Like all life on Earth, trees rely on water to survive, and almost all species draw it through an extensive and intricate system of roots. However, the roots aren’t the part of the tree that initiates the process, and the water isn’t ‘pushed’ up the tree.
A constant cycle
Incredibly, it’s the evaporation of water from tiny pores in every leaf that starts the cycle, creating a negative pressure or a vacuum within them, which then draws a ‘column’ of water upwards to replace that which has evaporated. This pressure is felt throughout the tree, which then finally replenishes the water supply from the ground. A mature evergreen can draw over 15,000 litres of water in a year from the ground in this way.
By drawing water from the ground, root systems create other benefits for the environment, including ground stability, and reducing risks of landslides, floods, and erosion in rural and urban areas. Tree roots can also act as filters to stop pollutants. Already knowing how trees are so important to help mitigate environmental disasters, scientists are now looking at how this natural process can be harnessed to solve the growing problems faced with regard to the treatment of sewage.
Renewable alternatives
Experiments in Quebec, Canada, have shown that approximately 30 million litres of wastewater per hectare per year could be successfully filtered through the roots of willow trees. Research published in the journal ‘Science of the Total Environment’ by a team at Université de Montréal in Canada and Imperial College London, shows how ‘bio-refinery’, where untreated or partially treated waste is filtered through the roots of willow trees, could be the future of sewage treatment.
Meanwhile, companies working on sewer maintenance and renewal are becoming increasingly involved in Sustainable Urban Drainage Systems (SUDS), where rainwater is collected, treated, and reused. If you require CCTV drainage surveys Kingsbury or other drainage services, you can find more information here: wilkinson-env.co.uk/drainage-services-cctv-surveys-midlands/drain-jetting/drain-jetting-kingsbury.
These innovative methods of cleaning water, with the promise of bio-refined sewage will help in the effort to preserve and protect the environment.