Introduction

Treatment of wastewater containing biodegradable organic substances with black soldier fly larvae, with the recovery of resources from the larval biomass produced. The invention overcomes the high mortality typical of their use in a liquid environment, ensuring optimal environmental conditions for growth thus increasing treatment efficiency.

Technical features

Method for the treatment of waste waters high in organic content using black soldier fly larvae. The method consists of an innovative method of administering the wastewater, by mixing it with a solid support matrix, porous and non-biodegradable, which allows the larvae to come into contact with the liquid to be treated and move according to their needs. The larvae will then be able to immerse themselves in the liquid to feed and re-emerge to breathe. Thanks to this specific support, a favourable environment for the growth of the larvae is created, increasing the efficiency of the treatment and the production of the larval biomass. Recent studies have achieved a 90% reduction in the chemical oxygen demand (COD) of the treated liquids, going from 60,000 mg / L to 6,000 mg / L, with specific COD removal rates (mgCOD / mgVS / day) three times higher than activated sludge. Construction of a pilot plant aimed at optimising the support and process is underway (TRL 4).

Possible Applications

• Treatment of wastewater with a high organic load, e.g. discharges from the food industry (wineries, juices production, etc.);
• Circular economy – from organic waste to use of larvae as animal feed;
• Protein extraction from larval biomass;
• Extraction of lipids from larval biomass for biodiesel or lubricants.

Advantages

• Recovery of both material and energy resources from the larval biomass produced;
• Absence of aeration systems;
• Minimisation of solid waste typical of purification processes (sludge, digestate);
• Targeted treatment of the liquid substrate, minimising process residues,
• Survival rate of larvae comparable to that of treatment with solid matrices.