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Min Yang - One of the best experts on this subject based on the ideXlab platform.
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dynamics of the Microfauna community in a full scale municipal wastewater treatment plant experiencing sludge bulking
European Journal of Protistology, 2013Co-Authors: Yu Zhang, Xue Bai, Haipeng Bao, Yang Wen, Min YangAbstract:We investigated the dynamics of the Microfauna community in activated sludge, with special reference to sludge bulking, in two parallel municipal wastewater treatment systems in Beijing, China over a period of 14 months. Annual cyclic changes in Microfauna community structures occurred in both systems. RELATE analysis based on Spearman's Rank correlation indicated that Microfauna community structures were highly correlated with the sludge volume index (SVI) (p<0.001), which indicates sludge settleability. Nutrient conditions of raw sewage (p<0.01) and hydraulic retention time (HRT) (p<0.05) were also related to Microfauna community structures. Abundances of the species Epistylis plicatilis and Vorticella striata increased significantly with an increase in SVI (p<0.001) and decrease in water temperature (p<0.001), suggesting that sludge bulking may have created favorable conditions for the two species, even under unfavorable temperature conditions. Sludge de-flocculation primarily due to the excessive growth of Microthrix parvicella-like filaments could be an important driving force for the Microfauna community changes. The release of flocculated non-filamentous bacteria may represent a suitable food source for these species. The two species may be considered as potential bioindicators for sludge bulking.
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dynamics of the Microfauna community in a full scale municipal wastewater treatment plant experiencing sludge bulking
European Journal of Protistology, 2013Co-Authors: Bo Hu, Yu Zhang, Rong Qi, Wei An, Muqi Xu, Jian Gu, Min YangAbstract:We investigated the dynamics of the Microfauna community in activated sludge, with special reference to sludge bulking, in two parallel municipal wastewater treatment systems in Beijing, China over a period of 14 months. Annual cyclic changes in Microfauna community structures occurred in both systems. RELATE analysis based on Spearman's Rank correlation indicated that Microfauna community structures were highly correlated with the sludge volume index (SW) (p<0.001), which indicates sludge settleability. Nutrient conditions of raw sewage (p<0.01) and hydraulic retention time (HRT) (p<0.05) were also related to Microfauna community structures. Abundances of the species Epistylis plicatilis and Vorticella striata increased significantly with an increase in SW (p<0.001) and decrease in water temperature (p<0.001), suggesting that sludge bulking may have created favorable conditions for the two species, even under unfavorable temperature conditions. Sludge de-flocculation primarily due to the excessive growth of Microthrix parvicella-like filaments could be an important driving force for the Microfauna community changes. The release of flocculated non-filamentous bacteria may represent a suitable food source for these species. The two species may be considered as potential bioindicators for sludge bulking. (C) 2013 Elsevier GmbH. All rights reserved.
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Dynamics of the Microfauna community in a full-scale municipal wastewater treatment plant experiencing sludge bulking
European journal of protistology, 2013Co-Authors: Yu Zhang, Xue Bai, Haipeng Bao, Yang Wen, Min YangAbstract:We investigated the dynamics of the Microfauna community in activated sludge, with special reference to sludge bulking, in two parallel municipal wastewater treatment systems in Beijing, China over a period of 14 months. Annual cyclic changes in Microfauna community structures occurred in both systems. RELATE analysis based on Spearman's Rank correlation indicated that Microfauna community structures were highly correlated with the sludge volume index (SVI) (p
Paul C. D. Newton - One of the best experts on this subject based on the ideXlab platform.
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Long-term changes in topsoil nematode populations in grazed pasture under elevated atmospheric carbon dioxide
Biology and Fertility of Soils, 2009Co-Authors: Gregor W. Yeates, Paul C. D. NewtonAbstract:Increasing atmospheric CO_2 concentrations are expected to affect ecosystems processes, and while a New Zealand study reported a response in soil biological activity after 4 years of CO_2 enrichment, apparently reflecting increased populations of Longidorus elongatus , similar findings have not been reported from other sites. Soil Microfauna in 0–10 cm soil under a sheep-grazed pasture on a sand was assessed quarterly in FACE rings that were either at ambient CO_2 or had been exposed to 475 μl l^−1 CO_2 for some 9 years. Although the area had been subject to a severe drought and Microfaunal populations were lower than previously found, the effects of elevated CO_2 on Microfaunal populations were broadly similar to those at 4 years. Average populations of the root-feeding L. elongatus increased from 67,000 to 233,000 m^−2 (3.48×) compared with a 4.26× increase after 4 years; microbial-feeding nematodes increased slightly, while predacious nematodes showed a 2.0× increase. A pot experiment showed an additive effect of elevated CO_2 and L. elongatus abundance in reducing specific root length. That similar effects have been found 4 and 9 years after CO_2 enrichment commenced suggests they are real, and emphasises the difference to other sites around the world where much lower responses to elevated CO_2 have been found. This, in part, reflects the unique combination of soil, plant and soil biological conditions at each site and confirms the strong effect of soil type and vegetation on soil biological processes. Just as the effects of global climate change on a given region are idiosyncratic, so it seems are the effects of elevated CO_2 on soil and ecosystem processes. In part, this reflects our limited understanding of below-ground processes.
