Tapping the Power of Wastewater in Low-Income Countries

Over 1000 people from 84 countries registered for the recent webinar on thermal and chemical energy recovery from wastewater. More than 50% of attendees were young water professionals. Over 100 questions were raised and discussed in a lively exchange of experiences and expectations between scientists, practitioners and students. Case studies from Denmark and Finland were presented to uncover new and emerging technologies for wastewater treatment, from heat-pumps to anaerobic digestion and incineration. These promising case studies show that there is an enormous potential in the treatment of wastewater, which can be a precious source of energy and revenue.

The webinar’s main goal was to provide food for thought on how resource recovery could contribute to facilitate the adoption of wastewater treatment in regions where wastewater is still discharged untreated into surface waters. This way, what can be considered as a precious resource, becomes a dangerous pollutant.  Untreated wastewater is not only a missed opportunity, but also a real threat to human health, biodiversity and aquatic life in rivers, lakes and oceans.

In March 2021, the UN Environment Programme, the African Development Bank and Grid Arendal presented the result of a multi-annual joint effort: The Sanitation and Wastewater Atlas of Africa.

The report emphasises that 750 million people, 69% of the total population in Africa, do not even have access to basic sanitation services. Achievement of SDG 6, halving the number of people without access to basic sanitation, is not on target for Africa, except for the countries of North Africa that increased the population gaining access by 41% since 1990. Almost no progress was made in sub-Saharan Africa.

The overwhelming interest in energy recovery and the robust evidence for energy positive sewage treatment plants provided by practitioners in charge of mid-size (300,000 PE) and larger (1.200,000 PE) wastewater treatment plants in Europe may contribute to a re-assessment of the options for economically viable wastewater treatment plants in low-income countries.

Such plants could provide energy for heat and/or air-conditioning services from the treatment of wastewater of all citizens, thus generating revenue and removing the need to collect fees for purification from citizens that cannot afford them. Next steps should focus on carrying out a high number of feasibility studies in countries with a low rate of wastewater purification, regardless of the size of plants, in many fast-growing megacities such as Nairobi, Lagos, or Kigali, each with many millions of citizens in need of wastewater treatment.

However, access to sanitation and wastewater treatment are not the only, and possibly not even the most severe problems related to water in Africa. Approximately 60% of African countries suffer from scarcity and severe water stress, indicating a strong need for water safety planning and climate resilience, and also water re-use, which will be subject of the next Resource Recovery webinar scheduled for early July 2021.

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This webinar is available on demand at this link.

Ludwig Hermann

Proman Consulting, Austria