Biogas Production from Surplus Bioflocs Generated in Marine Shrimp Culture Using the BFT SystemAuthor: Sandro Luis da Silva Miranda (Currículo Lattes)
Advisor: Dr. Luis Henrique da Silva Poersch
Abstract
In the context of sustainable Aquaculture development, the search for new approaches to manage and treat effluents assumes a role of extreme relevance. The goal is to minimize environmental impacts and improve inputs used in the activity, through reuse or recycling. Brazil, recognized for its agricultural and aquaculture production, has considerable potential in raw materials convertible to bioenergy. This study focused on evaluating the feasibility of using effluents resulting from shrimp farming, focusing on the super-intensive cultivation of marine shrimp (Litopenaeus vannamei) through Biofloc Technology (BFT), to generate biogas through anaerobic digestion. Detailed experiments investigated the impact of shrimp farming sludge salinity on biogas composition and the effects of adding microbiological inoculum during the digestion process. Batch reactors, with completely randomized experimental design, were used. Two separate experiments were conducted with two treatments, and each treatment was replicated in triplicate. Data were subjected to statistical analyses to detect statistically significant differences between treatments. Results showed that biogas production was strongly influenced by various treatment conditions. Treatments using raw and desalinated shrimp sludge showed the highest production potentials (1.686 m³/l, 1.851 m³/l) and daily volume (0.84 L CH4/kgSV-1d-1, 0.90 L CH4/kgSV-1d-1) of methane. However, the addition of microbiological inoculum had a negative impact, possibly due to microbial competition and imbalance between carbon and nitrogen. Chromatographic analysis confirmed the predominance of methane (CH4) between 37.05% and 42.40%, validated by combustion testing indicating a minimum of 50% methane in the biogas. These findings reinforce the feasibility of converting shrimp farming waste into methane gas. Additionally, the study highlights the potential of shrimp sludge generated by Biofloc Technology (BFT) in biogas production. This approach helps produce clean energy, maintain production sustainability, and control waste, reducing environmental impact. These discoveries are significant for advancements in sustainable shrimp farming, in line with global environmental protection.