Enhancing Volatile Fatty Acid Accumulation in Seaweed-Arrested Anaerobic Digestion via a Two-Tier Framework of Engineering Diagnostics and Microbial Surveillance

Abstract

This study presents a two-tier framework for brown seaweed-arrested anaerobic digestion (SW-AAD) by coupling engineering diagnostics (tier-1) with microbial surveillance (tier-2) to transform conventional digesters into volatile fatty acid (VFAs) biorefineries. In 70-day lab-scale batch tests (volume: 2 L), engineering diagnostics revealed that sequential additions of brown seaweed elevated salinity to 3.3% ash content, stabilized pH at 5.8-6.1, collapsed the CH/CO2 ratio from 2.98 to View larger version (41K): org.highwire.dtl.DTLVardef@1dc596dorg.highwire.dtl.DTLVardef@1731cadorg.highwire.dtl.DTLVardef@5fe025org.highwire.dtl.DTLVardef@74d8d3_HPS_FORMAT_FIGEXP M_FIG C_FIG Environmental synopsisBrown seaweed-arrested anaerobic digestion (SW-AAD) leverages seaweed-driven salinity, and acidification to suppress methanogenesis, diverting >50% of carbon to VFAs (14.5 g COD L-{superscript 1}) while cutting methane by 99%. A two-tier framework couples engineering diagnostics with microbial surveillance and asynchrony-resolved analysis, enabling feedback control and low-emission waste valorization in digesters.