Evaluation of the impact of single-walled carbon nanotubes in an activated sludge wastewater reactor

2008 ◽  
Vol 58 (3) ◽  
pp. 623-628 ◽  
Author(s):  
Y. Yin ◽  
X. Zhang
Keyword(s):  
Carbon Nanotubes ◽  
Activated Sludge ◽  
Single Walled Carbon Nanotubes ◽  
Phase Iii ◽  
Sludge Flocs ◽  
Single Walled Carbon ◽  
Activated Sludge Reactor ◽  
Solids Retention ◽  
Walled Carbon Nanotubes ◽  
The Impact

This paper evaluated the impact of single-walled carbon nanotubes (SWCNTs) on the performance and activated sludge properties in an activated sludge wastewater reactor. The reactor was shock loaded with 270 mg/L of 90% purified SWCNTs after the reactor reached quasi-steady state and the reactor was monitored for 18 days after the shock loading. Various experimental parameters were measured and compared. Overall the addition of SWCNTs did not negatively impact the performance of the activated sludge reactor; on the other hand, SWCNTs improved sludge settleability and sludge dewaterability. The cake solids of the sludge were increased and the activated sludge flocs became less negatively charged. The positive impacts were more significant in Phase II (after running the reactor for one solids retention time, SRT) than that in Phase III (after running for additional 1.5 SRT).

Mitigation of the impact of single-walled carbon nanotubes on a freshwater green algae:Pseudokirchneriella subcapitata

2011 ◽  
Vol 6 (2) ◽  
pp. 161-172 ◽  
Author(s):  
Sejin Youn ◽  
Randy Wang ◽  
Jie Gao ◽  
Anna Hovespyan ◽  
Kirk J. Ziegler ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Single Walled Carbon Nanotubes ◽  
Single Walled Carbon ◽  
Walled Carbon Nanotubes ◽  
The Impact

Activated sludge microbial community responses to single-walled carbon nanotubes: community structure does matter

2015 ◽  
Vol 71 (8) ◽  
pp. 1235-1240 ◽  
Author(s):  
Qiao Ma ◽  
Yuanyuan Qu ◽  
Wenli Shen ◽  
Jingwei Wang ◽  
Zhaojing Zhang ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Microbial Community ◽  
Activated Sludge ◽  
High Throughput Sequencing ◽  
Alpha Diversity ◽  
Single Walled Carbon Nanotubes ◽  
Community Structures ◽  
Single Walled Carbon ◽  
Microbial Responses ◽  
Walled Carbon Nanotubes

The ecological effects of carbon nanotubes (CNTs) have been a worldwide research focus due to their extensive release and accumulation in environment. Activated sludge acting as an important gathering place will inevitably encounter and interact with CNTs, while the microbial responses have been rarely investigated. Herein, the activated sludges from six wastewater treatment plants were acclimated and treated with single-walled carbon nanotubes (SWCNTs) under identical conditions. Illumina high-throughput sequencing was applied to in-depth analyze microbial changes and results showed SWCNTs differently perturbed the alpha diversity of the six groups (one increase, two decrease, three no change). Furthermore, the microbial community structures were shifted, and specific bacterial performance in each group was different. Since the environmental and operational factors were identical in each group, it could be concluded that microbial responses to SWCNTs were highly depended on the original community structures.

scholarly journals Toxic Effect of Single Walled Carbon Nanotubes Combined with Cadmium to the Crustacean Daphnia magna

2015 ◽  
Vol 42 ◽  
pp. 50-61 ◽  
Author(s):  
Messika Revel ◽  
Michel Fournier ◽  
Christian Gagnon ◽  
Pierre Yves Robidoux
Keyword(s):  
Carbon Nanotubes ◽  
Toxic Effect ◽  
Daphnia Magna ◽  
Single Walled Carbon Nanotubes ◽  
Langmuir Equation ◽  
Batch Experiments ◽  
Cd Toxicity ◽  
Single Walled Carbon ◽  
Walled Carbon Nanotubes ◽  
The Impact

The aim of this study was to assess the impact of single-walled carbon nanotubes (SWCNT) on the toxicity of cadmium (Cd) using the crustacean Daphnia magna. LC50 of Cd and SWCNT alone and combined were calculated and compared. Sorption of Cd on SWCNT was also quantified in separate batch experiments. Results showed that the maximum adsorption of Cd onto SWCNT calculated by the Langmuir equation was 24.4 mg kg-1. LC50s for Cd and SWCNT alone were 252.3 µg L-1 and 1400 µg L-1, respectively. In the presence of 500 and 1000 µg L-1 of SWCNT, Cd LC50s were 127.2 and 120.1 µg L-1 respectively. Therefore, Cd toxicity increased when organisms were exposed to both contaminants which indicated that SWCNT induces a synergistic toxic effect on the survival of D. magna. It appears that even if SWCNT had a low adsorption capacity for Cd, toxicity of the metal can be increased. Our study shows the complexity of SWCNT toxicity and how the understanding of their interactions with other contaminants is crucial to determine the consequences of their release into the environment.

scholarly journals Flexible Electrode Formed by Patterned Layers of Single-Walled Carbon Nanotubes for Optoelectronic Applications

2021 ◽  
Vol 2015 (1) ◽  
pp. 012093
Author(s):  
D M Mitin ◽  
A A Vorobyev ◽  
Y S Berdnikov ◽  
S A Raudik ◽  
A M Mozharov ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Cell Size ◽  
Single Walled Carbon Nanotubes ◽  
Moderate Increase ◽  
Flexible Electrode ◽  
Single Walled Carbon ◽  
Random Character ◽  
Series Of Experiments ◽  
Walled Carbon Nanotubes ◽  
The Impact

Abstract The technology of creating patterned flexible electrodes based on single-walled carbon nanotubes and polydimethylsiloxane was demonstrated in this paper. A series of experiments were carried out to study whether the percolation affects the conductivity of patterned SWCNT layers. It was found that in patterns with the linewidth above 1 μm and the cell size above 50 μm the random character of SWCNT networks may be neglected. The impact of bending on the grid conductivity was studied. We observed a very moderate increase of resistance below 5% under the strain up to 4 %, which is comparable with the previous results for continuous SWCNT layers and shows the improvement in comparison with the previous reports on patterned SWCNT layers.

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