Investigation of the Exfoliation of the Hydrolysis Products of Graphite Bisulfate and Nitrate

1992 ◽  
Vol 91-93 ◽  
pp. 213-218 ◽  
Author(s):  
G.I. Titelman ◽  
V.N. Gelman ◽  
Yu.V. Isaev ◽  
Yu.N. Novkiov
2010 ◽  
Vol 6 (3) ◽  
pp. 174-183 ◽  
Author(s):  
Maria Saavedra ◽  
Anabela Borges ◽  
Carla Dias ◽  
Alfredo Aires ◽  
Richard Bennett ◽  
...  

2021 ◽  
Vol 33 (1) ◽  
Author(s):  
Natasa Skrbic ◽  
Vaidotas Kisielius ◽  
Ann-Katrin Pedersen ◽  
Sarah C. B. Christensen ◽  
Mathilde J. Hedegaard ◽  
...  

Abstract Background Ptaquiloside (PTA), caudatoside (CAU) and ptesculentoside (PTE) are carcinogenic illudane glycosides found in bracken ferns (Pteridium spp.) world-wide. The environmentally mobile PTA entails both acute and chronic toxicity. A comparable risk might be associated with the structurally similar CAU and PTE. It is of great health concern if these compounds are present in drinking water, however, it is currently unknown if these compounds can detected in wells in bracken-dominated regions. This study investigates the presence of PTA, CAU, PTE, and their corresponding hydrolysis products pterosins B (PtB), A (PtA) and G (PtG) in water wells in Denmark, Sweden and Spain. Water samples from a total of 77 deep groundwater wells (40–100 m) and shallow water wells (8–40 m) were collected and preserved in the field, pre-concentrated in the laboratory and analysed by liquid chromatography–mass spectrometry (LC–MS). Results Deep groundwater wells contained neither illudane glycosides nor their pterosins. However, seven private shallow wells contained at least one of the illudane glycosides and/or pterosins at concentrations up to 0.27 µg L−1 (PTA), 0.75 µg L−1 (CAU), 0.05 µg L−1 (PtB), 0.03 µg L−1 (PtA) and 0.28 µg L−1 (PtG). This is the first finding of illudane glycosides and pterosins in drinking water wells. Conclusions Detected concentrations of illudane glycosides in some of investigated wells exceeded the suggested maximum tolerable concentrations of PTA, although they were used for drinking water purpose. Contaminated wells were shallow with neutral pH and lower electric conductivity compared to deep groundwater wells with no illudane glycosides nor pterosins.


1952 ◽  
Vol 199 (2) ◽  
pp. 511-516 ◽  
Author(s):  
M.L. Eidinoff ◽  
H.C. Reilly ◽  
J.E. Knoll ◽  
D.H. Marrian

Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 668
Author(s):  
Justine Oma Angadam ◽  
Seteno Karabo Obed Ntwampe ◽  
Boredi Silas Chidi ◽  
Jun Wei Lim ◽  
Vincent Ifeanyi Okudoh

Human endeavors generate a significant quantity of bio-waste, even lignocellulosic waste, due to rapid industrialization and urbanization, and can cause pollution to aquatic ecosystems, and contribute to detrimental animal and human health because of the toxicity of consequent hydrolysis products. This paper contributes to a new understanding of the lignocellulosic waste bio-pretreatment process from a literature review, which can provide better biorefinery operational outcomes. The simultaneous partial biological lignin, cellulose and hemicellulose lysis, i.e., simultaneous semi-lignino-holocellulolysis, is aimed at suggesting that when ligninolysis ensues, holocellulolysis is simultaneously performed for milled lignocellulosic waste instead of having a sequential process of initial ligninolysis and subsequent holocellulolysis as is currently the norm. It is presumed that such a process can be solely performed by digestive enzyme cocktails from the monkey cups of species such as Nepenthes, white and brown rot fungi, and some plant exudates. From the literature review, it was evident that the pretreatment of milled lignocellulosic waste is largely incomplete, and ligninolysis including holocellulolysis ensues simultaneously when the waste is milled. It is further proposed that lignocellulosic waste pretreatment can be facilitated using an environmentally friendly approach solely using biological means. For such a process to be understood and applied on an industrial scale, an interdisciplinary approach using process engineering and microbiology techniques is required.


1977 ◽  
Vol 15 (3) ◽  
pp. 187-193 ◽  
Author(s):  
P.W. Rankin ◽  
J.G. Surak ◽  
N.P. Thompson

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