Lag Phase in the Anaerobic Co-Digestion of Sargassum spp. and Organic Domestic Waste

Abstract

The mass arrival of pelagic sargassum is an international issue that is currently taking its toll on the economic activity of affected regions by causing a significant reduction in investment and tourism. The purpose of this work was to evaluate the Logistic Modified and Gompertz Modified sigmoid kinetic models for describing the lag phase in the generation of biomethane. The case studies were: anaerobic co-digestion (ACoD) of Sargassum spp./domestic organic waste and Sargassum spp. in mono-digestion. The experimental method, based on biochemical methane potential (BMP), enabled kinetic models to be built for methane production under environmental conditions and an estimate to be made for the duration of the lag phase. The maximum cumulative production determined for monodigestion was 140.7 cm3 of CH4/g SV at 99 days, and for ACoD, it was 161.3 cm3 of CH4/g SV at 172 days. The lag phase was determined to be approximately 7 days and 93 days, respectively. It was concluded that the modified sigmoid growth functions are a valuable tool for studying the start-up and scaling of systems for the ACoD of organic waste. The results present the ACoD of coastal pelagic sargassum algae and domestic organic waste as a potential alternative energy source.

Co-digestion approach for enhancement of biogas production by mixture of untreated napier grass and industrial hydrolyzed food waste

“…This lag phase was observed due to the bacteria from the anaerobic sludge that treating the swine manure needing time to adapt to the new condition that was rich in organic acid and undigested materials in the first stage. This study has a similar lag phase period and in line with the previously reported study ( López-Aguilar et al, 2023 ).…”

Assessment of Leachate Generated by Sargassum spp. in the Mexican Caribe: Part 1 Spatial Variations

“…There is a difference between the decomposition of a marine and a terrestrial biomass, since they are from different environments; a marine biomass has resistance to salinity, and consequently different microbial ecosystems are involved in the stages of their degradation [45,46]. In this digestion, there is an assimilation of the main sources of proteins, carbohydrates, and fatty acids, where, in addition to generating a liquid fraction with soluble organic matter, a biogas is generated in the last phases, which is a mixture composed of CH 4 and CO 2 , and to a lesser extent H 2 S, O 2 , and H 2 [47]. The composition of the organic matter dissolved in a leachate generated by decomposition, as well as the proportions of the gases generated, may vary depending on the composition of the decomposing organic matter, rate, and microbial activity, as well as the conditions of the environment; in the case of Sargassum sp.…”