Wastewater is a growing threat to health and the environment, accounting for nearly as many planet-warming emissions as the aviation industry. According to the United Nations, this sector emits methane and nitrous oxide into the atmosphere, two major sources of greenhouse gases. “It is estimated that the degradation of organic matter during treatment accounts for more than 1.5% of global greenhouse gas emissions,” reveals the report ‘Wastewater: turning the problem into a solution’, published this week by the UN.
However, with the right policies, the authors say, wastewater could provide alternative energy to 500 million people and supply more than 10 times the water provided by the world’s current desalination capacity and offset more than 10% of global fertilizer use. . “There are multiple benefits to effectively collecting, treating and reusing wastewater, including new jobs and sources of income. Additional advantages would be obtained by reducing the volume of wastewater produced, “warns the investigation.
Currently, only 11% of the world’s treated wastewater is reused and around half of it globally untreated ends up in rivers, lakes and seas. Spain is one of the countries at the forefront in the reuse of this type of water and ranks fifth worldwide in terms of installed reuse capacity. It is estimated that “we already reuse more than 400 cubic hectometres a year, between 7 and 13% of the treated wastewater,” warns the Spanish Association for Desalination and Reuse (AEDyR). “We must not let the opportunity simply go down the drain: it is time to realize the promise of wastewater as an alternative source of clean water, energy, and important nutrients,” says Leticia Carvalho, lead coordinator of the Freshwater and UNEP Navy.
For this reason, the United Nations has urged during the Water Week that is being held these days in Stockholm (Sweden) to reduce the volume of wastewater and to manage it appropriately to capture the resources that can be reused safely. “They have great potential, but currently they are allowed to contaminate the ecosystems on which we depend,” denounces Carvalho.
Despite its impact on the environment, wastewater can become a climate solution, since “it can produce around five times more energy than necessary,” says the United Nations report. “Enough to provide electricity for around 500 million people a year,” he adds.
In addition, the reuse of nitrogen, phosphorous and potassium from wastewater would also help reduce reliance on synthetic fertilizers, offsetting 13.4% of the world’s demand for agricultural nutrients. In addition, there are additional resources that can be recovered from wastewater that are already benefiting various industries.
However, improving water management and reuse is a complex challenge. However, countries around the world have experience to draw on and expand, and solutions can be adapted to different socio-environmental contexts. The report highlights examples of successful wastewater management in high- and low-income countries, including the Caribbean, China, Colombia, Denmark, Egypt, Germany, India, Israel, Namibia, Senegal, Sweden, Singapore, the Solomon Islands, and Tunisia.
“We need to keep up the pressure to improve some critical underlying conditions if we want these actions to be successful,” explains Peter Harris, director of GRID-Arendal. “For that to happen, we need more effective governance and investment,” he concludes.
#Wastewater #solution #problem