Denitrification performance evaluation and kinetics analysis with mariculture solid wastes (MSW) derived carbon source in marine recirculating aquaculture systems (RAS)

• Published in: Bioresource technology 2020-10, Vol.313, p.123649-123649, Article 123649
• Main Authors: Gao, Yedong, Guo, Liang, Shao, Mengyu, Hu, Fawen, Wang, Guangce, Zhao, Yangguo, Gao, Mengchun, Jin, Chunji, She, Zonglian
• Format: Article
• Language: English
• Subjects: acidification; biodegradability; carbon; chemical oxygen demand; denitrification; Denitrification kinetics; fermentation; mariculture; Mariculture solid wastes (MSW); nitrates; NO3−-N removal efficiency (NRE); Recirculating aquaculture systems (RAS); rhamnolipids; The most readily biodegradable organics (SS)
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2020.123649

[Display omitted] •MSW were used to prepare carbon sources for denitrification in marine RAS.•The highest VFAs yield was obtained from TB treated MSW after acidification.•TB and RL treated MSW acidogenic fermentation effluents showed high DE and DR.•NO2−-N accumulation was affected by type of MSW acidogenic fermentation effluents.•The superiority of MSW carbon source was evaluated by kinetics analysis. Biological denitrification using mariculture solid wastes (MSW) carbon source is a promising solution for removing nitrate (NO3−-N) and disposing MSW in marine recirculating aquaculture systems (RAS). To enhance denitrification performance, heating (HT), rhamnolipid (RL), alkali (AL), thermophilic bacteria (TB) pre-treated MSW acidogenic fermentation effluents were prepared as carbon sources. Profiles of soluble organics in four types of fermentation effluents were first evaluated. The highest volatile fatty acids (VFAs) yield (52.1%) was obtained from TB treated MSW after acidification. RL and TB treated MSW acidogenic fermentation effluents showed high NO3−-N removal efficiency (NRE) (around 97%). Acidogenic fermentation effluent from TB treated MSW presented a high biodegradability, with the minimum effluent chemical oxygen demand (COD) amount (35 mg/L). Denitrification kinetics parameters were also analyzed; high fraction (74.5%) of the most readily biodegradable organics (SS) demonstrated that TB treated MSW acidogenic fermentation effluent is a high-quality carbon source for enhancing denitrification.