Filters

​Whether you want to add special effects to a photo, reduce haziness or color the scene, lens filters can be very useful in-the-field photography tools. The Rapid Filter System by Alter lets photographers apply a filter the moment its needed, and disengage when it's not.​

Water filters get less effective as bacteria builds up on their surface. Now, researchers at Washington University in St. Louis have developed a new type of membrane that reduces such biofouling by actively killing bacteria with graphene – and in an interesting twist, it’s built by bacteria.

​It can be a hassle, trying to remember when to change the air filter in your furnace. Even then, you may end up changing it earlier or later than is actually required. Toronto-based CleanAir.ai is now offering an alternative, with its "smart" Alvi furnace filter.

Water filters can get dirty and lose their effectiveness quickly. Now researchers have tested a new nature-inspired membrane that filters liquids using other liquids, making for a more efficient and longer-lasting membrane.

Most water filters work by a sieve principle, in which particles that are too big to pass through a filtration membrane's pores end up collecting on it. The problem is, such filters get clogged with trapped particles. The manta ray, however, has developed a work-around.

If you spend much time backcountry hiking, chances are you're the sort of person who would find use for at least two things: a trekking pole and a water purifier. Well, PurTrek combines them both in one carbon fiber-bodied device.

​Sometimes, people want to clean up polluted water, by removing spilled oil from its surface. Other times, they want to purify oil-based fuel, by removing water from it. An inexpensive new "smart" membrane created at Canada's University of British Columbia can switch between doing both.

​Chances are, you don't give a lot of thought to changing the air filter on your furnace or air conditioner. You might go check on it occasionally, or just put a reminder on the calendar. FloSmart, however, is designed to notify you when it detects that the filter needs replacing.

The most commonly-used water filtration media are silicon gels and activated carbon. These can only be used once, however. By contrast, not only can filters made with carbon nanotubes be reused, but they're also reportedly more effective at removing organic pollutants.​

There may be a new way of keeping orange and grapefruit peels out of our landfills – besides composting them, that is. Researchers have devised a method of using the peels to remove heavy metals from wastewater.

​​Oftentimes, the places that require water purification the most – such as developing nations or disaster sites – have the least in the way of infrastructure. Help could be on the way, however, in the form of water filters made from wood.​

​After the Fukushima nuclear plant accident occurred, millions of gallons of radioactive water was left over. Scientists from Texas and Russia, however, may know what to do with it. They've developed a type of carbon that can reportedly filter radionuclides from water.