scholarly journals Effect of the Oxidative Phosphorylation Uncoupler Para-Nitrophenol on the Activated Sludge Community Structure and Performance of a Submerged Membrane Bioreactor

Water ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 3222
Author(s):  
Ioannis Stavrakakis ◽  
Nikolaos Remmas ◽  
Paraschos Melidis ◽  
Spyridon Ntougias
Keyword(s):  
Community Structure ◽  
Activated Sludge ◽  
Removal Efficiency ◽  
Extracellular Polymeric Substances ◽  
Nitrifying Bacteria ◽  
Submerged Membrane Bioreactor ◽  
N Removal ◽  
Microbial Products ◽  
And Performance ◽  
Hydrolysis Of

In this work, the metabolic uncoupler para-nitrophenol (pNP) was applied to suppress excess sludge production and to investigate its effects on the system’s performance and activated sludge community structure. The COD removal efficiency decreased from 99.0% to 89.5% prior to and after pNP addition, respectively. Application of pNP transiently reduced NH4+-N, NO3−-N and NO2−-N removal efficiencies, suggesting partial inhibition of both nitrifying and denitrifying activity. However, no changes in the relative abundance of the nitrifying bacteria occurred. Phosphorus removal efficiency was sharply reduced after pNP addition, as the consequence of hydrolysis of stored cell reserves. Tetrasphaera, a key polyphosphate accumulating organism, was also affected by the addition of pNP, a fact that highly influenced system’s ability to remove phosphorus. A drastic drop in Soluble Microbial Products (SMP) and Extracellular Polymeric Substances (EPS) was also detected shortly after the introduction of the uncoupler. On the other hand, MBR’s physicochemical parameters were restored to initial values a week after the addition of pNP. Moreover, remarkable changes in beta-diversity were noted after pNP addition. An increase of Bacteroidetes, Gammaproteobacteria and Firmicutes over Actinobacteria and Alphaproteobacteria was also observed after pNP addition.

Effect of continuously dosing Cu(II) on pollutant removal and soluble microbial products in a sequencing batch reactor

2015 ◽  
Vol 72 (9) ◽  
pp. 1653-1661 ◽  
Author(s):  
YangWei Yan ◽  
YuWen Wang ◽  
Yan Liu ◽  
Xiang Liu ◽  
ChenChao Yao ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Extracellular Polymeric Substances ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Pollutant Removal ◽  
Cod Removal ◽  
Synthetic Wastewater ◽  
Soluble Microbial Products ◽  
Cod Removal Efficiency ◽  
Microbial Products

The effects of synthetic wastewater that contained 20 mg/L Cu(II) on the removal of organic pollutants in a sequencing batch reactor were investigated. Results of continuous 20 mg/L Cu(II) exposure for 120 days demonstrated that the chemical oxygen demand (COD) removal efficiency decreased to 42% initially, followed by a subsequent gradual recovery, which peaked at 78% by day 97. Effluent volatile fatty acid (VFA) concentration contributed 67 to 89% of the influent COD in the experimental reactor, which indicated that the degradation of the organic substances ceased at the VFA production step. Meanwhile, the varieties of soluble microbial products (SMP) content and main components (protein, polysaccharide, and DNA) were discussed to reveal the response of activated sludge to the toxicity of 20 mg/L Cu(II). The determination of Cu(II) concentrations in extracellular polymeric substances (EPS) and SMP throughout the experiment indicated an inverse relationship between extracellular Cu(II) concentration and COD removal efficiency.

Simultaneous biological removal of sulphide and nitrate by autotrophic denitrification in an activated sludge system

2006 ◽  
Vol 53 (12) ◽  
pp. 91-99 ◽  
Author(s):  
I. Manconi ◽  
A. Carucci ◽  
P. Lens ◽  
S. Rossetti
Keyword(s):  
Activated Sludge ◽  
Removal Efficiency ◽  
Electron Donor ◽  
Product Formation ◽  
Fish Analysis ◽  
Autotrophic Denitrification ◽  
Biological Removal ◽  
N Removal ◽  
Activated Sludge Reactor ◽  
Denitrification Process

The feasibility of an autotrophic denitrification process in an activated sludge reactor, using sulphide as the electron donor, was tested for simultaneous denitrification and sulphide removal. The reactor was operated at nitrate (N) to sulphide (S) ratios between 0.5 and 0.9 to evaluate their effect on theN-removal efficiency, the S-removal efficiency and the product formation during anoxic oxidation of sulphide. One hundred per cent removal of both nitrate and sulphide was achieved at a NLR of 7.96 mmol N·L−1·d−1 (111.44 mg NO3−-N·L−1·d−1) and at a N/S ratio of 0.89 with complete oxidation of sulphide to sulphate. The oxygen level in the reactor (10%) was found to influence the N-removal efficiency by inhibiting the denitrification process. Moreover, chemical (or biological) oxidation of sulphide with oxygen occurred, resulting in a loss of the electron donor. FISH analysis was carried out to study the microbial population in the system.

