Anaerobic digestion has been defined as a competitive approach to facilitate the recycling of corn stalks.However,few studies have focused on the role of direct interspecies electron transfer(DIET)pathway in the acidi...Anaerobic digestion has been defined as a competitive approach to facilitate the recycling of corn stalks.However,few studies have focused on the role of direct interspecies electron transfer(DIET)pathway in the acidification stage under the addition of different particle sizes of zero-valent iron(ZVI).In this study,three types of ZVI,namely iron filings,iron powder and nanoscale iron,were investigated,respectively,to enhance its high-value conversion.Variations in volatile fatty acids(VFAs)and methane(CH4)production associated with the underlyingmechanisms were emphatically determined.Results indicated that the addition of ZVI could increase the concentration of VFAs,with the most outstanding performance observed with the use of nanoscale iron.Importantly,the conversion of propionic acid to acetic acid was driven by adding ZVI with no between-group differences in acidizing phase.Conversely,the substrate was more fully utilized when supplied with iron powder compared with other groups in methanogenic phase,thereby displaying the maximumCH4 yield with a value of 263.1 mL/(g total solids(TS)).However,adding nanoscale iron could signally shorten the digestion time(T80),saving 7 days in comparison to the group of iron powder.展开更多
基金supported by the Fundamental Research Funds for the Central Universities of China(No.B220202066)the Natural Science Foundation of Jiangsu Province(No.BK20200527)the Anhui Provincial Key Laboratory of Environmental Pollution Control and Resource Reuse(No.2021EPC05).
文摘Anaerobic digestion has been defined as a competitive approach to facilitate the recycling of corn stalks.However,few studies have focused on the role of direct interspecies electron transfer(DIET)pathway in the acidification stage under the addition of different particle sizes of zero-valent iron(ZVI).In this study,three types of ZVI,namely iron filings,iron powder and nanoscale iron,were investigated,respectively,to enhance its high-value conversion.Variations in volatile fatty acids(VFAs)and methane(CH4)production associated with the underlyingmechanisms were emphatically determined.Results indicated that the addition of ZVI could increase the concentration of VFAs,with the most outstanding performance observed with the use of nanoscale iron.Importantly,the conversion of propionic acid to acetic acid was driven by adding ZVI with no between-group differences in acidizing phase.Conversely,the substrate was more fully utilized when supplied with iron powder compared with other groups in methanogenic phase,thereby displaying the maximumCH4 yield with a value of 263.1 mL/(g total solids(TS)).However,adding nanoscale iron could signally shorten the digestion time(T80),saving 7 days in comparison to the group of iron powder.
