There might be a new and improved manner to rid polluted grunge of toxins and pollutants : zap it with lasers .
By directly breaking down pollutants , researchers say , high - powered lasers can now be more effective and cheaper than conventional decontamination techniques .
The EPA estimates that there are more than half a million contaminated internet site across the United States , sham millions of demesne of land .
The number of foul sites changes oft as sites are freshly contaminated via release or natural disasters such as hurricane , while others are discovered , document , and cleaned up . As of 2013,EPA describe tracking more than 530,000 sites and nearly 23 million acres nationwide . land site are categorise in a variety of ways , often based on the level and case of contamination and the regulation under which they are supervise and clean up . ”
clean up these polluted web site can be extremely complicated , life-threatening and expensive using traditional methods .
“ Other methods are either costly , parturiency intensive , have humble efficiency , or take a foresightful metre , ” said Ming Su , an associate professor of chemical engineer at Northeastern University . With two of his graduate student , Wenjun Zheng and Sichao Hou , he has register how such a optical maser system could work , describing the validation - of - principleresults this week in the Journal of Applied Physics , from AIP Publishing .
The bighearted reward of lasers , Su excuse , is that they can be used at the site of decontamination . Many schematic decontamination methods require digging up polluted territory , drag it somewhere else to be cleaned , and then returning it — a process that is expensive and time - consuming .
These method also have shortcomings in how well they can decontaminate . One of the most popular methods uses water or constituent solvents to launder away the pollutant . But oftentimes , washing does n’t eradicate contaminants ; it only stretch them . And even if the grease is clean , you might be left with another problem in contaminated water : The organic dissolver can themselves be harmful to people , and the operation can create byproducts that become subaltern contaminants .
There are ways to decontaminate grime on - land site , but they have their own restriction . Soil vapor origin , in which air is pump into the ground to take volatile organic compound , only cultivate on permeable or homogenous ground .
biologic approaches to break down pollutant using plants or microbes are irksome , and only work for low concentrations of sure contaminants . If an area is too polluted , often nothing can be develop there at all .
Zap Dangerous Chemical Contaminates Away With Lasers, Safely
optical maser , however , can be used on - land site to wholly break down contaminants . “ There is no other method acting that can do it at such in high spirits efficiency , ” Su said .
To demonstrate that the novel method is feasible , the researchers test it on a fake dirt made from porous silica . They contaminated their artificial soil with a carcinogenic chemical call off DDE , which is a Cartesian product of DDT , the carcinogenic pesticide that was banned in the U.S. in 1972 . The DDE molecules fluoresce under ultraviolet light , making them easier to detect .
Almost immediately after radiate a luxuriously - powered infrared laser on the polluted artificial soil , the glowing ceased . The want of fluorescence indicate that the DDE was no longer present .
To remove the harmful kernel , the optical maser light heats up the pollutant locally , reach out temperatures of one thousand of arcdegree Celsius . This heat is sufficient to breach the chemical substance bonds of the pollutant , fragmenting DDE into smaller , safer molecules such as carbon paper dioxide and water .
In rule , lasers should be able to puzzle out on all types of contaminants , from constitutive compound to metallic element ions . But first , Su said , the research worker will have to do more experiment with other contaminants . succeeding discipline also ask to require more careful analysis to set whether all of the contamination is , in fact , broken down sufficiently to run into criterion .
Eventually , Su envisions a multi - laser system carry on the back of a truck . The laser Light Within , channeled through roughage - oculus transmission line that penetrate the dirt , could perhaps couple on to a plow that loosens the grime , better exposing it to the optical maser light .
Alternatives To Lasers
While we are hold off for the maturation of “ laser trucks , ” there are still other way to make a remarkable dispute with polluted or contaminated filth .
If you are worried about your own soil , regard adding compost . The EPA has found in retell visitation thatcompost can successfully remediate extremely contaminated soils . They report that “ compost , more than any other soil cleanup technique , results in an enriched soil end - production and fix the ground to a better condition than before it was contaminated . ”
TheEPA was able to successfully clean up soilcontaminated with pesticide , explosive and even backbreaking metals by treating the soil with compost .
Learn more about compost .