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Long-term changes in topsoil nematode populations in grazed pasture under elevated atmospheric carbon dioxide
Biology and Fertility of Soils, 2009Co-Authors: Gregor W. Yeates, Paul C. D. NewtonAbstract:Increasing atmospheric CO_2 concentrations are expected to affect ecosystems processes, and while a New Zealand study reported a response in soil biological activity after 4 years of CO_2 enrichment, apparently reflecting increased populations of Longidorus elongatus , similar findings have not been reported from other sites. Soil Microfauna in 0–10 cm soil under a sheep-grazed pasture on a sand was assessed quarterly in FACE rings that were either at ambient CO_2 or had been exposed to 475 μl l^−1 CO_2 for some 9 years. Although the area had been subject to a severe drought and Microfaunal populations were lower than previously found, the effects of elevated CO_2 on Microfaunal populations were broadly similar to those at 4 years. Average populations of the root-feeding L. elongatus increased from 67,000 to 233,000 m^−2 (3.48×) compared with a 4.26× increase after 4 years; microbial-feeding nematodes increased slightly, while predacious nematodes showed a 2.0× increase. A pot experiment showed an additive effect of elevated CO_2 and L. elongatus abundance in reducing specific root length. That similar effects have been found 4 and 9 years after CO_2 enrichment commenced suggests they are real, and emphasises the difference to other sites around the world where much lower responses to elevated CO_2 have been found. This, in part, reflects the unique combination of soil, plant and soil biological conditions at each site and confirms the strong effect of soil type and vegetation on soil biological processes. Just as the effects of global climate change on a given region are idiosyncratic, so it seems are the effects of elevated CO_2 on soil and ecosystem processes. In part, this reflects our limited understanding of below-ground processes.
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significant changes in soil Microfauna in grazed pasture under elevated carbon dioxide
Biology and Fertility of Soils, 2003Co-Authors: G W Yeates, Paul C. D. Newton, D J RossAbstract:Soil Microfauna in 0- to 10-cm soil under grazed pasture on a sand (Mollic Psammaquent) was assessed quarterly in free air CO2 enrichment (FACE) rings that were at either ambient CO2 or had been exposed to 475 μl l−1 CO2 for 4–5 years. There were significant increases in nematode (1.5×) and rotifer (4.1×) abundance in soils subjected to elevated CO2. Ten nematode taxa were significantly more abundant under elevated CO2. The greatest increase was 4.3× in root-feeding Longidorus; three other root-feeders showed no increase in population densities at elevated CO2. Bacterial-feeding Cervidellus was the only nematode with a significant decrease (0.4×). The abundance of all nematode feeding groups increased significantly in soils subjected to elevated CO2. The relative increases in abundance of feeding groups (bacterial-feeders 1.3×, root-feeders 1.3×, plant-associated 1.5×, fungal-feeders 1.6×, omnivores 2.0×, predators 2.1×) suggest marked increases in fluxes through microbial-feeding nematodes and a multitrophic response among the soil biota to the increase in atmospheric CO2 above ambient. Data from the site suggest soil microbial biomass C and N pools were unchanged over the sampling period. Of eight nematode indices only total maturity index increased (2.9 to 3.2), reflecting the increased proportion of the large Longidorus. Further work on microbial-Microfaunal interactions and their micro-scale relation to roots is needed to better understand the impact of increasing atmospheric CO2 on soil processes.
Gregor W. Yeates - One of the best experts on this subject based on the ideXlab platform.
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Long-term changes in topsoil nematode populations in grazed pasture under elevated atmospheric carbon dioxide
Biology and Fertility of Soils, 2009Co-Authors: Gregor W. Yeates, Paul C. D. NewtonAbstract:Increasing atmospheric CO_2 concentrations are expected to affect ecosystems processes, and while a New Zealand study reported a response in soil biological activity after 4 years of CO_2 enrichment, apparently reflecting increased populations of Longidorus elongatus , similar findings have not been reported from other sites. Soil Microfauna in 0–10 cm soil under a sheep-grazed pasture on a sand was assessed quarterly in FACE rings that were either at ambient CO_2 or had been exposed to 475 μl l^−1 CO_2 for some 9 years. Although the area had been subject to a severe drought and Microfaunal populations were lower than previously found, the effects of elevated CO_2 on Microfaunal populations were broadly similar to those at 4 years. Average populations of the root-feeding L. elongatus increased from 67,000 to 233,000 m^−2 (3.48×) compared with a 4.26× increase after 4 years; microbial-feeding nematodes increased slightly, while predacious nematodes showed a 2.0× increase. A pot experiment showed an additive effect of elevated CO_2 and L. elongatus abundance in reducing specific root length. That similar effects have been found 4 and 9 years after CO_2 enrichment commenced suggests they are real, and emphasises the difference to other sites around the world where much lower responses to elevated CO_2 have been found. This, in part, reflects the unique combination of soil, plant and soil biological conditions at each site and confirms the strong effect of soil type and vegetation on soil biological processes. Just as the effects of global climate change on a given region are idiosyncratic, so it seems are the effects of elevated CO_2 on soil and ecosystem processes. In part, this reflects our limited understanding of below-ground processes.
