Plants have numerous uses ranging from medicinal to food to garments and decoration. This further extends to use plants to solve environmental problems caused by human activities, finds a researcher at the Department of Biological Sciences at the University of Montreal.
The work of the researcher focuses on harnessing the natural ability of plants to treat wastewater. The details of two separate studies on sustainable and cost-effective technologies to harness wastewater treating ability of plants was recently published.
This work of two researchers involves creating a model to maximize the evapotranspiration potential of plants.
Earlier, the initiative involved developing an original design for a zero-liquid discharge wetland that treats industrial wastewater. The objective was to completely eliminate all the contaminated water by evapotranspiration for zero discharge into the environment.
Technically, a zero-liquid discharge wetland is a leak free artificial basin containing vegetation cultivated in soil and coarse sand. When the contaminated water flows through sand, the plants absorb water and then discharges it into the air as vapor. This causes the contaminants to be immobilized in the sand, thereby removing any danger of seeping into the environment. The plants and bacteria in the roots can also disintegrate some of the contaminants and make them less toxic.
In fact, such built wetlands have long been used to treat wastewater, in particular in Europe. The innovative part of the work is modelling to construct wetland whose parameters can be adjusted to optimize the treatment of leachate – a mixture of buried contaminants and rainwater.
The key question was to design a zero-liquid discharge wetland when the quantity of water flowing into the system is variable depending on rainfall. The solution for such a system lies in the shape of wetland, choice of vegetation, and installation of a temporary storage tank for water.