Mutual Influence between Polyvinyl Chloride (Micro)Plastics and Black Soldier Fly Larvae (Hermetia illucens L.)

Abstract

Due to the expansion in the global population, there is an increase in animal protein demand and waste generation. Currently, food waste derived from supermarkets, etc., which is used to produce biogas, is collected separately and can contain (micro)plastics deriving from food packaging, imposing potential risks to the environment. A possible solution to address protein, waste and plastic concerns can potentially be achieved by rearing black soldier fly (BSF) larvae on such substrates. In this study, we investigated the effect of polyvinyl chloride (PVC) (micro)plastics on the growth, survival, and bioconversion of BSF larvae. On the other hand, the impact of the larvae on the polymer structure and degradation was also assessed. This was carried out by rearing BSF larvae on artificial food waste spiked with micro-, meso-, and macroplastics, while measuring larval growth, survival, and bioconversion parameters. The remaining plastics were collected and analysed upon changes and degradation of their polymer structure. Generally, BSF larvae were not affected in terms of growth performance (179.9–210.4 mg), survival (77.1–87.3%), and bioconversion (FCR: 4.65–5.53) by the presence of (micro)plastics in the substrates. Furthermore, the larvae were also unable to significantly alter the polymer structure of the used plastic.

Ingestion and excretion dynamics of microplastics by black soldier fly larvae and correlation with mouth opening size

“…These results are similar to those obtained in other studies investigating the growth performance of BSF larvae reared on substrates containing other microplastics (e.g. polyvinyl chloride, polyethylene or polystyrene) 13,21 . By combining results reported in literature with our results, a hypothesis can be given as to why larval growth was not affected.…”

“…In the study of Lievens et al 13 , BSF larvae were exposed to various concentrations of polyvinyl chloride (PVC) macro-, meso-, and microplastics. In general, the presence of PVC in the substrate did not affect the larval growth.…”

A Production and Fractionation Protocol for Polyvinyl Chloride Microplastics

“…The latter can be explained by the fact that sieves are given a nominal mesh size, which might deviate from their actual size. Moreover, Lievens et al (2022) proved that microplastics produced using a cryogenic approach are irregularly shaped [ 18 ]. Hence, the particle-size analysis based on laser diffraction assumes spherical particles in its optical model.…”

Genetic diversity and organic waste degrading capacity of Hermetia illucens from the evergreen forest of the Equatorial Choco lowland

“…Moreover, Lievens et al (2022) studied the survival effects and bioconversion rate of H. illucens when fed food waste streams containing micro- (<5 mm), meso- (5–25 mm), and macroplastics (>25 mm) present in food packaging material (polyvinyl chloride (PVC)). In contrast to our results, using a different type of plastic, their study showed a complete larval cycle and relatively larger larvae than the control.…”

“…H. illucens is one of the most studied insects because of its capacity to convert a wide range of organic wastes. Nevertheless, numerous parameters affect growth performance, complicating comparisons with other studies ( Lievens et al, 2022 ). In the case of plastic conversion, information is still limited and further studies are required to answer multiple unanswered questions regarding plastic degradation mechanisms and bioaccumulation ( Li et al, 2021 ; Beale et al, 2022 ; Mitra & Das, 2022 ).…”