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Long-term changes in topsoil nematode populations in grazed pasture under elevated atmospheric carbon dioxide
Biology and Fertility of Soils, 2009Co-Authors: Gregor W. Yeates, Paul C. D. NewtonAbstract:Increasing atmospheric CO_2 concentrations are expected to affect ecosystems processes, and while a New Zealand study reported a response in soil biological activity after 4 years of CO_2 enrichment, apparently reflecting increased populations of Longidorus elongatus , similar findings have not been reported from other sites. Soil Microfauna in 0–10 cm soil under a sheep-grazed pasture on a sand was assessed quarterly in FACE rings that were either at ambient CO_2 or had been exposed to 475 μl l^−1 CO_2 for some 9 years. Although the area had been subject to a severe drought and Microfaunal populations were lower than previously found, the effects of elevated CO_2 on Microfaunal populations were broadly similar to those at 4 years. Average populations of the root-feeding L. elongatus increased from 67,000 to 233,000 m^−2 (3.48×) compared with a 4.26× increase after 4 years; microbial-feeding nematodes increased slightly, while predacious nematodes showed a 2.0× increase. A pot experiment showed an additive effect of elevated CO_2 and L. elongatus abundance in reducing specific root length. That similar effects have been found 4 and 9 years after CO_2 enrichment commenced suggests they are real, and emphasises the difference to other sites around the world where much lower responses to elevated CO_2 have been found. This, in part, reflects the unique combination of soil, plant and soil biological conditions at each site and confirms the strong effect of soil type and vegetation on soil biological processes. Just as the effects of global climate change on a given region are idiosyncratic, so it seems are the effects of elevated CO_2 on soil and ecosystem processes. In part, this reflects our limited understanding of below-ground processes.
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Changes in the community structure and diversity of soil invertebrates across the Franz Josef Glacier chronosequence
Soil Biology and Biochemistry, 2008Co-Authors: Enrique Doblas-miranda, Duane A. Peltzer, David A. Wardle, Gregor W. YeatesAbstract:Following the creation of new land surfaces, there is an initial build-up phase of ecosystem development, but after a prolonged absence of major disturbance a retrogressive (decline) phase often follows due to reduced nutrient availability over time. Although many studies have considered how the soil community changes during the build-up phase, the response of this community to the retrogressive phase is poorly known. We measured litter and soil communities of Microfauna and macrofauna along the Franz Josef Glacier chronosequence in New Zealand that spans ca. 120,000 years, and includes well-established build-up and retrogressive stages. We aimed to assess whether the abundances, community structure and diversity of these groups show the same pattern across the sequence as that for vegetation. With regard to Microfaunal abundances, litter-dwelling microbe-feeding nematodes were most abundant in the first stage of the chronosequence, but several other groups of Microfauna in both the soil and litter increased sharply during the first few stages and declined sharply during the last (retrogressive) stages. The ratios of bacterial- to fungal-feeding nematodes in both soil and litter were lowest for the final stages of the chronosequence, and (in the case of soil) for some of the early stages, pointing to domination by the fungal-based energy channel at those stages for which soil organic matter content or quality were lowest. This is consistent with the fungal-based energy channel being better adapted than the bacterial-based channel for resource-poor conditions. The main groups of macroinvertebrates typically had their lowest abundances at the very early and late stages of the chronosequence, although the relative abundances of different taxa differed during the intermediate stages. Taxonomic diversity of nematodes and macroinvertebrates in both litter and soil varied strongly with chronosequence stage but differed among taxa; diversity of only one group (macroinvertebrates in litter) declined significantly during retrogression. Diversity of nematodes and macroinvertebrates along the sequence did not closely match tree diversity or soil chemical properties, but community composition of these groups was often related to tree community composition and ratios of soil C to N, C to P and N to P. Different groups of soil invertebrates show contrasting responses to chronosequence stage, probably because they differ in their relative response to bottom-up and top-down controls. However, the abundance of most groups increased during the build-up phase and declined during retrogression. As such, the build-up and decline phases observed for plant communities and ecosystem processes across long-term chronosequences also apply to soil communities, pointing to the importance of resource availability as a major driver of soil biota during long-term ecosystem change.
