Mycelium Krathongs Turn Thailand Festival Pollution into Riparian Restoration
- Marc Violo
- 2 days ago
- 2 min read
Each November, millions of krathongs—delicate lotus-shaped offerings—are floated down rivers across Thailand as part of the Loy Krathong Festival. But beneath their beauty lies a growing problem. Modern krathongs, once made from banana leaves, are now often crafted with Styrofoam and plastic. These materials clog waterways, disrupt aquatic life, and leave behind non-degradable waste.
A new study led by researchers at Mahidol University offers an elegant fix: krathongs made from from a mycelium composite.
Biodegradable, Buoyant, and Bursting with Life
The team developed mycelium-based krathongs (MBKs) using Pleurotus pulmonarius—a widely cultivated edible mushroom in Thailand—grown on waste sawdust and ground water hyacinth, an invasive aquatic plant. These materials are not only abundant and underused but also ideal substrates for rapid mycelial colonisations.
Two formulations were tested: one with a 50:50 sawdust-to-hyacinth mix and another with 80:20. The 50:50 composite proved lighter (0.30 g/cm³), more porous, and faster to degrade—ideal for quick post-festival breakdown. It also supported faster seed germination, with morning glory (Ipomoea aquatica) seeds sprouting within two days of soil transfer and achieving a 92% germination rates.
The 80:20 mix offered greater structural strength and hydrophobicity, making it better suited for prolonged floatation in fast-moving waters.
From Ritual Offering to Living Restoration
What sets this research apart is its closed-loop design. Each MBK was embedded with viable plant seeds. Once the festival ends, the krathongs are collected, composted, and transferred to soil—where they sprout new vegetation. The process was successfully demonstrated at the 2024 Loy Krathong Sai Festival in Tak, where the Royal Forest Department oversaw post-event composting and reforestations.
The krathongs act as both spiritual offerings and ecological agents. Their degradation nourishes the soil, their structure supports plant roots, and their embedded seeds grow into new riparian plants.
A Model for Sustainable Festival Design
By valorising sawdust and water hyacinth—both environmental nuisances—the MBKs align with circular economy principles and offer a locally-adapted, low-cost solution to festival waste. The use of P. pulmonarius provides added resilience: this strain thrives in Thailand’s tropical climate and degrades lignocellulosic waste efficiently.
While challenges remain around scaling production and tailoring MBKs to different water conditions, the study points to wider applications—from eco-packaging to floating gardens.
For now, it’s a compelling vision: transforming a pollution-prone tradition into a ritual of regeneration.
