Researchers Transform Sargassum Seaweed into Eco-Friendly Building Materials
A new study has revealed that sargassum, a type of seaweed, can be repurposed into eco-friendly building materials. Researchers from the University of São Paulo have discovered that mixing this algae with ceramic clay results in lighter and more sustainable building blocks. This innovative approach addresses the growing environmental challenge posed by sargassum, which has increasingly flooded tropical beaches from Brazil to the Caribbean, creating health hazards and impacting local economies.
Sargassum has become notorious for its foul odor and toxic properties as it decomposes, releasing harmful gases such as ammonia and methane. This has led to significant repercussions for tourism, fishing, and marine ecosystems. Traditionally, large quantities of this seaweed end up in landfills, contributing to waste without any practical reuse.
João Adriano Rossignolo, a professor at the Department of Biosystems Engineering at the University of São Paulo, coordinated the recent study published in the Journal of Materials in Civil Engineering. He stated, “Normally, sargassum is collected and disposed of in landfills without any practical use. That’s why we decided to research a way to take advantage of this large amount of biomass on the beaches.”
The researchers began their investigation by thoroughly analyzing the raw materials. They blended sargassum into ceramic clay at three concentrations: 0%, 20%, and 40%. The mixtures were shaped using an extrusion process and then fired at temperatures of 800°C, 900°C, and 1,000°C (1,472°F, 1,652°F, and 1,832°F) in both traditional and microwave ovens.
After preparing the algae-infused clay samples, the team conducted tests to assess shrinkage, water absorption, porosity, density, and strength. They also performed a life cycle assessment (LCA) to compare the environmental impact of these new materials against traditional expanded clay.
Findings indicated that adding sargassum, especially at a concentration of 40%, significantly reduced the weight of the clay. However, only samples baked in microwave ovens met the necessary strength standards. This success was attributed to better densification and a refined internal structure. The LCA results were particularly promising, showing that materials made from sargassum seaweed had a lower environmental impact than conventional expanded clay.
This led researchers to conclude that microwave-sintered sargassum clay is not just viable but a smart solution to manage the seaweed influx along tropical coastlines. Using algae to produce lightweight ceramic aggregates reduces reliance on natural resources while enhancing energy efficiency.
The innovation does not stop there. The team explored additional applications for sargassum, including its use in particulate panels for furniture and construction, and as a replacement for limestone in fiber cement tiles. Rossignolo highlighted the surprising outcomes of their experiments, noting, “We were able to use 30% sargassum in the panels and replace 100% of the limestone with its ash, with results that fully comply with current standards for these products and improve the durability and mechanical properties of the materials.”
This research opens up new avenues for sustainable construction practices while addressing the environmental challenges posed by sargassum. As scientists continue to explore innovative uses for this abundant biomass, there is potential for significant impacts on both the construction industry and coastal management efforts.
