Watermaker versus Micro-plastics

[TonyDove]

Hi all
Couldn't find anything about this when I searched … so here's a question for anyone with knowledge of the subject.

With the increasing amount of micro-plastic pollution in the oceans these days, how do Watermakers cope? Are the primary filters of sufficiently small mesh size as to exclude micro-plastics from the working osmotic membrane(s)? Is it just a case of backwashing the primary filters more often or is something more required?

Regards and safe sailing to all

[Nicholson58]

Primary is 5 micron. No problem

[GordMay]

“Drinking Boiled Tap Water Reduces Human Intake of Nanoplastics and Microplastics” ~ by Zimin Yu et al
➥ https://pubs.acs.org/doi/10.1021/acs.estlett.4c00081

A group of researchers, from Guangzhou Medical University and Jinan University, in China, discovered that boiling drinking water has resulted in eliminating a good portion of the nano and microplastics [NMPs] in a study that was published, in February.

The team found offered evidence that polystyrene-, polyethylene-, and polypropylene-based NMPs can co-precipitate with calcium carbonate (CaCO3) incrustants, in tap water, once boiled.

The outcome was that boiling hard water can remove at least 80 per cent of polystyrene, polyethylene and polypropylene NMPs ,that are between 0.1 and 150 μm in size. In some instances, with certain types of water, up to 90 per cent of the plastics were removed.

[Statistical]

The membrane itself is is 0.001 micron so plastics won't get through that although in theory they could clog them. Never noticed an issue. Primary filter is usually 5 or 10 micron so it will block all but the smallest micrplastics. If poor membrane life due to clogging/damage from microplastics ever became a widespread problem the solution would probably be just to add another filter. A 0.5 or 1 micron filter after the 5/10 micron one.

[Lepke]

Because I also make water in fresh water that may contain silt, I use several filters, the last a 1 micron. A side benefit is my TDS in salt water is low, usually well below 150.
Using bigger filters causes the water to flow thru much more slowly, catching smaller particles. I use 4.5x20.

[GordMay]

EPA researchers define microplastics, or MPs, as plastic particles, ranging in size from 5 millimeters (mm), which is about the size of a pencil eraser, down to 1 nanometer (nm).

A nanometer is equal to one billionth of a meter, one ten-millionth of a centimeter, a millionth of a millimeter, or 1,000 micron [μm].

One micrometre [micron, μm] is equal to 1/25,400 of an inch, or one-millionth of a meter.

➥ https://ars.els-cdn.com/content/imag...95-ga1_lrg.jpg