Use waste as a resource
9Build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation
11Make cities and human settlements inclusive, safe, resilient and sustainable
14Conserve and sustainably use the oceans, seas and marine resources for sustainable development
Approximately 740 tonnes of plastic waste are thrown out in Dar es Salaam every day. It blocks drains, contributing to devastating floods during the rainy season, and ends up in watercourses causing harm to marine life. At the same time, Tanzania has a housing deficit of some 1.
2 million units. An estimated thirty-six percent of the shortfall is concentrated in Dar es Salaam, where most people are unable to afford building materials. Plastic waste is one possible input to produce affordable construction materials to help resolve the country’s housing crisis.
Hellena Sailas is a medical laboratory technologist. As a youth activist, she often took part in beach clean-ups, where she was struck by the quantity of single-use plastics. Being aware of the implications for marine life, she started research into a solution that would divert plastic waste from the beaches.
After 10 home-based experiments, she finally developed a formula for producing blocks from LDPE and PET plastics.
Arena Recycling was founded in 2018 and now recycles between 500 and 1000 kg of plastics per week. They melt and extrude LDPE and PET plastics to produce both construction blocks and paving slabs. Their Eco-bricks consist of 80% plastic waste and 20% sand and contain neither water nor cement.
The bricks are waterproof, anti-corrosive and mould resistant. Arena Recycling has experimented to develop its own formula to melt and mix the materials, giving them the required properties to meet Tanzanian construction standards. To collect plastic waste, Arena Recycling organises campaigns for beach clean-up around marine areas, which serves the additional purpose of educating and promoting behaviour change in waste disposal.
They also purchase plastics from community collectors. Arena Recycling has partnered with Young Water Solutions Organisation, an NGO, to collaborate with the municipality and the community members of Temeke District to construct 12 pit latrines and two water tanks for 2000 students. The Tanzania Bureau of Standards is currently verifying the Eco-bricks for certification.