The Experts below are selected from a list of 16113 Experts worldwide ranked by ideXlab platform

Tong Zhang - One of the best experts on this subject based on the ideXlab platform.

  • metagenomic analysis of Sludge from full scale anaerobic digesters operated in municipal wastewater treatment plants
    Applied Microbiology and Biotechnology, 2014
    Co-Authors: Ying Yang, Ke Yu, Daniel T W Tang, Wing Cheong Fung, Herbert H P Fang, Tong Zhang
    Abstract:

    This study applied Illumina high-throughput se- quencing to explore the microbial communities and functions in anaerobic Digestion Sludge (ADS) from two wastewater treatment plants based on a metagenomic view. Taxonomic analysis using SILVA SSU database indicated that Proteobacteria (9.52-13.50 %), Bacteroidetes (7.18 %- 10.65 %) and Firmicutes (7.53 %-9.46 %) were the most abundant phyla in the ADS. Differences of microbial commu- nities between the two types of ADS were identified. Genera of Methanosaeta and Methanosarcina were the major methanogens. Functional analysis by SEED subsystems showed that the basic metabolic functions of metagenomes in the four ADS samples had no significant difference among them, but they were different from other microbial communi- ties from activated Sludge, human faeces, ocean and soil. Abundances of genes in methanogenesis pathway were also quantified using a methanogenesis genes database extracted from KEGG. Results showed that acetotrophic was the major methanogenic pathway in the anaerobic Sludge Digestion.

  • bacterial communities in different sections of a municipal wastewater treatment plant revealed by 16s rdna 454 pyrosequencing
    Applied Microbiology and Biotechnology, 2013
    Co-Authors: Tong Zhang
    Abstract:

    In this study, we successfully demonstrated that 454 pyrosequencing was a powerful approach for investigating the bacterial communities in the activated Sludge, Digestion Sludge, influent, and effluent samples of a full scale wastewater treatment plant treating saline sewage. For each sample, 18,808 effective sequences were selected and utilized to do the bacterial diversity and abundance analysis. In total, 2,455, 794, 1,667, and 1,932 operational taxonomic units were obtained at 3 % distance cutoff in the activated Sludge, Digestion Sludge, influent, and effluent samples, respectively. The corresponding most dominant classes in the four samples are Alphaproteobacteria, Thermotogae, Deltaproteobacteria, and Gammaproteobacteria. About 67 % sequences in the Digestion Sludge sample were found to be affiliated with the Thermotogales order. Also, these sequences were assigned into a recently proposed genus Kosmotoga by the Ribosomal Database Project classifier. In the effluent sample, we found high abundance of Mycobacterium and Vibrio, which are genera containing pathogenic bacteria. Moreover, in this study, we proposed a method to differentiate the “gene percentage” and “cell percentage” by using Ribosomal RNA Operon Copy Number Database.

  • bacterial communities in different sections of a municipal wastewater treatment plant revealed by 16s rdna 454 pyrosequencing
    Applied Microbiology and Biotechnology, 2013
    Co-Authors: Tong Zhang
    Abstract:

    In this study, we successfully demonstrated that 454 pyrosequencing was a powerful approach for investi- gating the bacterial communities in the activated Sludge, Digestion Sludge, influent, and effluent samples of a full scale wastewater treatment plant treating saline sewage. For each sample, 18,808 effective sequences were selected and utilized to do the bacterial diversity and abundance analysis. In total, 2,455, 794, 1,667, and 1,932 operational taxonomic units were obtained at 3 % distance cutoff in the activated Sludge, Digestion Sludge, influent, and effluent samples, respectively. The corresponding most dominant classes in the four samples are Alphaproteobacteria, Ther- motogae, Deltaproteobacteria, and Gammaproteobacteria. About 67 % sequences in the Digestion Sludge sample were found to be affiliated with the Thermotogales order. Also, these sequences were assigned into a recently proposed genus Kosmotoga by the Ribosomal Database Project clas- sifier. In the effluent sample, we found high abundance of Mycobacterium and Vibrio, which are genera containing pathogenic bacteria. Moreover, in this study, we proposed a method to differentiate the "gene percentage" and "cell per- centage" by using Ribosomal RNA Operon Copy Number

Xie Quan - One of the best experts on this subject based on the ideXlab platform.

