Effect of Increasing Total Solids Contents on Anaerobic Digestion of Food Waste under Mesophilic Conditions: Performance and Microbial Characteristics Analysis

Abstract

The total solids content of feedstocks affects the performances of anaerobic digestion and the change of total solids content will lead the change of microbial morphology in systems. In order to increase the efficiency of anaerobic digestion, it is necessary to understand the role of the total solids content on the behavior of the microbial communities involved in anaerobic digestion of organic matter from wet to dry technology. The performances of mesophilic anaerobic digestion of food waste with different total solids contents from 5% to 20% were compared and the microbial communities in reactors were investigated using 454 pyrosequencing technology. Three stable anaerobic digestion processes were achieved for food waste biodegradation and methane generation. Better performances mainly including volatile solids reduction and methane yield were obtained in the reactors with higher total solids content. Pyrosequencing results revealed significant shifts in bacterial community with increasing total solids contents. The proportion of phylum Chloroflexi decreased obviously with increasing total solids contents while other functional bacteria showed increasing trend. Methanosarcina absolutely dominated in archaeal communities in three reactors and the relative abundance of this group showed increasing trend with increasing total solids contents. These results revealed the effects of the total solids content on the performance parameters and the behavior of the microbial communities involved in the anaerobic digestion of food waste from wet to dry technologies.

Effects of organic loading rates on microbial communities and biogas production from water hyacinth: a case of mono‐ and co‐digestion

“…As mentioned above, Methanosarcina is mainly found in digesters with elevated levels of VFAs and high prevalence of Methanosarcina in such digesters would still lead to CH 4 production . In co‐digestion, biogas production continuously decreased until process failure was observed in stage 3, where Methanosarcina was dominant.…”

Methane potential and metagenomics of wastewater sludge and a methane‐producing landfill solid sample as microbial inocula for anaerobic digestion of food waste

“…These genera have been described previously in landfill leachate under the dominance of Methanoculleus . The abundance of Methanosaeta and Methanosarcina is regulated by the concentration of acetate . Methanosaeta possess high affinity for acetate, whereas Methanosarcina exhibit low affinity.…”

“…Particularly, in food waste digestion efforts have been made to determine the biogas microbiome and increase yields by feedstock modification and evaluating changes in microbial composition . Co‐digestion with sewage sludge or an increase in total solids (TS) content are reported to enhanced CH 4 production, whereas microwave or autoclave pretreatment generated inhibiting or hard‐to‐digest compounds as well as a less productive and diverse microbial community. All of these studies identified Methanosarcina as a typical methanogen member in food waste digestion, indicating that the acetoclastic pathway plays an important role in CH 4 generation …”

Biogas Production Using Waste Waters – Influence of Process Parameters for Test RIG at Laboratory Scale

“…According to literature [23,24], the biogas and methane production efficiency is influenced by the total solids (TS) content of the substrate used in the anaerobic digestion process. In our study the TS content of the substrates investigated is around 2% for WW1, 2.4% for WW1+CW, 3% for WW2 and 3.5 % for WW2+CW.…”