What is hollow fiber RO membrane? Easy guide for beginners to learn the basics and key features in simple terms!

I spent the whole day messing with this hollow fiber RO membrane thing, and let me tell you, it was a doozy. I’ve been wanting to get into water filtration for a while now, just as a personal project, you know? Always been fascinated by how we can take nasty water and make it drinkable.

So, I finally got my hands on one of these hollow fiber membranes. They’re basically a bunch of tiny, straw-like tubes bundled together. I started by picking up this kit online. When the package arrived, I ripped it open, eager to see what was inside. There it was, a bundle of what looked like thin, white straws.

• First Impressions: They’re super thin, like, way thinner than a regular drinking straw. Maybe 0.5 to 1 mm in diameter.

I spent a good chunk of time reading up on these things. Seems like they’re either “isotropic” or “anisotropic”. I still don’t get all the fine details of it. Basically, the wall structure of these tiny tubes is what makes them work. Some let stuff through easier than others, it depends on the structure.

Setting up the experiment

Next, I needed to set up some kind of rig to test this thing out. I grabbed some old PVC pipes, some fittings, and a couple of buckets. One bucket would hold the dirty water, and the other would catch the clean water. I connected the membrane to the pipes, making sure everything was sealed tight. This is where things got a little tricky, as those tiny fibers are delicate. I connected the PVC contraption to a pump I had lying around from an old project, that would force the water through the membrane. This is basically reverse osmosis. The idea is that only the clean water makes it through, leaving all the gunk behind.

• The Setup: Two buckets, some PVC pipes, fittings, a pump, and the membrane.

I filled the first bucket with some really murky water. I figured I’d really put this membrane to the test. I turned on the pump, and slowly, water started to drip into the second bucket. It took a lot longer than I thought it would.

I watched as the clean water bucket slowly started to fill up. The water was surprisingly clear! I mean, it wasn’t perfect, but compared to what I started with, it was a massive improvement. It was actually working! I spent the rest of the day tweaking the pressure, seeing how fast I could get the water to filter. It’s a slow process, that’s for sure.

At the end of the day, I was pretty stoked. I actually managed to filter some nasty water and make it look pretty darn clean. It’s not something I’d drink just yet – I’d need to do a lot more testing and probably get some professional advice on that. But as a first go, it was a success.

I learned a ton today, and I’m excited to keep messing around with this stuff. Maybe I’ll try different types of membranes, or build a bigger filtration system. Who knows? The possibilities seem endless. It’s amazing what you can do with a little bit of curiosity and a bunch of tiny straws.