  • adding granular activated carbon into anaerobic Sludge Digestion to promote methane production and Sludge decomposition
    Journal of Cleaner Production, 2017
    Co-Authors: Yafei Yang, Zhiqiang Zhao, Yaobin Zhang, Xie Quan, Zeyu Li, Zisheng Zhao
    Abstract:

    Abstract Anaerobic Digestion of waste activated Sludge is frequently restricted with the slow fermentation rate due to its complex components. Carbon materials have been reported to enhance syntrophic metabolism of anaerobic wastewater treatment, but its function in anaerobic Digestion of Sludge has yet to be investigated. In this study granular activated carbon (GAC) was added into a batch-mode anaerobic Sludge Digestion reactor with an attempt to improve the Sludge Digestion. The results showed that with adding GAC from 0 to 5.0 g, the methane production increased by 17.4%, and the Sludge reduction rate increased by 6.1 percent points (from 39.1% to 45.2%). In the 20 days’ Digestion, GAC obviously enriched hydrogen-utilizing methanogens, Geobacter, and other methanogens capable of direct interspecies electron transfer, which could enhance the electron exchange between syntrophs and methanogens to accelerate substrate consumption and methane production.

  • evaluation on direct interspecies electron transfer in anaerobic Sludge Digestion of microbial electrolysis cell
    Bioresource Technology, 2016
    Co-Authors: Zisheng Zhao, Yaobin Zhang, Xie Quan, Huimin Zhao
    Abstract:

    Increase of methanogenesis in methane-producing microbial electrolysis cells (MECs) is frequently believed as a result of cathodic reduction of CO2. Recent studies indicated that this electromethanogenesis only accounted for a little part of methane production during anaerobic Sludge Digestion. Instead, direct interspecies electron transfer (DIET) possibly plays an important role in methane production. In this study, anaerobic Digestion of Sludge were investigated in a single-chamber MEC reactor, a carbon-felt supplemented reactor and a common anaerobic reactor to evaluate the effects of DIET on the Sludge Digestion. The results showed that adding carbon felt into the reactor increased 12.9% of methane production and 17.2% of Sludge reduction. Imposing a voltage on the carbon felt further improved the Digestion. Current calculation showed that the cathodic reduction only contributed to 27.5% of increased methane production. Microbial analysis indicated that DIET played an important role in the anaerobic Sludge Digestion in the MEC.

  • potential for direct interspecies electron transfer in an electric anaerobic system to increase methane production from Sludge Digestion
    Scientific Reports, 2015
    Co-Authors: Zhiqiang Zhao, Liying Wang, Yaobin Zhang, Xie Quan
    Abstract:

    Direct interspecies electron transfer (DIET) between Geobacter species and Methanosaeta species is an alternative to interspecies hydrogen transfer (IHT) in anaerobic digester, which however has not been established in anaerobic Sludge Digestion as well as in bioelectrochemical systems yet. In this study, it was found that over 50% of methane production of an electric-anaerobic Sludge digester was resulted from unknown pathway. Pyrosequencing analysis revealed that Geobacter species were significantly enriched with electrodes. Fluorescence in situ hybridization (FISH) further confirmed that the dominant Geobacter species enriched belonged to Geobacter metallireducens. Together with Methanosaeta species prevailing in the microbial communities, the direct electron exchange between Geobacter species and Methanosaeta species might be an important reason for the “unknown” increase of methane production. Conductivity of the Sludge in this electric-anaerobic digester was about 30% higher than that of the Sludge in a control digester without electrodes. This study not only revealed for the first time that DIET might be the important mechanism on the methanogenesis of bioelectrochemical system, but also provided a new method to enhance DIET by means of bioelectric enrichment of Geobacter species.

  • enhanced anaerobic Digestion of waste activated Sludge Digestion by the addition of zero valent iron
    Water Research, 2014
    Co-Authors: Yinghong Feng, Yaobin Zhang, Xie Quan, Suo Chen
    Abstract:

    Abstract Anaerobic Digestion is promising technology to recover energy from waste activated Sludge. However, the Sludge Digestion is limited by its low efficiency of hydrolysis–acidification. Zero valent iron (ZVI) as a reducing material is expected to enhance anaerobic process including the hydrolysis–acidification process. Considering that, ZVI was added into an anaerobic Sludge Digestion system to accelerate the Sludge Digestion in this study. The results indicated that ZVI effectively enhanced the decomposition of protein and cellulose, the two main components of the Sludge. Compared to the control test without ZVI, the degradation of protein increased 21.9% and the volatile fatty acids production increased 37.3% with adding ZVI. More acetate and less propionate are found during the hydrolysis–acidification with ZVI. The activities of several key enzymes in the hydrolysis and acidification increased 0.6–1 time. ZVI made the methane production raise 43.5% and Sludge reduction ratio increase 12.2 percent points. Fluorescence in situ hybridization analysis showed that the abundances of hydrogen-consuming microorganisms including homoacetogens and hydrogenotrophic methanogens with ZVI were higher than the control, which reduced the H2 accumulation to create a beneficial condition for the Sludge Digestion in thermodynamics.

