This is a sustainability project for the CAPSTONE course in the Creative Sustainability program at Aalto University. It has been developed in collaboration with RiverRecycle and designed by Aybars Senyildiz, Tessa Dean, Gaspard del Marmol, Maddalena Galloni, and Oona Kaunisto, with special thanks to our guide Julie-Anne Gandier.
The Problem Context
RiverRecycle cleans some of the world's most polluted rivers by collecting and utilizing plastic waste that would otherwise be unvalued. The company's machinery removes plastic from the streams. However, during the rainy season, the invasive water hyacinth (WH) species grows excessively, causing plastic waste to become entangled with the plant.
RiverRecycle begins its operations by collecting waste from rivers.
A photograph from Pasig River covered by water hyacinth
Water hyacinth challenges RiverRecycle by mixing with plastic waste in rivers, obstructing their ability to collect plastic and clogging up waterways, damaging infrastructure, and leading to loss of income.
RiverRecycle Oy seeks sustainable solutions to reduce water hyacinth proliferation's impact on collection and sorting, while also eliminating methane emissions.
We explored ways to turn this problem into an opportunity.
Water Hyacinth
Water hyacinth is an invasive species that presents a complex trade-off between preventing methane emissions and enabling plastic collection. Utilizing all parts of the plant is the most effective way to reduce organic residue in landfills.
Research Insights
Overgrowth of water hyacinth is primarily caused by agricultural nutrient runoff and pollution along rivers. Due to the lack of proper wastewater treatment infrastructure, untreated waste is dumped into streams during rainy seasons.
Water hyacinth is typically left to decompose in landfills, which contributes to climate change by releasing methane and carbon dioxide emissions. Our solution aims to prevent these emissions by capturing the carbon emitted from the plant.
Methane’s (CH4) global warming potential is 25 times higher than that of carbon dioxide (CO2) within a time span of 100 years (Wang et al. 2019).
Solution
Our goal was to reduce organic waste in landfills, so we identified three utilization solutions that benefit the economy, communities, and RiverRecycle while reducing emissions and generating value
Approach 1: Employ the community to create handwoven local products.
Approach 2: Use unused plant parts as construction materials to prevent methane emissions.
Approach 3: Utilize carbon credits to capture greenhouse gas (GHG) emissions from the previous two solutions.
The designed system for collecting, separating, and utilizing water hyacinth plants.
With our proposal, we have calculated that RiverRecycle is able to stop 3 tons of carbon dioxide and 5.5 tons of methane every week in Citarum and Pasig rivers
We drafted production processes for different uses of water hyacinth based on extensive research. Our research was based on academic papers that study how to utilize water hyacinth, as well as more informal resources that already utilize it.
Reference
Wang, Z., Zheng, F. & Xue, S. (2019). The Economic Feasibility of the Valorization of Water Hyacinth for Bioethanol Production. Sustainability, 11(905) doi:10.3390/su11030905
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