Effects of free ammonia on volatile fatty acid accumulation and process performance in the anaerobic digestion of two typical bio-wastes

The effect of free ammonia on volatile fatty acid （VFA） accumulation and process instability was studied using a lab-scale anaerobic digester fed by two typical bio-wastes： fruit and vegetable waste （FVW） and food waste （FW） at 35℃ with an organic loading rate （OLR） of 3.0 kg VS/（m3-day）. The inhibi...

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Bibliographic Details
Published inJournal of environmental sciences (China) Vol. 55; no. 5; pp. 49 - 57
Main Authors Shi, Xuchuan, Lin, Jia, Zuo, Jiane, Li, Peng, Li, Xiaoxia, Guo, Xianglin
Format Journal Article
LanguageEnglish
Published Netherlands Elsevier B.V 01.05.2017
Subjects
Ammonia - analysis
Ammonia inhibition
Anaerobic digestion
Anaerobiosis
Bio-wastes
Biodegradation, Environmental
Bioreactors - microbiology
Fatty Acids, Volatile - analysis
Process indicator
VFA accumulation
Waste Disposal, Fluid - methods
产甲烷菌
厌氧消化器
厌氧消化过程
挥发性脂肪酸
游离氨
生物废弃物
积累
过程性能
VFA accumulation
Ammonia inhibition
Process indicator
Anaerobic digestion
Bio-wastes
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Summary:The effect of free ammonia on volatile fatty acid （VFA） accumulation and process instability was studied using a lab-scale anaerobic digester fed by two typical bio-wastes： fruit and vegetable waste （FVW） and food waste （FW） at 35℃ with an organic loading rate （OLR） of 3.0 kg VS/（m3-day）. The inhibitory effects of free ammonia on methanogenesis were observed due to the low C/N ratio of each substrate （15.6 and 17.2, respectively）. A high concentration of free ammonia inhibited methanogenesis resulting in the accumulation of VFAs and a low methane yield. In the inhibited state, acetate accumulated more quickly than propionate and was the main type of accumulated VFA. The co-accumulation of ammonia and VFAs led to an ＂inhibited steady state＂ and the ammonia was the main inhibitory substance that triggered the process perturbation. By statistical significance test and VFA fluctuation ratio analysis, the free ammonia inhibition threshold was identified as 45 mg/L. Moreover, propionate, iso-butyrate and valerate were determined to be the three most sensitive VFA parameters that were subject to ammonia inhibition.
Bibliography:Ammonia inhibition VFA accumulation Anaerobic digestion Process indicator Bio-wastes
The effect of free ammonia on volatile fatty acid （VFA） accumulation and process instability was studied using a lab-scale anaerobic digester fed by two typical bio-wastes： fruit and vegetable waste （FVW） and food waste （FW） at 35℃ with an organic loading rate （OLR） of 3.0 kg VS/（m3-day）. The inhibitory effects of free ammonia on methanogenesis were observed due to the low C/N ratio of each substrate （15.6 and 17.2, respectively）. A high concentration of free ammonia inhibited methanogenesis resulting in the accumulation of VFAs and a low methane yield. In the inhibited state, acetate accumulated more quickly than propionate and was the main type of accumulated VFA. The co-accumulation of ammonia and VFAs led to an ＂inhibited steady state＂ and the ammonia was the main inhibitory substance that triggered the process perturbation. By statistical significance test and VFA fluctuation ratio analysis, the free ammonia inhibition threshold was identified as 45 mg/L. Moreover, propionate, iso-butyrate and valerate were determined to be the three most sensitive VFA parameters that were subject to ammonia inhibition.
11-2629/X
ObjectType-Article-1
SourceType-Scholarly Journals-1
ObjectType-Feature-2
content type line 23
ISSN:1001-0742
1878-7320
DOI:10.1016/j.jes.2016.07.006