Yaobin Zhang - One of the best experts on this subject based on the ideXlab platform.

  • adding granular activated carbon into anaerobic Sludge Digestion to promote methane production and Sludge decomposition
    Journal of Cleaner Production, 2017
    Co-Authors: Yafei Yang, Zhiqiang Zhao, Yaobin Zhang, Xie Quan, Zeyu Li, Zisheng Zhao
    Abstract:

    Abstract Anaerobic Digestion of waste activated Sludge is frequently restricted with the slow fermentation rate due to its complex components. Carbon materials have been reported to enhance syntrophic metabolism of anaerobic wastewater treatment, but its function in anaerobic Digestion of Sludge has yet to be investigated. In this study granular activated carbon (GAC) was added into a batch-mode anaerobic Sludge Digestion reactor with an attempt to improve the Sludge Digestion. The results showed that with adding GAC from 0 to 5.0 g, the methane production increased by 17.4%, and the Sludge reduction rate increased by 6.1 percent points (from 39.1% to 45.2%). In the 20 days’ Digestion, GAC obviously enriched hydrogen-utilizing methanogens, Geobacter, and other methanogens capable of direct interspecies electron transfer, which could enhance the electron exchange between syntrophs and methanogens to accelerate substrate consumption and methane production.

  • evaluation on direct interspecies electron transfer in anaerobic Sludge Digestion of microbial electrolysis cell
    Bioresource Technology, 2016
    Co-Authors: Zisheng Zhao, Yaobin Zhang, Xie Quan, Huimin Zhao
    Abstract:

    Increase of methanogenesis in methane-producing microbial electrolysis cells (MECs) is frequently believed as a result of cathodic reduction of CO2. Recent studies indicated that this electromethanogenesis only accounted for a little part of methane production during anaerobic Sludge Digestion. Instead, direct interspecies electron transfer (DIET) possibly plays an important role in methane production. In this study, anaerobic Digestion of Sludge were investigated in a single-chamber MEC reactor, a carbon-felt supplemented reactor and a common anaerobic reactor to evaluate the effects of DIET on the Sludge Digestion. The results showed that adding carbon felt into the reactor increased 12.9% of methane production and 17.2% of Sludge reduction. Imposing a voltage on the carbon felt further improved the Digestion. Current calculation showed that the cathodic reduction only contributed to 27.5% of increased methane production. Microbial analysis indicated that DIET played an important role in the anaerobic Sludge Digestion in the MEC.

  • potential for direct interspecies electron transfer in an electric anaerobic system to increase methane production from Sludge Digestion
    Scientific Reports, 2015
    Co-Authors: Zhiqiang Zhao, Liying Wang, Yaobin Zhang, Xie Quan
    Abstract:

    Direct interspecies electron transfer (DIET) between Geobacter species and Methanosaeta species is an alternative to interspecies hydrogen transfer (IHT) in anaerobic digester, which however has not been established in anaerobic Sludge Digestion as well as in bioelectrochemical systems yet. In this study, it was found that over 50% of methane production of an electric-anaerobic Sludge digester was resulted from unknown pathway. Pyrosequencing analysis revealed that Geobacter species were significantly enriched with electrodes. Fluorescence in situ hybridization (FISH) further confirmed that the dominant Geobacter species enriched belonged to Geobacter metallireducens. Together with Methanosaeta species prevailing in the microbial communities, the direct electron exchange between Geobacter species and Methanosaeta species might be an important reason for the “unknown” increase of methane production. Conductivity of the Sludge in this electric-anaerobic digester was about 30% higher than that of the Sludge in a control digester without electrodes. This study not only revealed for the first time that DIET might be the important mechanism on the methanogenesis of bioelectrochemical system, but also provided a new method to enhance DIET by means of bioelectric enrichment of Geobacter species.

