Can produce clean water with broken tires

Damaged rubber tires, which are piled up at the bottom of rivers and in garbage piles around the world, can be used to create ideal water filtration devices, US environmental experts say.

A household water purifier.(Photo: highspeakswater.com)

Yuefeng Xie, an environmental engineer at Penn State University (USA), and colleagues built a water purification device using rubber pieces from broken tires.

The most important part of today's popular water filtration systems is one or more vertical sand tubing (or anthracite). The sand in the tube is arranged so that the larger particles are on top, and the smaller ones are below. The bigger the particle, the bigger the gap between them and vice versa. Thanks to that sort of arrangement, the toxins and dirt are trapped when water, for some reason, is bounced back.

The problem with these systems, according to Yuefeng Xie, is that the gaps between the particles are blocked by mud within a few days. When going through the sand column, the water will push the big seeds down. When water is pushed back, the entire column of sand will be disturbed.

" Such systems are designed to last up to 20 years. But only if water is pushed back once will they become useless ," Xie said.

Xie and colleagues believe that if they replace sand or anthracite with small pieces of rubber, the width is between 1 and 2 mm, they can create an ideal water purifier because they have good compression. Therefore, no matter how arranged, the rubber pieces at the bottom are always the smallest pieces because the weight of the whole column presses them downwards.

Xie claims that the rubber filter works 4 times faster than current water purification products.

Xie's findings are very interesting, said Sean Moran, CEO of environmental firm Expertise Limited in the UK. However, he thinks that Xie needs to pay attention to some points: First, mud tends to " stay " in the filter. Moran thinks that compared to sand, rubber is more susceptible to mud. Second, rubber pieces from old tires can release many toxic chemicals into water, such as heavy metals.

Viet Linh