The Experts below are selected from a list of 50145 Experts worldwide ranked by ideXlab platform
Junxin Liu - One of the best experts on this subject based on the ideXlab platform.
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thermophilic biofilter for so2 removal performance and Microbial Characteristics
Bioresource Technology, 2015Co-Authors: Jingying Zhang, Junxin LiuAbstract:Abstract A bench-scale thermophilic biofilter was applied to remove SO 2 at 60 °C in the present study. The SO 2 concentration in the inlet stream ranged from 100 mg/m 3 to 200 mg/m 3 . An average SO 2 removal efficiency of 93.10% was achieved after developing acclimated organisms that can degrade SO 2 . The thermophilic biofilter effectively reduced SO 2 , with a maximum elimination capacity of 50.67 g/m 3 /h at a loading rate of 51.44 g/m 3 /h. Removal efficiency of the thermophilic biofilter was largely influenced by the water containing rate of the packing materials. The SO 2 transfer in the biofilter included adsorption by the packing materials, dissolution in liquid, and Microbial degradation. The main product of SO 2 degradation was SO 4 2− . The temporal shifts in the bacterial community that formed in the biofilter were determined through polymerase chain reaction–denaturing gradient gel electrophoresis and DNA sequence analysis. These shifts revealed a correlation between biofilter performance and bacterial community structure.
Maria Elisa Pampulha - One of the best experts on this subject based on the ideXlab platform.
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effects of long term heavy metal contamination on soil Microbial Characteristics
Journal of Bioscience and Bioengineering, 2006Co-Authors: A Oliveira, Maria Elisa PampulhaAbstract:In this study, total heavy metal content and its effects on soil microbiological Characteristics were investigated in soil samples from an area with known long-term pollution problems. The total heavy metal concentrations of contaminated soil samples were 109 and 1558 mg/kg for Hg and As, respectively. Key microbiological parameters measured included dehydrogenase activity, ATP content and number of culturable aerobic bacteria, actinomycetes, fungi and asymbiotic nitrogen-fixers. Quantitative analysis of soil Microbial populations shows a marked decrease in total culturable numbers of the different Microbial groups of the contaminated soil samples. Certain groups of soil microbes were particularly sensitive to long-term contamination (asymbiotic nitrogen-fixers and heterotrophic bacteria). Dehydrogenase activity was found to be a sensitive assay for determining the effect of heavy metals on physiologically active soil Microbial biomass and sustains the high applicability of this parameter for soil ecotoxicological testing as reported by other authors.
Jingying Zhang - One of the best experts on this subject based on the ideXlab platform.
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thermophilic biofilter for so2 removal performance and Microbial Characteristics
Bioresource Technology, 2015Co-Authors: Jingying Zhang, Junxin LiuAbstract:Abstract A bench-scale thermophilic biofilter was applied to remove SO 2 at 60 °C in the present study. The SO 2 concentration in the inlet stream ranged from 100 mg/m 3 to 200 mg/m 3 . An average SO 2 removal efficiency of 93.10% was achieved after developing acclimated organisms that can degrade SO 2 . The thermophilic biofilter effectively reduced SO 2 , with a maximum elimination capacity of 50.67 g/m 3 /h at a loading rate of 51.44 g/m 3 /h. Removal efficiency of the thermophilic biofilter was largely influenced by the water containing rate of the packing materials. The SO 2 transfer in the biofilter included adsorption by the packing materials, dissolution in liquid, and Microbial degradation. The main product of SO 2 degradation was SO 4 2− . The temporal shifts in the bacterial community that formed in the biofilter were determined through polymerase chain reaction–denaturing gradient gel electrophoresis and DNA sequence analysis. These shifts revealed a correlation between biofilter performance and bacterial community structure.
Nan Liu - One of the best experts on this subject based on the ideXlab platform.
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Re-acclimation performance and Microbial Characteristics of a thermophilic biofilter for NOx removal from flue gas.