  • enhanced anaerobic Digestion of waste activated Sludge Digestion by the addition of zero valent iron
    Water Research, 2014
    Co-Authors: Yinghong Feng, Yaobin Zhang, Xie Quan, Suo Chen
    Abstract:

    Abstract Anaerobic Digestion is promising technology to recover energy from waste activated Sludge. However, the Sludge Digestion is limited by its low efficiency of hydrolysis–acidification. Zero valent iron (ZVI) as a reducing material is expected to enhance anaerobic process including the hydrolysis–acidification process. Considering that, ZVI was added into an anaerobic Sludge Digestion system to accelerate the Sludge Digestion in this study. The results indicated that ZVI effectively enhanced the decomposition of protein and cellulose, the two main components of the Sludge. Compared to the control test without ZVI, the degradation of protein increased 21.9% and the volatile fatty acids production increased 37.3% with adding ZVI. More acetate and less propionate are found during the hydrolysis–acidification with ZVI. The activities of several key enzymes in the hydrolysis and acidification increased 0.6–1 time. ZVI made the methane production raise 43.5% and Sludge reduction ratio increase 12.2 percent points. Fluorescence in situ hybridization analysis showed that the abundances of hydrogen-consuming microorganisms including homoacetogens and hydrogenotrophic methanogens with ZVI were higher than the control, which reduced the H2 accumulation to create a beneficial condition for the Sludge Digestion in thermodynamics.

Zisheng Zhao - One of the best experts on this subject based on the ideXlab platform.

  • adding granular activated carbon into anaerobic Sludge Digestion to promote methane production and Sludge decomposition
    Journal of Cleaner Production, 2017
    Co-Authors: Yafei Yang, Zhiqiang Zhao, Yaobin Zhang, Xie Quan, Zeyu Li, Zisheng Zhao
    Abstract:

    Abstract Anaerobic Digestion of waste activated Sludge is frequently restricted with the slow fermentation rate due to its complex components. Carbon materials have been reported to enhance syntrophic metabolism of anaerobic wastewater treatment, but its function in anaerobic Digestion of Sludge has yet to be investigated. In this study granular activated carbon (GAC) was added into a batch-mode anaerobic Sludge Digestion reactor with an attempt to improve the Sludge Digestion. The results showed that with adding GAC from 0 to 5.0 g, the methane production increased by 17.4%, and the Sludge reduction rate increased by 6.1 percent points (from 39.1% to 45.2%). In the 20 days’ Digestion, GAC obviously enriched hydrogen-utilizing methanogens, Geobacter, and other methanogens capable of direct interspecies electron transfer, which could enhance the electron exchange between syntrophs and methanogens to accelerate substrate consumption and methane production.

  • evaluation on direct interspecies electron transfer in anaerobic Sludge Digestion of microbial electrolysis cell
    Bioresource Technology, 2016
    Co-Authors: Zisheng Zhao, Yaobin Zhang, Xie Quan, Huimin Zhao
    Abstract:

    Increase of methanogenesis in methane-producing microbial electrolysis cells (MECs) is frequently believed as a result of cathodic reduction of CO2. Recent studies indicated that this electromethanogenesis only accounted for a little part of methane production during anaerobic Sludge Digestion. Instead, direct interspecies electron transfer (DIET) possibly plays an important role in methane production. In this study, anaerobic Digestion of Sludge were investigated in a single-chamber MEC reactor, a carbon-felt supplemented reactor and a common anaerobic reactor to evaluate the effects of DIET on the Sludge Digestion. The results showed that adding carbon felt into the reactor increased 12.9% of methane production and 17.2% of Sludge reduction. Imposing a voltage on the carbon felt further improved the Digestion. Current calculation showed that the cathodic reduction only contributed to 27.5% of increased methane production. Microbial analysis indicated that DIET played an important role in the anaerobic Sludge Digestion in the MEC.

Yuxua Zhang - One of the best experts on this subject based on the ideXlab platform.

  • enhancement of anaerobic Sludge Digestion by high pressure homogenization
    Bioresource Technology, 2012
    Co-Authors: Sheng Zhang, Panyue Zhang, Yuxua Zhang
    Abstract:

    To improve anaerobic Sludge Digestion efficiency, the effects of high-pressure homogenization (HPH) conditions on the anaerobic Sludge Digestion were investigated. The VS and TCOD were significantly removed with the anaerobic Digestion, and the VS removal and TCOD removal increased with increasing the homogenization pressure and homogenization cycle number; correspondingly, the accumulative biogas production also increased with increasing the homogenization pressure and homogenization cycle number. The optimal homogenization pressure was 50 MPa for one homogenization cycle and 40 MPa for two homogenization cycles. The SCOD of the Sludge supernatant significantly increased with increasing the homogenization pressure and homogenization cycle number due to the Sludge disintegration. The relationship between the biogas production and the Sludge disintegration showed that the accumulative biogas and methane production were mainly enhanced by the Sludge disintegration, which accelerated the anaerobic Digestion process and improved the methane content in the biogas.