Enhancement of Taihu blue algae anaerobic digestion efficiency by natural storage

• Published in: Bioresource technology Vol. 149; pp. 359 - 366
• Main Authors: Miao, Hengfeng, Lu, Minfeng, Zhao, Mingxing, Huang, Zhenxing, Ren, Hongyan, Yan, Qun, Ruan, Wenquan
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01-12-2013; Elsevier
• Subjects: Algae; Anaerobic digestion; Anaerobic processes; Anaerobiosis; Batch Cell Culture Techniques; Biodegradation; Biofuel production; Biogas production; Biological and medical sciences; Biological treatment of sewage sludges and wastes; Biotechnology; Biotechnology - methods; Carbohydrates - isolation & purification; Cell death; Chlorophyll - metabolism; Cyanobacteria - enzymology; Cyanobacteria - metabolism; Energy; Environment and pollution; Enzymatic characterization; Fatty acids; Fatty Acids, Volatile - biosynthesis; Fermentation; Fundamental and applied biological sciences. Psychology; Industrial applications and implications. Economical aspects; Methane - biosynthesis; Microcystins; Microcystins - isolation & purification; Natural storage; Proteins - isolation & purification; Taihu blue algae; Time Factors; Walls; TAN; PHA; Biogas production; TFA; P; VFA; AMPTS; MCs; Microcystins; AD; Enzymatic characterization; ISR; Taihu blue algae; AK; TC; Pmax; Rmax; TCD; TKN; Natural storage; Chl-a; SEM; TN; λ; TP; VS; TS; Storage; Enzyme; Biogas; Alga; Anaerobic digestion; volatile solids; cumulative specific methane yield; total nitrogen; Automatic Methane Potential Test System; inoculum to substrate ratio; R(max); total ammonia nitrogen; maximum CH potential; anaerobic digestion; polyhydroxyalkanoate; CH production rate; scanning electron microscopy; thermal conductivity detector; lag phase; total phosphate; total carbon; chlorophyll a; acetate kinase; volatile fatty acids; trifluoroacetic acid; total solids; P(max); total Kjeldahl nitrogen
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2013.09.071

•Blue algae storage led to cell death, microcystins release and VS reduction.•Short-time storage as pretreatment was beneficial to blue algae methanation for AD.•AD of blue algae stored for 15d led to the highest CH4 yield of 287.6mLg−1 VS.•VS removal, VFA and enzymes variation proved higher efficiencies of stored algae AD.•AD presented significant biodegradation potential for microcystins from blue algae.
Taihu blue algae after different storage time from 0 to 60d were anaerobic fermented to evaluate their digestibility and process stability. Results showed that anaerobic digestion (AD) of blue algae under 15d natural storage led to the highest CH4 production of 287.6mLg−1 VS at inoculum substrate ratio 2.0, demonstrating 36.69% improvement comparing with that from fresh algae. Storage of blue algae led to cell death, microcystins (MCs) release and VS reduction by spontaneous fermentation. However, it also played an important role in removing algal cell wall barrier, pre-hydrolysis and pre-acidification, leading to the improvement in CH4 yield. Closer examination of volatile fatty acids (VFA) variation, VS removal rates and key enzymes change during AD proved short storage time (⩽15d) of blue algae had higher efficiencies in biodegradation and methanation. Furthermore, AD presented significant biodegradation potential for MCs released from Taihu blue algae.