scholarly journals Magnetic sorption materials for recovery of organic anions from aqueous solutions

2021 ◽  
Vol 340 ◽  
pp. 01037
Author(s):  
Yuliya Petrova ◽  
Ekaterina Sevast’yanova ◽  
Yuliya Mateyshina
Keyword(s):  
Thermal Decomposition ◽  
Magnetic Properties ◽  
Glutamic Acid ◽  
Sorption Kinetics ◽  
Precipitation Method ◽  
Decomposition Products ◽  
Maximum Sorption Capacity ◽  
Anionic Clays ◽  
Thermal Decomposition Products ◽  
Static Conditions

Layered double hydroxides (LDHs) belong to the class of two-dimensional anionic clays with a layered structure similar to brucite. The combination of sorption and magnetic properties of layered materials is promising. In this work, magnetic materials based on LDHs (MLDHs) were synthesized and their sorption and magnetic properties were studied. The synthesis of LDHs was carried out by a co-precipitation method followed by calcination. Intercalated Mg, Fe(III)-, Mg, Fe(III), Al-and Mg, Al-LDHs were prepared using LDHs by rehydration in solutions of iron(III) citrate (Cit) or oxalate (Ox) followed by the calcination at 400°C for 2-4 h. LDHs and their thermal decomposition products were characterized by FTIR spectroscopy, laser and X-ray diffraction and thermogravimetry. The sorption experiment was carried out under static conditions using glutamic acid (Glu) as a model organic compound. The maximum sorption capacity of Mg, Fe(III)-LDH and Mg, Al-FeCit-LDH calcined at 400°C was 6.6 and 8.8 mg/g Glu, respectively. The sorption kinetics of intercalated and calcined Mg, Al-and Mg, Fe(III), Al-LDH and calcined at 500º C Mg, Fe(III)-LDH was described by the pseudo-second order model. The magnetic properties of the LDHs and thermal decomposition products were retained after the adsorption of glutamic acid, making it possible to easily separate these MLDHs from the solution by magnetic field.

Theoretical study on the formation of carbon disulfide and ammonia from thermal decomposition products of thiourea

2014 ◽  
Vol 13 (04) ◽  
pp. 1450022 ◽  
Author(s):  
Zerong Daniel Wang ◽  
Meagan Hysmith ◽  
Perla Cristina Quintana
Keyword(s):  
Thermal Decomposition ◽  
Carbon Disulfide ◽  
Density Functional ◽  
Basis Sets ◽  
Structural Isomer ◽  
Consecutive Reaction ◽  
Functional Theory ◽  
Decomposition Products ◽  
Thermal Decomposition Products ◽  
Hybrid Module

The formation of carbon disulfide ( CS 2) and ammonia ( NH 3) from the thermal decomposition products of thiourea has been studied with MP2, and hybrid module-based density functional theory methods (B3LYP, MPW1PW91 and PBE1PBE), each in conjunction with five different basis sets (6-31+G(2d,2p), 6-311++G(2d,2p), DGDZVP, DGDZVP2 and DGTZVP). The free energy changes and activation energies for all the five primitive reactions involved in the formation of CS 2 and NH 3 have been compared and discussed. The results indicate that CS 2 is most likely formed in a consecutive reaction path that consists of the addition of hydrogen sulfide ( H 2 S ) to isothiocyanic acid (HNCS) to generate carbamodithioic acid and subsequent decomposition of carbamodithioic acid. By contrast, thiocyanic acid (HSCN) as the structural isomer of isothiocyanic acid is not likely the source of CS 2.

Transport and condensation of soft a-C:H film thermal decomposition products

2003 ◽  
Vol 313-316 ◽  
pp. 460-464 ◽  
Author(s):  
A.E. Gorodetsky ◽  
R.Kh. Zalavutdinov ◽  
I.I. Arkhipov ◽  
V.Kh. Alimov ◽  
A.P. Zakharov ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Decomposition Products ◽  
Thermal Decomposition Products

scholarly journals STUDY OF THERMAL DECOMPOSITION PRODUCTS OF NITROGEN-PHOSPHORUS-POTASSIUM FERTILIZERS BASED ON AMMONIUM NITRATE BY X-RAY DIFFRACTUON

2017 ◽  
Vol 61 (1) ◽  
pp. 72
Author(s):  
Konstantin G. Gorbovskiy ◽  
Alena S. Ryzhova ◽  
Andrey M. Norov ◽  
Denis A. Pagaleshkin ◽  
Valentina N. Kalinina ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Thermal Decomposition ◽  
Phosphoric Acid ◽  
Ammonium Nitrate ◽  
Confined Space ◽  
Decomposition Products ◽  
X Ray ◽  
Thermal Decomposition Products ◽  
Nitrogen Phosphorus ◽  
Thermal Stability Of

Complex mineral ammonium nitrate-based fertilizers are complex multicomponent salt systems possessing low thermal stability and prone to self-sustaining decomposition. This leads to the need to increase the requirements for fire and explosion safety in their manufacture, storage and transportation, caused by the fact that ammonium nitrate is a solid oxidant able to support a combustion, and its heating in confined space can lead to detonation. Components that make up such fertilizers can both reduce (phosphates and ammonium sulfate) and accelerate (chlorine compounds) decomposition of ammonium nitrate. Thus, the thermal stability of fertilizers based on ammonium nitrate largely depends on the ratio of the components that make up its composition or formed as a result of the chemical reaction. The simplest way to reduce the content of ammonium nitrate and increase the thermal stability of fertilizer without changing the content of essential nutrients is to increase the degree of phosphoric acid ammoniation. In this paper, the phase composition change of grade 22:11:11 nitrogen-phosphorus-potassium fertilizer obtained with different ammoniation degree in the process of thermal decomposition was studied by X-ray phase analysis. To obtain this fertilizer, wet-process phosphoric acid obtained sulfuric acid attack of the Khibin apatite concentrate by a hemihydrate method is used. It is shown that an increase in the ammoniation degree has a significant effect on the exothermic decomposition of ammonium nitrate and the amount of material that is released into the gas phase. The phases formed at each stage of the decomposition are determined.Forcitation:Gorbovskiy K.G., Ryzhova A.S., Norov A.M., Pagaleshkin D.A., Kalinina V.N., Mikhaylichenko A.I. Study of thermal decomposition products of nitrogen-phosphorus-potassium fertilizers based on ammonium nitrate by X-ray diffractuon. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 1. P. 72-77

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