Effect of pH on the Microbial Community Structure of SBBR Autotrophic Nitrogen Removal Process

2011 ◽  
Vol 378-379 ◽  
pp. 428-432
Author(s):  
Yu Qin ◽  
Jing Song Guo ◽  
Fang Fang
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Nitrogen Removal ◽  
Microbial Community Structure ◽  
Anaerobic Bacteria ◽  
Biofilm Reactor ◽  
Active Sludge ◽  
Removal Process ◽  
The Relationship ◽  
Autotrophic Nitrogen Removal

PCR-DGGE was applied to analyze the relationship between pH and the microbial community structure of Sequence Batch Biofilm Reactor (SBBR) autotrophic nitrogen removal process. The reactor was possessed of a high nitrogen removal efficiency at pH=8.0 where the similarity of microbial community structure between active sludge and biofilm samples was the lowest about 84.6% and the richness of bacterial community was the most abundant in biofilm compared with other pH conditions. pH=7.0 was good for the microbes in active sludge but unfavorable for anaerobic bacteria. At pH=9.0, the effects were presented with both bacterial activities and microbial community structure and when pH=6.0 the amount of microbial types dramatically dropped

scholarly journals Microbial community structure and the relationship with soil carbon and nitrogen in an original Korean pine forest of Changbai Mountain, China

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Minghui Liu ◽  
Xin Sui ◽  
Yanbo Hu ◽  
Fujuan Feng
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Organic Carbon ◽  
Microbial Community Structure ◽  
Soil Microbes ◽  
Mixed Forest ◽  
Korean Pine ◽  
Soil Microbial ◽  
The Relationship ◽  
Main Factor

Abstract Background The broad-leaved Korean pine mixed forest is an important and typical component of a global temperate forest. Soil microbes are the main driver of biogeochemical cycling in this forest ecosystem and have complex interactions with carbon (C) and nitrogen (N) components in the soil. Results We investigated the vertical soil microbial community structure in a primary Korean pine-broadleaved mixed forest in Changbai Mountain (from 699 to 1177 m) and analyzed the relationship between the microbial community and both C and N components in the soil. The results showed that the total phospholipid fatty acid (PLFA) of soil microbes and Gram-negative bacteria (G-), Gram-positive bacteria (G+), fungi (F), arbuscular mycorrhizal fungi (AMF), and Actinomycetes varied significantly (p < 0.05) at different sites (elevations). The ratio of fungal PLFAs to bacterial PLFAs (F/B) was higher at site H1, and H2. The relationship between microbial community composition and geographic distance did not show a distance-decay pattern. The coefficients of variation for bacteria were maximum among different sites (elevations). Total soil organic carbon (TOC), total nitrogen (TN), soil water content (W), and the ratio of breast-height basal area of coniferous trees to that of broad-leaved tree species (RBA) were the main contributors to the variation observed in each subgroup of microbial PLFAs. The structure equation model showed that TOC had a significant direct effect on bacterial biomass and an indirect effect upon bacterial and fungal biomass via soil readily oxidized organic carbon (ROC). No significant relationship was observed between soil N fraction and the biomass of fungi and bacteria. Conclusion The total PLFAs (tPLFA) and PLFAs of soil microbes, including G-, G+, F, AMF, and Actinomycetes, were significantly affected by elevation. Bacteria were more sensitive to changes in elevation than other microbes. Environmental heterogeneity was the main factor affecting the geographical distribution pattern of microbial community structure. TOC, TN, W and RBA were the main driving factors for the change in soil microbial biomass. C fraction was the main factor affecting the biomass of fungi and bacteria and ROC was one of the main sources of the microbial-derived C pool.

Effects of temperature gradients on AOB/NOB competition in MABR biofilms

2020 ◽  
Author(s):  
Patricia Perez ◽  
Emily Clements ◽  
Cristian Picioreanu ◽  
Robert nerenberg
Keyword(s):  
Wastewater Treatment ◽  
Community Structure ◽  
Microbial Community ◽  
Microbial Community Structure ◽  
Biofilm Reactor ◽  
Temperature Gradients ◽  
Partial Nitrification ◽  
Bulk Liquid ◽  
Ammonia Oxidizing Bacteria ◽  
Activated Sludge Processes

&lt;p&gt;The membrane aerated biofilm reactor (MABR) is an emerging wastewater treatment technology that can greatly decrease energy requirements for wastewater treatment. It consists of cassettes of air-supplying, hollow-fiber membranes that can retrofit existing activated sludge processes. MABR behavior differs from conventional biofilm processes due to the counter-diffusion of the electron donor (ammonia) and acceptor (oxygen).&lt;/p&gt; &lt;p&gt;&amp;#160;&lt;/p&gt; &lt;p&gt;Partial nitrification (PN), or partial nitrification Anammox (PNA), can further improve MABR energy efficiency and cost effectiveness.&amp;#160; To achieve this, ammonia oxidizing bacteria (AOB) must outcompete nitrite-oxidizing bacteria (NOB). &amp;#160;High temperatures favor AOB, but it is not feasible to heat the wastewater influent.&amp;#160; However, high-temperature compressed air can be supplied to the membrane lumen, increasing temperatures inside the biofilm without increasing the bulk temperatures. No previous research has addressed temperature gradients in biofilms, which can lead to gradients in&amp;#160; biodegradation kinetics, diffusivities, and O&lt;sub&gt;2&lt;/sub&gt; solubility.&lt;/p&gt; &lt;p&gt;&amp;#160;&lt;/p&gt; &lt;p&gt;The objective of this research was to explore the effect of temperature gradients in MABR biofilms, especially with respect to PN. We used a one-dimensional multi-species biofilm model, which considers the MABR physical and biochemical behavior, especially with respect to temperature. The model was implemented using COMSOL Multiphysics. We also used bench-scale experiments to explore the effect of biofilm temperature gradients on MABR nitrification and PN performances and microbial community structure.&lt;/p&gt; &lt;p&gt;&amp;#160;&lt;/p&gt; &lt;p&gt;Model simulations showed that MABR biofilms exposed to a temperature gradient from 20 &amp;#186;C (biofilm interior) to 10 &amp;#186;C (bulk liquid) had a 60% increase in nitrification rates compared with biofilms at 10 &amp;#186;C. More importantly, the model predicted a complete out competition of NOBs within the biofilm.&lt;/p&gt; &lt;p&gt;&amp;#160;&lt;/p&gt; &lt;p&gt;Preliminary experimental results confirm a significant (105%) increase in nitrification fluxes with a temperature of 30&amp;#186;C compared to ambient temperatures (20&amp;#186;C). Future experiments will validate the model predicted effects of biofilm temperature gradients on nitrification fluxes and microbial community structure.&lt;/p&gt;

Total electron acceptor loading and composition affect hexavalent uranium reduction and microbial community structure in a membrane biofilm reactor

2017 ◽  
Vol 125 ◽  
pp. 341-349 ◽  
Author(s):  
Aura Ontiveros-Valencia ◽  
Chen Zhou ◽  
Zehra Esra Ilhan ◽  
Louis Cornette de Saint Cyr ◽  
Rosa Krajmalnik-Brown ◽  
...  
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Electron Acceptor ◽  
Microbial Community Structure ◽  
Biofilm Reactor ◽  
Uranium Reduction ◽  
Total Electron ◽  
Hexavalent Uranium ◽  
Membrane Biofilm Reactor
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