Characterization of the biofilm grown on 304L stainless steel in urban wastewaters: extracellular polymeric substances (EPS) and bacterial consortia

Biofouling ◽  
2020 ◽  
Vol 36 (8) ◽  
pp. 977-989
Author(s):  
Islem Ziadi ◽  
Leila El-Bassi ◽  
Latifa Bousselmi ◽  
Hanene Akrout
Metals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 135
Author(s):  
Kathleen Jaffré ◽  
Benoît Ter-Ovanessian ◽  
Hiroshi Abe ◽  
Nicolas Mary ◽  
Bernard Normand ◽  
...  

The effect of dry grinding on 304L stainless steel’s passive behavior is compared to two other surface finishing (mechanical polishing down to 2400 with SiC emery paper and 1 µm with diamond paste, respectively). The characterization of the surface state was performed using scanning electron microscopy, transmission electron microscopy, 3D optical profilometer, and X-ray diffraction. Results indicate that each surface treatment leads to different surface states. The ground specimens present an ultrafine grain layer and a strong plastic deformation underneath the surface, while an ultrafine grain layer characterizes the subsurface of the polished specimens. Grinding induces high residual compressive stresses and high roughness compared to polishing. The characterization of the passive films was performed by electrochemical impedance spectroscopy and Mott–Schottky analysis. The study shows that the semiconductor properties and the thickness of the passive films are dependent on the surface state of the 304L stainless steel.


2020 ◽  
Vol 31 ◽  
pp. 100904 ◽  
Author(s):  
Austin T. Sutton ◽  
Caitlin S. Kriewall ◽  
Ming C. Leu ◽  
Joseph W. Newkirk ◽  
Ben Brown

2016 ◽  
Vol 24 (05) ◽  
pp. 1750064
Author(s):  
R. KUMAR ◽  
M. BALASUBRAMANIAN

The main purpose of the current research work is to identify and investigate a novel method of holding an intermediate metal and to evaluate its metallurgical and mechanical properties. Copper was used as an interlayer material for the welding of this dissimilar Ti–6Al–4V (Ti alloy) and 304L stainless steel (SS). The study shows that the input parameters and surface geometry played a very significant role in producing a good quality joints with minimum heat affected zone and metal loss. A sound weld was achieved between Ti–6Al–4V and SS304L, on the basis of the earlier experiments conducted by the authors in their laboratory, by using copper rod as intermediate metal. Box–Behnken method was used for performing a minimum number of experiments for the study. In the present study, Ti–6Al–4V alloy and SS304L were joined by a novel method of holding the interlayer and new surface geometry for the interlayer. Initially, the drop test was used for determining the quality of the fabricated joint and, subsequently, non-destructive techniques like radiography and C-scan were used. Further optical micrograph, SEM–EDS, hardness and tensile test were done for understanding the performance of the joint.


2020 ◽  
Vol 32 ◽  
pp. 100981 ◽  
Author(s):  
Austin T. Sutton ◽  
Caitlin S. Kriewall ◽  
Sreekar Karnati ◽  
Ming C. Leu ◽  
Joseph W. Newkirk

2007 ◽  
Vol 154 (12) ◽  
pp. G291 ◽  
Author(s):  
L. Hamadou ◽  
A. Kadri ◽  
N. Benbrahim ◽  
J-P. Petit

2015 ◽  
Vol 72 (6) ◽  
pp. 990-997 ◽  
Author(s):  
Rocio Ramirez-Vargas ◽  
Nancy Serrano-Silva ◽  
Yendi E. Navarro-Noya ◽  
Rocio J. Alcántara-Hernández ◽  
Marco Luna-Guido ◽  
...  

This present study aimed to characterize the bacterial community in a well-established nitrifying reactor by high-throughput sequencing of 16S rRNA amplicons. The laboratory-scale continuous stirred tank reactor has been supplied with ammonium (NH4+) as sole energy source for over 5 years, while no organic carbon has been added, assembling thus a unique planktonic community with a mean NH4+ removal rate of 86 ± 1.4 mg NH4+-N/(L d). Results showed a nitrifying community composed of bacteria belonging to Nitrosomonas (relative abundance 11.0%) as the sole ammonia oxidizers (AOB) and Nitrobacter (9.3%) as the sole nitrite oxidizers (NOB). The Alphaproteobacteria (42.3% including Nitrobacter) were the most abundant class within the Proteobacteria (62.8%) followed by the Gammaproteobacteria (9.4%). However, the Betaproteobacteria (excluding AOB) contributed only 0.08%, confirming that Alpha- and Gammaproteobacteria thrived in low-organic-load environments while heterotrophic Betaproteobacteria are not well adapted to these conditions. Bacteroidetes, known to metabolize extracellular polymeric substances produced by nitrifying bacteria and secondary metabolites of the decayed biomass, was the second most abundant phylum (30.8%). It was found that Nitrosomonas and Nitrobacter sustained a broad population of heterotrophs in the reactor dominated by Alpha- and Gammaproteobacteria and Bacteroidetes, in a 1:4 ratio of total nitrifiers to all heterotrophs.


1987 ◽  
Vol 10 (2-3) ◽  
pp. 163-167 ◽  
Author(s):  
F. Gaillard ◽  
M. Romand ◽  
H. Hocquaux ◽  
J. S. Solomon

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