Materials that provide clean drinking water on World Water Day
Almost 800 million people around the world do not have access to clean drinking water. To draw attention to this problem, the United Nations christened 22 March World Water Day. In honour of this day, today we show you some new materials that can help people get access to clean drinking water all around the world.
Sometimes, water is readily available, but it is not suitable for drinking because of contamination with toxins. Researchers from the Indian Institute of Toxicology Research developed a low-cost magnetically responsive adsorbent material which can be used to remove an antibiotic cephalexin from water. The new material also helps in reducing plastic waste, as it is made from it!
Cephalexin is a widely used antibiotic. Because of this, as well as improper disposal, the antibiotic is now considered a micropollutant.
The researchers created the new material by turning PET into a magnetically responsive carbon nano-material by carbonisation and activation of the PET char under controlled conditions and magnetic modification by a simple chemical precipitation route. This newly developed low-cost magnetic nanomaterial has the adsorptive potential for cephalexin from the water. The minimal adsorbent dose of 0.4 gram per litre could remove more than half of the initial cephalexin concentration under laboratory conditions.
Heavy metal contamination
Heavy metal contamination is also dangerous for human health. Heavy metals are, for instance, cadmium, cobalt, copper, mercury, nickel, and lead, and can leak into water in various ways, such as old lead pipes or faulty oil drilling. A team of researchers at Rice University has developed a new low-cost filter material that can remove as much as 99.4 per cent of heavy metals from water.
The material, called supported-epoxidized carbon nanotubes (SENT), is made by growing carbon nanotubes onto quartz wool, which are then epoxidised them to make them active to adsorb metal ions. The researchers then discovered that vinegar reacts with the metal in solution to adsorb it from solution in a very efficient manner. The material looks like ordinary cotton.
The researchers claim that one gram of this material could get 83,000 litres of water at par with WHO standards.
3D printing filament
Activated carbon has a high adsorption level and is used for cleaning water, amongst other things. Unfortunately, this material is expensive, so researchers from University of Brescia, University of Bologna, and University of Trieste, as well as industrial equipment company Petroceramics decided to look for a low-cost alternative. To make the new material, they used solid wastes and natural polymers.
The material is made from sodium alginate (that can be extracted from seaweed and algae) and an industrial by-product called silica fume, which is produced in large quantities.
The substance can adsorb particles and droplets emitted by power plants, cars, and other polluters. The new material, which can be 3D printed, jetted, or applied in other ways, actually performs better than activated carbon in many ways. It also costs less energy to produce than activated carbon.
For more materials that provide clean drinking water, click here.