UK and Canadian researchers filter municipal wastewater through willow trees

In the UK, infiltration by willow trees could be the answer to a growing waste problem, producing clean water, renewable biofuels and ‘green’ chemicals.

In Canada, Canada, six trillion liters of municipal wastewater are partially treated and released into the environment each year, while another 150 billion liters of untreated sewage are discharged straight into pristine surface waters.

Now, researchers have found a way to stem that flow: by filtering the waste through the roots of willow trees. They estimate that over 30 million liters of primary wastewater per hectare can be treated using ‘bio-refinery’ annually, based on experiments in Saint-Roch-de-l’Achigan in Quebec, Canada. The volume would be different in another country depending on the local environment.

Their results were published in the journal Science of the Total Environment by a team at Université de Montréal in Canada and Imperial College London in the UK.