Innovative sanitation models from across the world

| Updated on: May 27, 2021
HYDERABAD, TELANGANA, 15/11/2017: The sewage treatment facility in Ameerpet, where waste water is treated before being let out into the Musi in Hyderabad. Photo: Nagara Gopal

HYDERABAD, TELANGANA, 15/11/2017: The sewage treatment facility in Ameerpet, where waste water is treated before being let out into the Musi in Hyderabad. Photo: Nagara Gopal

The ‘circular economy sanitation’ model accelerates demand for improved sanitation, leading to wider economic and environmental gains

While providing universal sanitation access to all has been recognised as United Nations’ Sustainable Development Goal (SDG) 6, handling the waste generated after the adoption of toilets remains an enduringly prevalent challenge, especially in the low- and middle-income countries (LMIC). The UN estimates that globally, 4.2 billion people or half of the world’s population live without safely managed sanitation — that is, their faecal waste remains untreated.

This is because the waste management systems in LMIC are over-burdened and lack finances for optimal operation. This serves as an imploding threat to environmental and human health. It is in this context that we discuss the non-capital-intensive circular economy solutions. These solutions not only design innovations to reduce waste, but also go beyond and highlight the under-explored potential of waste as an economically viable resource.

The circular economy for sanitation (CES) emphasises on the entire sanitation chain: manufacturing material for toilets, collection of waste, treatment of faecal sludge, and transforming this waste and sludge into products that can be used by other industries like fertiliser, fuel and clean water (see figure 1).

CES can enable a self-sustaining sanitation business model that accelerates demand for improved sanitation as well as its by-products, leading to wider economic and environmental gains. In the following paragraphs, innovative CES solutions from across the world are discussed.

Amberpet plant, Hyderabad

An exemplary example of a CES solution can be found in Hyderabad. Amberpet Waste Water Treatment Plant was built to lower pollution in the city’s Musi river. The plant treats faecal sludge and pumps the treated water back into the river. Along the process, the sludge is used to generate biogas which fuels the city’s demand for electricity.

The remaining compost is sold to the farmers (see figure 2). Other cities in India stand to gain from the CES model in Hyderabad as this business model improves management of sanitation-related waste, protects the environment, recycles waste into agriculture resources while creating employment opportunities.

Sanivation, Kenya

Sanivation is a low-cost solar technology that can transform faecal waste into briquettes (blocks of compressed fuel) that can be further used as the source of fuel for cooking or heating. Containment and adequate treatment of faecal waste save the communities from exposure to faecal pathogens and diarrhoeal diseases.

Further, Sanivation’s briquettes burn longer and generate less smoke as compared to other locally available sources like wood or charcoal. Finally, use of every tonne of these briquettes has been claimed to save 88 trees. Substantial environmental benefits when combined with the lower cost (than traditional waste treatment), makes Sanivation a sustainable CES solution.

SasiSana, Ghana

SasiSana gathers faecal waste from urban slums and uses it as an input for their unique anaerobic digestor to produce biogas, irrigation water and compost or agriculture fertiliser. The biogas is in turn used to generate electricity. The business model thrives on the revenues from the sale of electricity, organic fertiliser and irrigation water. This ensures the self-sustaining nature of the CES.

Green toilets, Kenya

The green toilet system by LIXIL corporation developed a compost-based design to treat faecal waste. The toilet automatically separates liquid and solid waste. This makes it easier for the maintenance workers to collect and transport the waste to a treatment facility. Since the system does not require water to transport waste to treatment plants, it does not rely on traditional sewage systems and circumvents any potential groundwater contamination.

The solid portion of faecal sludge is mixed with sawdust to eliminate the odour and recycle it into organic fertilisers for farms.

These business models are a testament to the distinct advantage that small and medium enterprises have in the local economy. A nuanced understanding of market failures can be the driving force to develop products that can integrate waste management by solving the unmet needs of local customers and industries.

While the above examples are a few of the many innovations embedded in CES, these also suffer from certain difficulties: financial viability, scalability, finding wider markets for the end-products and optimising waste collection services. For these businesses to overcome these issues and be replicated across other countries, the local entrepreneurs will need to build ties with global corporations and receive vehement support from the public sector.

Payal Seth is a consultant at Tata-Cornell Institute, Cornell University, Palakh Jain is an Assistant Professor at Bennett University

Published on May 27, 2021

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