Experimental Assessment of Multiple Properties of Mycelium-Based Composites with Sewage Sludge and Bagasse

Author: mycolabadmin
3/10/2025
View Source

Summary

Researchers created building materials using mushroom mycelium grown on sewage sludge and bagasse, eliminating waste while producing lightweight, eco-friendly composites. These materials showed excellent strength and thermal properties comparable to conventional highway backfill materials, but with significantly lower environmental impact. The study demonstrates that mycelium can effectively bind sewage sludge into useful construction materials, offering a practical solution for waste management and sustainable building.

Background

Mycelium-based composites (MBCs) are lightweight, biodegradable materials with low environmental footprint that show potential for construction applications. Sewage sludge (SS) is a cellulose-rich by-product from wastewater treatment that could serve as a sustainable substrate for MBC production, offering an alternative to conventional lightweight backfill materials that consume large amounts of cement and expanded polystyrene.

Objective

This study examined the feasibility of producing mycelium-based composites using sewage sludge and bagasse as nutrient substrates cultivated on ready-made Pleurotus ostreatus mycelium. The researchers evaluated physico-mechanical properties, morphological characteristics, and thermal stability to assess potential use as lightweight backfill materials for highway applications.

Results

Both substrates promoted fungal growth by day 10, with sewage sludge supporting more robust hyphal development. The optimal ratio of mycelium to sewage sludge was 2:1, achieving compressive strength of 690.20 kPa and density of 395-446 kg/m³. Thermal conductivity values were 0.12 Wm⁻¹K⁻¹ for bagasse-based and 0.13 Wm⁻¹K⁻¹ for sewage sludge-based composites, meeting highway backfill material requirements. Sewage sludge-based composites demonstrated superior thermal stability and higher residual mass compared to bagasse alternatives.

Conclusion

This is the first study demonstrating the successful production of mycelium-based composites using sewage sludge, confirming biological compatibility and superior mechanical properties compared to traditional substrates. The resulting biocomposites meet performance requirements for lightweight highway backfill materials while providing environmental benefits through low-carbon disposal of sewage sludge, though further optimization and investigation of the mechanism promoting mycelial growth is recommended.

Published in:Materials (Basel),
Study Type:Experimental Study,
Source: 10.3390/ma18061225; PMID: 40141510