Applied microbiology and biotechnology, 2015Co-Authors: Shihan Zhang, Han Chen, Yinfeng Xia, Jingkai Zhao, Nan LiuAbstract:Currently, a novel chemical absorption-biological reduction (CABR) integrated process, employing Fe(II)EDTA as a solvent, is being under development to reduce the cost of NOx removal from flue gas. In this work, the NO removal profile, re-acclimation performance, and Microbial Characteristics in a thermophilic biofilter were investigated at the conditions typical to CABR process. The biofilter comprised of four layers of packing material with a surface area of 1200 m2 m−3. Experimental results revealed that the biofilter could remove 95 % of the fed NO at typical flue gas conditions. As the gas residence time varied from 90 to 15 s, the NO removal efficiency decreased from 100 to 56.5 % due to the NO mass transfer limitation. The longer period of the biofilter shutdown required more time for its re-acclimation. For example, after 8-day shutdown, the biofilter was re-acclimated in 32 h. Denaturing gradient gel electrophoresis analysis of PCR-amplified product showed that Pseudomonas, a group of denitrifier, was dominant in the biofilter. Because the Pseudomonas was abundant at the bottom layer of packed-bed, the bottom layer contributed to 60–70 % of the total NO removal. In addition, Pseudomonas gradually faded away along the gas flow path from the bottom to the top of biofilter, resulting in a significant decrease in NO removal at the other three packed-bed layers. These observed results will provide the process engineering and scale-up data with respect to the biofilter operations to help advance the CABR process to pilot-scale testing.
Jie Zhang - One of the best experts on this subject based on the ideXlab platform.
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Performances and Microbial Characteristics of granular sludge for autotrophic nitrogen removal from synthetic and mainstream domestic sewage
Chemical Engineering Journal, 2018Co-Authors: Yuhai Liang, Su Qingling, Jie ZhangAbstract:Abstract The completely autotrophic nitrogen removal over nitrite (CANON) process is an important component of energy self-sufficient sewage treatment plants, and the use of aerobic granular sludge is a profitable choice for the CANON process. In this study, the performance and Microbial Characteristics of CANON granular sludge were investigated for treating synthetic and mainstream domestic sewage. The average nitrogen removal rate (NRR) was 3.22 kg N m−3 d−1 during the high-rate operating period with high MLSS (4.09 g L−1) and DO (∼1.0 mg L−1) for treating synthetic sewage. When the influent was mainstream sewage, the average NRR was 1.11 kg N m−3 d−1. The effluent nitrate concentration was very low, and nitrate build-up was not found. High-throughput pyrosequencing results indicated that, Nitrosomonas and Candidatus Brocadia were the dominant genus in ammonia oxidizing bacteria (AOB) and anaerobic AOB (AAOB), respectively. The proportions of AOB and AAOB decreased during mainstream sewage treatment, but the reactor maintained good performance. The results confirmed the feasibility of using CANON granular sludge for treating mainstream sewage.
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Reactor performance and Microbial Characteristics of CANON process with step-wise increasing of C/N ratio.
Environmental technology, 2015Co-Authors: Xiaojing Zhang, Yuhai Liang, Jie ZhangAbstract:In this study, the nitrogen removal performance and Microbial Characteristics of completely autotrophic nitrogen removal over nitrite (CANON) process was investigated with a step-wise increasing of C/N ratio (0.5, 1, 2 and 4) in a membrane bioreactor. The Microbial distribution of aerobic ammonia-oxidizing bacteria (AOB) and anaerobic AOB (AAOB) was analysed by fluorescence in situ hybridization (FISH). Results showed that the denitrification ratio rose up correspondingly with the increase of influent C/N, and nitrogen removal rate (NRR) reached the maximum when C/N was 1 due to the harmonious work of denitrification and CANON. However, NRR decreased when influent C/N was more than 2. The threshold C/N ratio of CANON process was 2.2; so the sewage with a high C/N ratio should be pretreated by combining with pre-oxidation of organics or anaerobic-energy-producing process. FISH results showed decreasing numbers of both AOB and AAOB with the addition of organics.
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Nitrogen removal and Microbial Characteristics in CANON biofilters fed with different ammonia levels.
Bioresource technology, 2014Co-Authors: Yuhai Liang, Xiaojing Zhang, Zeng Huiping, Yang Zhuo, Cui Shaoming, Jie ZhangAbstract:Abstract The nitrogen removal performance and Microbial Characteristics of four completely autotrophic nitrogen removal over nitrite (CANON) biofilters were investigated. These four reactors were simultaneously seeded from a stable CANON biofilter with a seeding ratio of 1:1, which were fed with different ammonia levels. Results suggested that with the ammonia of 200–400 mg L−1, aerobic ammonia-oxidizing bacteria (AerAOB) and anaerobic ammonia-oxidizing bacteria (AnAOB) could perform harmonious work. The bioactivity and population of the two groups of bacteria were both high, which then resulted in excellent nitrogen removal, while too low or too high ammonia would both lead to worse performance. When ammonia was too high, the bioactivity, biodiversity and population of AerAOB all decreased and then resulted in the lowest nitrogen removal. Nitrosomonas and Candidatus Brocadia were detected as predominant functional microbes in all the four reactors. Finally, strategies for treating sewage with different ammonia levels were proposed.