Reduction of Organic Compounds by Lithium in Low Molecular Weight Amines. IV. The Effect of Nitro and Amino Groups on the Course of the Reduction

1958 ◽  
Vol 80 (24) ◽  
pp. 6573-6577 ◽  
Author(s):  
Robert A. Benkeser ◽  
Rogers F. Lambert ◽  
Patrick W. Ryan ◽  
Donald G. Stoffey
Tellus B ◽  
1992 ◽  
Vol 44 (5) ◽  
pp. 533-544 ◽  
Author(s):  
M. C. Facchini ◽  
S. Fuzzi ◽  
J. A. Lind ◽  
H. Fierlinger-Oberlinninger ◽  
M. Kalina ◽  
...  

Membranes ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 58
Author(s):  
Renata Żyłła ◽  
Magdalena Foszpańczyk ◽  
Magdalena Olak-Kucharczyk ◽  
Joanna Marszałek ◽  
Stanisław Ledakowicz

The research covered the process of nanofiltration of low molecular weight organic compounds in aqueous solution. The article presents the results of experiments on membrane filtration of compounds containing amino groups in the aromatic ring and comparing them with the results for compounds without amino groups. The research was carried out for several commercial polymer membranes: HL, TS40, TS80, DL from various manufacturers. It has been shown that the presence of the amino group and its position in relation to the carboxyl group in the molecule affects the retention in the nanofiltration process. The research also included the oxidation products of selected pharmaceuticals. It has been shown that 4-Amino-3,5-dichlorophenol—a oxidation product of diclofenac and 4-ethylbenzaldehyde—a oxidation product of IBU, show poor separation efficiency on the selected commercial membranes, regardless of the pH value and the presence of natural organic matter (NOM). It has been shown that pre-ozonation of natural river water can improve the retention of pollutants removed.


2020 ◽  
Vol 81 (2) ◽  
pp. 301-308 ◽  
Author(s):  
Wenzhe Song ◽  
Yu Zhang ◽  
Amir Hossein Hamidian ◽  
Min Yang

Abstract The biodegradation of polyacrylamide (PAM) includes the hydrolysis of amino groups and cleavage of the carbon chain; however, the effect of molecular weight on the biodegradation needs further investigations. In this study, biodegradation of low molecular weight PAM (1.6 × 106 Da) was evaluated in two aerobic (25 °C and 40 °C) and two anaerobic (35 °C and 55 °C) reactors over 100 days. The removal of the low molecular weight PAM (52.0–52.6%) through the hydrolysis of amino groups by anaerobic treatment (35 °C and 55 °C) was much higher than that of the high molecular weight (2.2 × 107 Da, 11.2–17.0%) observed under the same conditions. The molecular weight was reduced from 1.6 × 106 to 6.45–7.42 × 105 Da for the low molecular weight PAM, while the high molecular weight PAM declined from 2.2 × 107 to 3.76–5.87 × 106 Da. The results showed that the amino hydrolysis of low molecular weight PAM is easier than that of the high molecular weight one, while the cleavage of its carbon chain is still difficult. The molecular weights of PAM in the effluents from the two aerobic reactors (25 °C and 40 °C) were further reduced to 4.31 × 105 and 5.68 × 105 Da by the biofilm treatment, respectively. The results would be useful for the management of wastewater containing PAM.


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