'Unique' equipment: Banana peel is dried and chopped to filter water

Filtering water with . banana peels or giant vacuum cleaners on the roofs of high-rise buildings are unique filtering devices that people are using.

The filter only allows large objects to pass through

As a rule of thumb, a filter will retain large objects to allow small objects to pass through. But recently, researchers at Pennsylvania State University (USA), led by TS. Tak-Sing Wong and Birgitt Boschitsch presided over, created a reverse filter, meaning that only large objects could pass through and retain small objects.

This type of backwash can be applied in surgery: the device will pass through the filter, while the germs will be left outside.In the image are small objects that have been retained by the filter.

In fact, this membrane filter is a liquid membrane similar to a soap bubble, except that the membrane is capable of repairing itself. When a large object (size about cm) reaches the membrane, thanks to its high volume and high speed, it will pass. After the object passes through, this bubble film will heal itself again. As for small objects, it means that the volume is also small and the speed is slow, because there is not enough energy penetrating through the membrane will be retained.

According to Dr. Tak-Sing Wong, the work has tested on some liquids that are most effective are water, glycerol, sodium dodecyl sulfate, tannic acid and polyethylene oxide, these films are stable up to 64 minutes without reinforcement. This type of backwash can be applied in surgery: the device will pass through the filter, while the germs will be left outside.

Specialized equipment for absorbing fine dust

For years, the existence of fine dust particles in the air is a problem of pollution for major cities around the world. Because in the atmosphere we breathe today, more and more pollutants are present, namely suspended particles of fine dust from plants, diesel engines, chimneys of household heating, gas. discharging cars and even from tire wear on roads, even from power lines .

Graphic of a giant vacuum cleaner capable of sucking within a radius of 300m and as high as 7km.

Not only fine dust particles have an alarm size of 2.5 ppm but even medium sized dust particles are dangerous to us. Whether walking in the city or even in the house, we breathe in them. They first enter the lungs and then into the bloodstream, leading to the risk of cardiovascular disease escalation.

Therefore, the medical community advises sensitive people to stay indoors and avoid heavy exercise during rush hours in order to limit breathing air pollution.

A Dutch start-up company, Envinity, has the initiative to place huge vacuum cleaners on the roofs of high-rise buildings in the most polluted areas such as industrial parks, airports .

These giant machines feature ionizing air to extract filter for 100% fine dust particles (less than 10 micrometers, which is responsible for about 350,000 premature deaths every year in Europe) and 95% of Super fine dust particles.

According to Envinity, in the prototype, these 8m-long giant machines have the capacity to handle 80,000 m3 of air / hour in a 300 m radius with a height of up to 7 km, they ionize the air to attract particles. fine dust does not produce ozone like conventional machines.

Water filter device with . banana peel

This banana peel water purifier can be produced without the use of toxic processes and they are much cheaper.

Surprisingly when TS. Gustavo Castro and colleagues at the Bioscience Institute of Biological Sciences in Brazil have discovered that by drying and shredding, banana peels can divide lead and copper levels in the river up to twenty times or in words. Another is extracting heavy metals from river water.

According to the researchers, banana peels have this ability because of carboxylic acids with affinity for metal ions. Although they are less effective than silica gel filters used in industry, Gustavo Castro's filters have two advantages: one can be manufactured without using rules. Malicious programs and the two are much cheaper, and can be used up to 11 times.