Yu Zhang - One of the best experts on this subject based on the ideXlab platform.
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dynamics of the Microfauna community in a full scale municipal wastewater treatment plant experiencing sludge bulking
European Journal of Protistology, 2013Co-Authors: Yu Zhang, Xue Bai, Haipeng Bao, Yang Wen, Min YangAbstract:We investigated the dynamics of the Microfauna community in activated sludge, with special reference to sludge bulking, in two parallel municipal wastewater treatment systems in Beijing, China over a period of 14 months. Annual cyclic changes in Microfauna community structures occurred in both systems. RELATE analysis based on Spearman's Rank correlation indicated that Microfauna community structures were highly correlated with the sludge volume index (SVI) (p<0.001), which indicates sludge settleability. Nutrient conditions of raw sewage (p<0.01) and hydraulic retention time (HRT) (p<0.05) were also related to Microfauna community structures. Abundances of the species Epistylis plicatilis and Vorticella striata increased significantly with an increase in SVI (p<0.001) and decrease in water temperature (p<0.001), suggesting that sludge bulking may have created favorable conditions for the two species, even under unfavorable temperature conditions. Sludge de-flocculation primarily due to the excessive growth of Microthrix parvicella-like filaments could be an important driving force for the Microfauna community changes. The release of flocculated non-filamentous bacteria may represent a suitable food source for these species. The two species may be considered as potential bioindicators for sludge bulking.
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dynamics of the Microfauna community in a full scale municipal wastewater treatment plant experiencing sludge bulking
European Journal of Protistology, 2013Co-Authors: Bo Hu, Yu Zhang, Rong Qi, Wei An, Muqi Xu, Jian Gu, Min YangAbstract:We investigated the dynamics of the Microfauna community in activated sludge, with special reference to sludge bulking, in two parallel municipal wastewater treatment systems in Beijing, China over a period of 14 months. Annual cyclic changes in Microfauna community structures occurred in both systems. RELATE analysis based on Spearman's Rank correlation indicated that Microfauna community structures were highly correlated with the sludge volume index (SW) (p<0.001), which indicates sludge settleability. Nutrient conditions of raw sewage (p<0.01) and hydraulic retention time (HRT) (p<0.05) were also related to Microfauna community structures. Abundances of the species Epistylis plicatilis and Vorticella striata increased significantly with an increase in SW (p<0.001) and decrease in water temperature (p<0.001), suggesting that sludge bulking may have created favorable conditions for the two species, even under unfavorable temperature conditions. Sludge de-flocculation primarily due to the excessive growth of Microthrix parvicella-like filaments could be an important driving force for the Microfauna community changes. The release of flocculated non-filamentous bacteria may represent a suitable food source for these species. The two species may be considered as potential bioindicators for sludge bulking. (C) 2013 Elsevier GmbH. All rights reserved.
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Dynamics of the Microfauna community in a full-scale municipal wastewater treatment plant experiencing sludge bulking
European journal of protistology, 2013Co-Authors: Yu Zhang, Xue Bai, Haipeng Bao, Yang Wen, Min YangAbstract:We investigated the dynamics of the Microfauna community in activated sludge, with special reference to sludge bulking, in two parallel municipal wastewater treatment systems in Beijing, China over a period of 14 months. Annual cyclic changes in Microfauna community structures occurred in both systems. RELATE analysis based on Spearman's Rank correlation indicated that Microfauna community structures were highly correlated with the sludge volume index (SVI) (p
Guoji Ding - One of the best experts on this subject based on the ideXlab platform.
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Determination and comparison of sludge reduction rates caused by Microfaunas' predation.
Bioresource technology, 2005Co-Authors: Peng Liang, Xia Huang, Yi Qian, Yuansong Wei, Guoji DingAbstract:Using micorfauna to reduce excess sludge is a potentially effective ecological technology and scaling the rate of sludge reduction rate is the first step. A method to scale the rate of sludge reduction caused by Microfauna was proposed, and comparison of sludge reduction rates induced by four Microfaunas was carried out. The principle of this method is based on the change of carbon forms. The rate of sludge reduction was correlated with the rate at which solids were changed into liquid and gas. Four Microfaunas, including Aeolosoma hemprichi, Daphnia magna, Tubifex tubifex and Physa acuta, were cultured with sterilized sludge in a covered sterilized bottle and were then isolated from the atmosphere above the liquid phase. The rates of sludge reduction using the four Microfaunas were 0.8, 0.18, 0.54 and 0.1 mg-sludge/(mg-Microfauna d), respectively, changing with the Microfaunas' phylum or class and body size. Based on the change of carbon (C) forms, the proposed method produced accurate results similar to those produced using the direct measuring method.