But the MIT study shows that this is not the case, a finding that opens up new approaches to reducing fouling in RO. The research, by Emily Tow ’12, SM ’14, PhD ’17 and MIT Professor John H. Lienhard V, was recently published in the Journal of Membrane Science and presented at the 2017 AMTA/AWWA Membrane Technology Conference, where it received the Student Best Paper Award.

Many experts believe that the high pressure in an RO system compresses the microbial mats that grow on the membranes, and that this “compaction” makes the growth much harder to remove. In contrast, in low-pressure forward osmosis (FO) systems, which are less energy-efficient but more fouling-resistant, the supposedly looser mat is thought to be easier to clean off.

However, these microbial mats are generally full of water, which does not compress under RO pressures, so “there is no good reason why high pressure should worsen fouling,” Tow says. She compares the microbes to a scuba diver: “There’s a lot of pressure at the bottom of the ocean, but it doesn’t make you stick to the seafloor.” But if pressure doesn’t matter, and the flow rates through FO and RO systems are similar, what could account for the disparity in fouling resistance?

(LINK)