Effect of micro-oxygen pretreatment on gas production characteristics of anaerobic digestion of kitchen waste

Zhen, Xiaofei; Zhang, Xiaoyan; Li, Shuaibing; Li, Mingche; Kang, Jian

doi:10.1007/s10163-020-01072-9

Cited by 11 publications

(2 citation statements)

References 32 publications

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“…However, the microbes for pretreatment were not adaptive to every substrate to improve methane production, nor was it under every oxygen content. For instance, Zhen et al (2020) stated that cumulative methane yield (CMY) of kitchen wastes did not show any improvement after the microaerobic pretreatment. It was reported by Fu et al that microaerobic pretreatment with excessive oxygen resulted in decreased methane production of corn straw ( Fu et al, 2016 ).…”

Section: Introductionmentioning

confidence: 99%

Anaerobic and Microaerobic Pretreatment for Improving Methane Production From Paper Waste in Anaerobic Digestion

Song

Cai

et al. 2021

Front. Microbiol.

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Having been generated with a tremendous amount annually, paper waste (PW) represents a large proportion in municipal solid waste (MSW) and also a potential source of renewable energy production through the application of anaerobic digestion (AD). However, the recalcitrant lignocellulosic structure poses obstacles to efficient utilization in this way. Recently, anaerobic and microaerobic pretreatment have attracted attention as approaches to overcome the obstacles of biogas production. This study was set out to present a systematic comparison and assessment of anaerobic and microaerobic pretreatment of PW with different oxygen loadings by five microbial agents: composting inoculum (CI), straw-decomposing inoculum (SI), cow manure (CM), sheep manure (SM), and digestate effluent (DE). The hints of microbial community evolution during the pretreatment and AD were tracked by 16S rRNA high-throughput sequencing. The results demonstrated that PW pretreated by DE with an oxygen loading of 15 ml/gVS showed the highest cumulative methane yield (CMY) of 343.2 ml/gVS, with a BD of 79.3%. In addition to DE, SI and SM were also regarded as outstanding microbial agents for pretreatment because of the acceleration of methane production at the early stage of AD. The microbial community analysis showed that Clostridium sensu stricto 1 and Clostridium sensu stricto 10 possessed high relative abundance after anaerobic pretreatment by SI, while Bacteroides and Macellibacteroides were enriched after microaerobic pretreatment by SM, which were all contributable to the cellulose degradation. Besides, aerobic Bacillus in SI and Acinetobacter in SM and DE probably promoted lignin degradation only under microaerobic conditions. During AD, VadinBC27, Ruminococcaceae Incertae Sedis, Clostridium sensu stricto 1, Fastidiosipila, and Caldicoprobacter were the crucial bacteria that facilitated the biodegradation of PW. By comparing the groups with same microbial agent, it could be found that changing the oxygen loading might result in the alternation between hydrogenotrophic and acetoclastic methanogens, which possibly affected the methanogenesis stage. This study not only devised a promising tactic for making full use of PW but also provided a greater understanding of the evolution of microbial community in the pretreatment and AD processes, targeting the efficient utilization of lignocellulosic biomass in full-scale applications.

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Section: Introductionmentioning

confidence: 99%

Anaerobic and Microaerobic Pretreatment for Improving Methane Production From Paper Waste in Anaerobic Digestion

Song

Cai

et al. 2021

Front. Microbiol.

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“…Some of these pretreatment options have been extensively studied, including sound cavitation [2], high-pressure homogenization [3], thermal hydrolysis [4,5], chemical pretreatment/post-treatment [6][7][8], along with combinations of these different alternatives. Other methods are more recent such as the case of aeration for degrading complex compounds and electrooxidation [9][10][11].…”

Section: Introductionmentioning

confidence: 99%

Description of a Decentralized Small Scale Digester for Treating Organic Wastes

et al. 2020

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This manuscript deals with the detailed design of a small digestion prototype intended as a commercial unit fully operational to cover the demand for decentralized treatment of wastes. These plants are highly affected by the complex nature of wastes giving rise to different operating problems that should be considered in detail. This paper describes the design and start-up strategy of a small-scale digestion plant with a volume of 8 m3 designed to operate with a hydrolysis pretreatment unit. The plant was designed to treat fruit and vegetable wastes as substrates derived from a local processing food factory. The performance of the plant during fed-batch operation was reported. The strategy of inoculating the reactor only to a third of its original volume and subsequently increasing the volume of the reactor by using the fed-batch mode was inadequate. The acid pH of the feeding substrate resulted in the application of a low organic loading rate with a volumetric variation of just 19.7 L/d. The performance of the plant was evaluated at non-steady state conditions and resulted in excessive destruction of volatile solids due to the low nitrogen content of the feeding substrate. The prototype reported a specific methane production of 232 L/kg volatile solids despite the low feeding rate supplemented.

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