In 2011, the El Cascajo wetlands in the Huaral Province were in such a critical state of pollution that birds and fish had long abandoned the area and local authorities were losing hope of recovering the lake.
This was the starting point of an important ecological project and experiment for scientist Marino Morikawa, who decided to invest his own resources and use the help of local communities to save the wetland.
Morikawa identified two key factors which had resulted in the extreme state of the wetland: illegal landfills and the breeding of pigs, cattle and sheep. The former mayor of the region had also built a drainage canal that bordered the wetland and which had leaked into it.
The first step in recovering this wetland was to remove the invasive aquatic weed known as ‘aquatic lettuce’. This process was carried out with the help of local inhabitants, who participated in the removal of over 290 tons of aquatic lettuce; this was later used as organic compost to recover arid and desert areas for agriculture.
Morikawa then used two nanotechnology methods to remove the pollution and noxious microorganisms: the micro-nano bubbling system and a biofilter. Neither of these methods utilise artificial chemicals to decontaminate the water.
The micro-nano bubbling system consists of introducing microbubbles in the depths of the wetland, the bubbles are invisible to the human eye and their small size means they take much longer to reach the water’s surface. Thanks to this, and their natural electromagnetic properties, they can attract a great number of microorganisms, which are then trapped within them, unable to move, resulting in them being killed, or evaporated on the wetland’s surface.
Biofilters also attract noxious water bacteria in order to preserve the species which contribute to micro-flora conservation and bioremediation; these have to be adapted to the surrounding water and the specific bacteria within it.
Thanks to these two methods, the wetland was successfully decontaminated in just four months and birds and fish have now come back to inhabit El Cascajo.
Figure 1 : Before and after shots of El Cascajo
Morikawa’s current objective is to apply this method to other, much larger bodies of water such as Lake Titicaca, or to streams of water such as rivers. Both of these, because of the change in scale or because of the change from static to dynamic bodies, are uncertain in their results.
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