When they find their way into landfill, electronic waste like phones and computers can wreak havoc on groundwater supplies, contaminating them with toxic heavy metals like lead and mercury. Scientists at Rice University have come up with new kind of filter made from carbon nanotubes and quartz fibers claimed to cleanse water of 99 percent of these types of metals. What’s more, they can be washed out and used over and over.

The new filters use quartz fibers as a substrate and the carbon nanotubes are then grown on top of them and treated with an oxidizing agent. This final step is what gives the material its supreme metal-soaking ability, according to the researchers. Read more

Most common water purification methods rely on mechanical filters or a membrane to remove contaminants. But over time, these become clogged and need to be replaced. A new technology developed by researchers at Princeton University doesn’t require filters at all, instead relying on the injection of CO2 gas to change the water’s chemistry and separate waste particles based on their electrical charge.

A new water purification technique relies on an injection of CO2 gas into a water stream rather than filters or membranes to separate particles from water.

The system is simple and low-cost, consisting of a silicone rubber tube that is split into two channels at one end. Because silicone rubber is permeable to CO2, the pressurized gas is able to diffuse through one wall of the tube and mix with the water flowing inside. This interaction alters the chemistry of the water, making it slightly more acidic and creating charged particles, or ions.

One of these ions is a positively charged hydrogen atom, which moves quickly through the water solution, while another is a bicarbonate molecule with a negative charge that moves through the water more slowly. The movement of these molecules creates a small electric field and, because most particles suspended in the water have a charge, they are attracted to one side of the water stream, while the filtered water, which has no charge, continues in its own channel. The tube then splits in two, with the filtered water flowing through one, and the waste particles flowing through the other. Read more

Whether water has a taste of its own or is merely a flavor carrier has long divided the scientific community. Some scientists have proposed that its flavor depends on your saliva and what you were eating previously, while others have argued that it has its own, albeit undefined, taste that can be sensed by the brain. A new study by Caltech researchers could help advance this debate: according to their findings, not only does such a sense exist, but it’s located in an unexpected place.

Water has been described as “tasteless” since the time of Aristotle but a new Caltech study shows that it might actually have a taste of its own that our tongue can sense

Tastants are chemical molecules that stimulate the sensory cells in our taste buds that can detect the five basic tastes: sweetness, sourness, bitterness, saltiness and umami. For example, when we eat foods with ingredients such as cheese or tomatoes, the glutamate they contain elicits the taste known as umami. So exactly which of the five basic taste receptor cells does water stimulate – or is there a sixth that we don’t know about? Read more