Toxicity of a Mixture of Metal Oxide Nanoparticles on Activated Sludge

Author(s):  
Baranidharan Sundaram ◽  
Arun Kumar
2016 ◽  
Vol 75 (2) ◽  
pp. 462-473 ◽  
Author(s):  
Baranidharan Sundaram ◽  
Arun Kumar

This study evaluated the influence of metal oxide nanoparticles (NPs) (Ag2O, TiO2) and their mixture on activated sludge for 180 days. When tested, a mixture of NPs at 1 and 10 mg/L had greater impact than individual NPs, in which maximum reduction in chemical oxygen demand (COD) elimination (76.3%) was observed after 150 days for 1 mg/L (500 mg/L COD concentration) and after 180 days (70.2%) for 10 mg/L (250 mg/L COD concentration). TiO2 had higher inhibition on COD reduction than Ag2O NPs at 1 and 10 mg/L. An antagonistic effect was observed in which the combination of individual NPs had a greater effect than a mixture of NPs. Reduction in COD elimination was found to be dependent on NP type and concentration (p < 0.05). Further, metal ion concentration was higher in sludge than supernatant irrespective of NPs, while microscopic analysis showed the presence of NPs inside activated sludge. Among NPs tested, the concentration of Ti4+ ion was greater in sludge than in the Ag+ ion, thus indicating that TiO2 has a greater affinity than Ag2O NPs. All three factors (NP type, NP concentration, organic concentration) play a significant role in imparting COD removal (p < 0.05). Future studies are required to quantify NP concentration to minimize NP effect on plant performance.


Author(s):  
Sagadevan Suresh ◽  
Selvaraj Vennila ◽  
J. Anita Lett ◽  
Is Fatimah ◽  
Faruq Mohammad ◽  
...  

2021 ◽  
Vol 23 (8) ◽  
Author(s):  
Eliecer Peláez Sifonte ◽  
Fidel Antonio Castro-Smirnov ◽  
Argenis Adrian Soutelo Jimenez ◽  
Héctor Raúl González Diez ◽  
Fernando Guzmán Martínez

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
N. C. Angastiniotis ◽  
S. Christopoulos ◽  
K. C. Petallidou ◽  
A. M. Efstathiou ◽  
A. Othonos ◽  
...  

AbstractA bulk scale process is implemented for the production of nanostructured film composites comprising unary or multi-component metal oxide nanoparticles dispersed in a suitable polymer matrix. The as-received nanoparticles, namely Al$$_2$$ 2 O$$_3$$ 3 , SiO$$_2$$ 2 and TiO$$_2$$ 2 and binary combinations, are treated following specific chemical and mechanical processes in order to be suspended at the optimal size and composition. Subsequently, a polymer extrusion technique is employed for the fabrication of each film, while the molten polymer is mixed with the treated metal oxide nanoparticles. Transmission and reflection measurements are performed in order to map the optical properties of the fabricated, nanostructured films in the UV, VIS and IR. The results substantiate the capability of the overall methodology to regulate the optical properties of the films depending on the type of nanoparticle formation which can be adjusted both in size and composition.


2021 ◽  
Vol 394 (10) ◽  
pp. 1991-2002
Author(s):  
Junchao Luo ◽  
Yin Zhang ◽  
Senbo Zhu ◽  
Yu Tong ◽  
Lichen Ji ◽  
...  

AbstractThe current understanding of osteoarthritis is developing from a mechanical disease caused by cartilage wear to a complex biological response involving inflammation, oxidative stress and other aspects. Nanoparticles are widely used in drug delivery due to its good stability in vivo and cell uptake efficiency. In addition to the above advantages, metal/metal oxide NPs, such as cerium oxide and manganese dioxide, can also simulate the activity of antioxidant enzymes and catalyze the degradation of superoxide anions and hydrogen peroxide. Degrading of metal/metal oxide nanoparticles releases metal ions, which may slow down the progression of osteoarthritis by inhibiting inflammation, promoting cartilage repair and inhibiting cartilage ossification. In present review, we focused on recent research works concerning osteoarthritis treating with metal/metal oxide nanoparticles, and introduced some potential nanoparticles that may have therapeutic effects.


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