scholarly journals Study on the diversity of denitrification bacteria treating with wastewater by using PPGC filler on SBMBBR at low temperature

2020 ◽  
Vol 158 ◽  
pp. 04002
Author(s):  
Jinxiang Fu ◽  
Zhe Zhang ◽  
Jinghai Zhu
Keyword(s):  
Waste Water ◽  
Low Temperature ◽  
Activated Sludge ◽  
Removal Efficiency ◽  
Relative Abundance ◽  
High Throughput Sequencing ◽  
Denitrifying Bacteria ◽  
Nitrifying Bacteria ◽  
Ammonia Oxidizing Bacteria ◽  
Biological Nitrogen

Aiming at the problem of the low removal efficiency of biological nitrogen-removing of low temperature waste-water, using Polyurethane Porous Gel Carrier (PPGC)-SBMBBR treated low temperature sewage, in compared with conventional SBR,and viaing Miseq high-throughput sequencing technology in analysis of the differences of microbial diversity and abundance of structure on the two reactors of activated sludge, revealed dominant nitrogen-removing bacterium improving the treatment efficiency of low temperature sewage. The results shows that the removal efficiency of the effluent nitrogen and the sludge sedimentation rate of (PPGC)-SBMBBR reactor are significantly improved under the water temperature (6.5±1℃). Adding the filler can contribute to improvement of bacterial diversity and relative abundance of nitrification and denitrification bacterium in the activated sludge system. The main relative abundance of ammonia oxidizing bacteria (AOB),nitrite oxidizing bacteria (NOB),anaerobic denitrifying bacteria, and aerobic denitrifying bacteria in (PPGC)-SBMBBR(R2) are significantly better than SBR (R1),and the R2 reactor can independently enrich the nitrifying bacteria and the aerobic denitrifying bacteria, such as Nitrospira, Hydrogens, Pseudomonas, and Zoogloea. The total relative abundance of dominant and nitrifying denitrifying bacterium increases from 28.65% of R1 to 60.23% of R2, providing a microbiological reference for improving the efficiency of biological nitrogen removal in low temperature waste-water.

Effects of Ce3+ Addition on Granulation of Activated Sludge

2014 ◽  
Vol 1004-1005 ◽  
pp. 990-995
Author(s):  
Yu Xiao Zhao ◽  
Min Tian Gao ◽  
Xiao Hui Liang ◽  
Hui Mu
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Activated Sludge ◽  
Protein Content ◽  
Removal Efficiency ◽  
Extracellular Polymeric Substances ◽  
Cod Removal ◽  
Aerobic Granules ◽  
Sludge Granulation ◽  
Scanning Electron

In this study the effect of Ce3+ on activated sludge granulation were first studied. It was found that 50 mg/l Ce3+ significantly promotes the granulation of activated sludge and more compacted smaller aerobic granules are formed. Additional Ce3+ has no influences on COD removal efficiency, but improved the SOP removal efficiency significantly. Although protein contents in extracellular polymeric substances increased along with granulation in both reactors, protein content in EPS of Ce3+-fed granules was higher than that without Ce3+ addition. Polysaccharide contents in extracellular polymeric substances decreased slightly through the experiment in the two reactors. Scanning electron microscopy showed that bacilli and cocci were dominant on surface of granules in both reactors. But there were more and longer rod-shaped bacteria on surface of Ce3+-fed granules.

Modeling of extracellular polymeric substances and soluble microbial products production in a submerged membrane bioreactor at various SRTs

2006 ◽  
Vol 53 (7) ◽  
pp. 209-216 ◽  
Author(s):  
Y.T. Ahn ◽  
Y.K. Choi ◽  
H.S. Jeong ◽  
S.R. Chae ◽  
H.S. Shin
Keyword(s):  
Activated Sludge ◽  
Membrane Bioreactor ◽  
Extracellular Polymeric Substances ◽  
Model Simulation ◽  
Kinetic Constant ◽  
Soluble Microbial Products ◽  
Membrane Biofouling ◽  
Microbial Products ◽  
Predicted Values ◽  
Set Up

Extracelluar polymeric substances (EPSs) and soluble microbial products (SMPs) produced by microbial cultures involved in membrane biofouling have been widely investigated. A mathematical model of EPS and SMP formation and degradation was established based on the activated sludge model no. 1 (ASM1) and was applied to the membrane bioreactor sludge with different sludge retention times (SRTs). The unified theory that the distinct products from the EPS and SMP overlapped each other was integrated into the ASM1. Two components, five processes and eight parameters were newly added to set up the model. To increase the accuracy of model simulation, microbial kinetic parameters were determined by respirometry method and applied to the model instead of microbial kinetic constant offered in ASM1. From the respirometry result, both of heterotroph and autotroph showed different yield value, growth rate and decay rate from activated sludge. There was no significant effect of SRT on SMP production and the experimental results showed good agreement with the predicted values by the model simulation. With the developed unified EPS and SMP model, EPS and SMP production could be simulated so well that it can be applied for the membrane biofouling control.

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