Emissions of gases during bio-conversion of agro-waste by black soldier fly larvae

This laboratory-scale study was designed to investigate the emissions of carbon dioxide (CO2), ammonia (NH3), and hydrogen sulfide (H2S) gases during the bio-conversion of agro-waste by black soldier fly larvae (BSFL) for 14 days. The study included three experimental treatments: a control group without waste and BSFL (T0, lab background), treatment 1 containing waste with BSFL (T1), and treatment 2 containing only waste (without BSFL, T2). Process efficiency was measured by waste reduction and bio-conversion rate. Gas emissions from the process were collected using the static chamber method and determined using the gas absorption method. The results in the treatment T1 showed a notable BSFL survival rate of 99.7%, indicating a favorable condition for BSFL growth. The waste reduction rate in the T1 treatment (74.3%) was approximately two times higher than that of T2 (38.7%), indicating the ability of BSFL to decompose organic wastes efficiently. The pH and moisture content of the waste were monitored throughout the 14-day trial for both T1 and T2, and similar trends were observed. Compared to T0, gas emissions from T1 and T2 were higher. Furthermore, the CO2 and H2S emissions in T1 were higher than those in T2, while NH3 levels released in T2 were relatively higher than in T1. The preliminary results presented here could be the basis of future studies on gas emission via BSFL treatment of agro-waste.