Nitrite enhanced copper-based Fenton reactions for biofilm removal

2021 ◽  
Author(s):  
Li Wang ◽  
Rui Peng ◽  
Xue Liu ◽  
Chendi Heng ◽  
Yanni Miao ◽  
...  

Unwanted biofilms present challenges for many industries. Herein an innovative biofilm removal technology was developed based on nitrite-accelerated Fenton chemistry, where both dissolved Cu ions and nano-CuO surfaces efficiently generate...

2017 ◽  
Vol 53 (43) ◽  
pp. 5862-5865 ◽  
Author(s):  
Li Wang ◽  
Yanni Miao ◽  
Mingsheng Lu ◽  
Zhi Shan ◽  
Shan Lu ◽  
...  

Chloride ions dramatically enhance the antibacterial and anti-biofilm capability of Cu-based Fenton reagents.


Biofouling ◽  
2003 ◽  
Vol 19 (3) ◽  
pp. 159-168 ◽  
Author(s):  
Nadia Oulahal- Lagsir ◽  
Adele Martial- Gros ◽  
Marc Bonneauc ◽  
Loic Bluma

Biofouling ◽  
2003 ◽  
Vol 19 (3) ◽  
pp. 159-168 ◽  
Author(s):  
NADIA OULAHAL-LAGSIR ◽  
ADELE MARTIAL-GROS ◽  
MARC BONNEAU ◽  
LOIC BLUM

2013 ◽  
Author(s):  
Farshad Madani ◽  
Benjamin Stolt ◽  
Greg Wease ◽  
Phaneendra Rampalli

1990 ◽  
Vol 22 (7-8) ◽  
pp. 53-60 ◽  
Author(s):  
B. Rabinowitz ◽  
T. D. Vassos ◽  
R. N. Dawson ◽  
W. K. Oldham

A brief review of recent developments in biological nitrogen and phosphorus removal technology is presented. Guidelines are outlined of how current understanding of these two removal mechanisms can be applied in the upgrading of existing wastewater treatment plants for biological nutrient removal. A case history dealing with the upgrading of the conventional activated sludge process located at Penticton, British Columbia, to a biological nutrient removal facility with a design flow of 18,200 m3/day (4.0 IMGD) is presented as a design example. Process components requiring major modification were the headworks, bioreactors and sludge handling facilities.


Author(s):  
Ji-Hyun Lee ◽  
Jin-Hee Ha

This study evaluated the effectiveness of a microcurrent toothbrush (approved by the US Food and Drug Administration [FDA]), which employs a superimposed alternating and direct electric current, named as a Proxywave® technology, similar to the intensity of the biocurrent, in plaque removal and reducing gingivitis by biofilm removal through the bioelectric effect. This study enrolled 40 volunteers with gingivitis. Dental observations were made every two weeks, before and after the use of each toothbrush. We randomly assigned participants into two groups: one group used the Proxywave® toothbrush (PB) for two weeks followed by the control toothbrush (CB) for two weeks, while the other group used the CB for two weeks followed by the PB. The participants had a two-week washout period. If the toothbrush used earlier has had an effect on the bacterial flora in the oral cavity, this is to remove this effect and return it to its previous state. During each dental visit, we recorded plaque index (PI) and gingival index (GI) scores. The PI and GI scores were significantly lower in both the PB and the CB (p < 0.05). Considering the PI, there was no significant difference between the toothbrushes on all the surfaces. Considering the GI, the PB showed a significant decrease in the interproximal surface, compared to the CB (p < 0.05). The PB showed a significant decrease in the interproximal GI and had a beneficial effect in the interproximal area where the bristles could not reach. No adverse events were observed in the participants during the clinical trial. The microcurrent toothbrush is a device that can be safely used for plaque removal.


Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2361
Author(s):  
Yinjiao Su ◽  
Xuan Liu ◽  
Yang Teng ◽  
Kai Zhang

Coal combustion is an anthropogenic source of mercury (Hg) emissions to the atmosphere. The strong toxicity and bioaccumulation potential have prompted attention to the control of mercury emissions. Pyrolysis has been regarded as an efficient Hg removal technology before coal combustion and other utilization processes. In this work, the Hg speciation in coal and its thermal stability were investigated by combined sequential chemical extraction and temperature programmed decomposition methods; the effect of coal rank on Hg speciation distribution and Hg release characteristics were clarified based on the weight loss of coal; the amount of Hg released; and the emission of sulfur-containing gases during coal pyrolysis. Five species of mercury were determined in this study: exchangeable Hg (F1), carbonate + sulfate + oxide bound Hg (F2), silicate + aluminosilicate bound Hg (F3), sulfide bound Hg (F4), and residual Hg (F5), which are quite distinct in different rank coals. Generally, Hg enriched in carbonates, sulfates, and oxides might migrate to sulfides with the transformation of minerals during the coalification process. The order of thermal stability of different Hg speciation in coal is F1 < F5 < F2 < F4 < F3. Meanwhile, the release of Hg is accompanied with sulfur gases during coal pyrolysis, which is heavily dependent on the coal rank.


Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4686
Author(s):  
Jerzy Podobiński ◽  
Mariusz Gackowski ◽  
Grzegorz Mordarski ◽  
Katarzyna Samson ◽  
Michał Śliwa ◽  
...  

The properties of both Cu2+ and Cu+ ions in zeolite CuY were followed with NO and CO as probe molecules. Cu2+ was found to be located in SII, SII*, and SIII sites, whereas Cu+ was found in SII and SII* sites. The fine analysis of the spectra of Cu2+-NO and Cu+-CO adducts suggests that both in SII and in SII* sites two kinds of Cu cations exist. They differ in the positive charge, which may be related to the varying numbers of AlO4− in close proximity. The experiments of NO and CO adsorption and desorption evidenced that both Cu2+ and Cu+ sites of highest positive charge bind probe molecules most strongly but activate them to a lesser extent than the Cu sites of lowest positive charge. The experiments of reduction with hydrogen evidenced that the Cu ions of higher positive charge are first reduced by hydrogen. On the other hand, Cu sites of the lowest positive charge are first oxidized by oxygen. The experiments with CuNaY zeolites of various Cu contents suggest that the first introduced Cu (at low Cu contents) created Cu+, which was the most neutralized by framework oxygens. Such Cu cations are the most stabilized by framework oxygens.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Toshinori Tanaka ◽  
Yoshio Yahata ◽  
Keisuke Handa ◽  
Suresh V. Venkataiah ◽  
Mary M. Njuguna ◽  
...  

Abstract Background We established an in vivo intraradicular biofilm model of apical periodontitis in pigs in which we compared the efficacy of different irrigant activation techniques for biofilm removal. Methods Twenty roots from the deciduous mandibular second premolar of 5 male pigs were used. After pulpectomy, canals were left open for 2 weeks and then sealed for 4 weeks to enable the development of an intracanal biofilm. The intraradicular biofilms was evaluated using SEM and bacterial 16S rRNA gene-sequencing. To investigate the efficacy of biofilm removal, root canal irrigations were performed using conventional needle, passive ultrasonic, subsonic, or laser-activated irrigation. Real-time PCR was conducted to quantitate the remaining biofilm components. Statistical analysis was performed using ANOVA followed by a Tukey kramer post-hoc test with α = 0.05. Results The pulp exposure model was effective in inducing apical periodontitis and SEM analysis revealed a multi-layer biofilm formation inside the root canal. 16S rRNA sequence analysis identified Firmicutes, Bacteroidetes, and Fusobacteria as the predominant bacterial phyla components, which is similar to the microbiome profile seen in humans. None of the tested irrigation techniques completely eradicated the biofilm components from the root canal, but the subsonic and laser-activated irrigation methods produced the lowest bacterial counts (p < 0.05). Conclusions An experimental intraradicular biofilm model has been successfully established in pigs. Within the limitations of the study, subsonic or laser-activated irrigation demonstrated the best biofilm removal results in the pig system.


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