scholarly journals Effect of Thermal Hydrolysis Pretreatment on Anaerobic Digestion of Protein-Rich Biowaste: Process Performance and Microbial Community Structures Shift

2022 ◽  
Vol 9 ◽  
Author(s):  
Jingyang Shi ◽  
Guangyi Zhang ◽  
Hang Zhang ◽  
Fa Qiao ◽  
Jie Fan ◽  
...  
Keyword(s):  
Microbial Community ◽  
Anaerobic Digestion ◽  
Ammonia Nitrogen ◽  
Organic Load ◽  
Adaptation Period ◽  
Thermal Hydrolysis ◽  
Community Structures ◽  
Microbial Community Structures ◽  
The Difference ◽  
Protein Rich

To reveal the effects of thermal hydrolysis (TH) pretreatment (THPT) on anaerobic digestion (AD) of protein-rich substrates, discarded tofu was chosen as the object, and its batch AD tests of tofu before and after being subjected to TH at gradually increasing organic loads were carried out and the AD process characteristics were compared; furthermore, its continuous AD tests without and with THPT were also conducted and the difference of the microbial community structures was investigated. The results showed that, during AD of protein-rich tofu with increase in the organic load, inhibition from severe acidification prior to accumulation of ammonia nitrogen (AN) occurred. THPT helped overcome the acidification inhibition present in batch AD of tofu at such a high TS content of 3.6%, to obtain the maximum methane yield rate of 589.39 ml·(gVS)−1. Continuous AD of protein-rich tofu heavily depended on ammonia-tolerant hydrogenotrophic methanogens and bacteria. The continuous AD processes acclimated by HT substrates seemed to be resistant to severe organic loads, by boosting growth of ammonia-tolerant microorganisms, above all methylotrophic methanogens such as the genera RumEnM2 and methanomassiliicoccus. The process response of continuous AD of HT tofu was hysteretic, suggesting that a sufficiently long adaptation period was required for stabilizing the AD system.

Formation and succession of microbial community structure in different ecological niches under reclaimed water acclimation

2020 ◽  
Author(s):  
Jie Li ◽  
Yujiao Sun ◽  
Xiaoyu Wang ◽  
Meng Yin ◽  
Shangwei Xu
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Water Resources ◽  
Natural Water ◽  
Reclaimed Water ◽  
Ecological Niches ◽  
Community Structures ◽  
Significant Difference ◽  
Microbial Community Structures ◽  
The Difference

<p>Using reclaimed water as a resource for landscape water replenishment may alleviate the major problems of water resource shortages and water environment pollution. However, the safety of the water and the risk of eutrophication remain doubted by the public. Our study aimed to reveal the difference between natural water and reclaimed water and to discuss the rationality of reclaimed water replenishment from the perspective of microorganisms. We analyzed the microbial community structures in natural water, reclaimed water and natural biofilms and the community succession was clarified along the ecological niches, water resources, liquidity and time using 16S rRNA gene amplicon sequencing. Primary biofilms without the original community were added to study the formation of microbial community structures under reclaimed water acclimation. The results showed that the difference caused by ecological niches was more than those caused by the liquidity of water and different water resources. No significant difference was found in the microbial diversity and community structure caused by the addition of reclaimed water. Based on the microbial analysis, reclaimed water replenishment is a feasible solution that can be used for supplying river water. Innovatively, we introduced the study of biofilms and determined that the monitoring of biofilms or sediments closely related to water was also important for the early warning of water bloom, providing a unique perspective for the management of eutrophication.</p>

scholarly journals Relationship between microbial community structures and degradation efficiencies in biological contact process on domestic sewage

2021 ◽  
Vol 261 ◽  
pp. 04004
Author(s):  
Husseini Sulemana ◽  
Emmanuel Nkudede ◽  
Bo Zhang ◽  
Anthony Adebayiga Kosiba ◽  
Zaina Omary Mochiwa
Keyword(s):  
Microbial Community ◽  
Total Phosphorus ◽  
Contact Process ◽  
Ammonia Nitrogen ◽  
Domestic Sewage ◽  
Small Scale ◽  
Community Structures ◽  
Hydraulic Residence Time ◽  
Biofilm Reactors ◽  
Microbial Community Structures

In order to ascertain the characteristics of two different biofilm reactors and its efficiency, the influence of pH, DO and HRT in the clean-up of COD, NH3-N and TP as well as determining the relationship between microbial community structures and its performance of the two biofilm reactors. This study made use of a biological contact oxidation process system in a small-scale experiment to treat domestic sewage. This contemporary study examined the performance of two different fillers thus, BCF and MBBF in removal of organic pollutants from domestic wastewater as a novel technique of BCOP for sewage treatment. Two self-made biological contact biofilm reactors were used for the experiment: BCR (mounted with BCF) and MBBR (mounted with MBBF). After the biological treatment, the COD concentration of effluent could stay below 350 mg/L. The study analyzed the effects of hydraulic residence time (HRT) on COD, ammonia nitrogen (NH3-N), and total phosphorus (TP) as well as the characteristics of each biofilm filler. The optimal HRT was 12 h; at that time, the experimental results indicated that BCF had higher removal efficiency of chemical oxygen demand, ammonia-nitrogen and total phosphorus at 50%, 96%, and 86%, respectively. Great contribution was made by the process by means of improving the biodegradability of domestic sewage and reducing sludge emergence via fermentation in the biological reactor.

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