The researchers, who were funded by the Sao Paulo Research Foundation, were looking for an inexpensive, non-toxic means of treating metals in wastewater. Silica is one material with a lot of promise because of its efficiency as a metal collector, but in order to function it has to be modded out with expensive toxic chemicals. In contrast, banana peels are efficient metal collectors in their natural state. The researchers also found that the same batch of minced peels can function effectively up to eleven times, without losing its ability to bind to metals.
Coconut fibers and peanut shells have also been identified as natural metal collectors with a lot of potential. It’s all part of the green chemistry movement, which seeks to replace conventional chemicals with safer, more sustainable ones. Some other examples are vitamin b12 and potassium lactate, a milk derivative. These are being developed as a means of removing volatile organic compounds from soil.
Another aspect of the green chemistry movement is the development of more sustainable water treatment equipment, like the new generation of nanoengineered ceramic water filters. New processes like ultraviolet light and ultrasound will also come into play, though ideally the energy needed to power this equipment would have to come from a sustainable source.
Source: Clean Technica (http://s.tt/12vtN)