scholarly journals SYNTHESIS AND RESEARCH OF CHELATE FORMING SORBENT BASED ON CARBAMIDE, FORMALDEHYDE, DITIZONE

2021 ◽  
pp. 19-23
Keyword(s):  
Reaction Time ◽  
Noble Metals ◽  
Exchange Capacity ◽  
Static Exchange Capacity ◽  
Optimal Conditions ◽  
Optimum Temperature ◽  
Molar Ratios ◽  
Chelating Sorbent ◽  
Sulfur Containing ◽  
Hcl Solution

The purpose of this study is the synthesis and study of a chelating sorbent for the extraction of ions of non-ferrous and noble metals. To achieve this goal, a sulfur-containing chelating sorbent based on carbamide, formaldehyde, and dithizone was synthesized and studied. The optimal conditions for the synthesis of the sorbent have been determined and studies have been carried out on the influence of the molar ratios of the starting materials on the composition, and physicochemical properties of the synthesized sorbent. The optimum temperature of polycondensation was taken as 90 °C, the reaction time is 2.5-3 hours, as a result, the reaction is more uniform and the exchange capacity for a 0.1 N HCl solution reaches 3.8 mg-eq/g. As a result of the studies carried out, the sorbent with the best performance was obtained at a 1: 2: 0.5 ratio of carbamide, formaldehyde, and dithizone, respectively. Based on the results of IR spectroscopy, the reaction of sorbent formation is proposed. The static exchange capacity of the synthesized sorbent for metal ions was determined, mg-eq/g: Cu (II) – 2,75; Zn (II) – 2,83; Ni (II) – 2.72; Ag (I) – 3.12

scholarly journals Synthesis of thiocol oligomer based on sodium tetrasulphide, epichlorhydrine and ammonium phosphate

2021 ◽  
pp. 32-37
Keyword(s):  
Differential Scanning Calorimetry ◽  
Reaction Time ◽  
Ir Spectroscopy ◽  
Ammonium Phosphate ◽  
Molar Ratio ◽  
Target Product ◽  
Optimal Conditions ◽  
Scanning Calorimetry ◽  
Molar Ratios ◽  
Main Component

The aim is to synthesize and study thiokol oligomer NEP-12 based on sodium tetrasulfide, epichlorohydrin and ammonium phosphate, which is intended for use as the main component of thiokol sealant. To achieve this goal, a thiokol oligomer based on sodium tetrasulfide, epichlorohydrin, and ammonium phosphate has been synthesized and investigated, and the optimal conditions for the synthesis of a thiokol oligomer have been determined. Research has been carried out on the influence of the molar ratios of the starting substances on the composition and physicochemical properties of the synthesized thiocol oligomer. 80 °C was taken as the optimum polycondensation temperature, the reaction time in this case is 1.5-2 hours, as a result, the yield of the target product reaches 94%. The thiokol oligomer with the best performance was obtained at a 1: 1: 1 molar ratio of sodium tetrasulfide, epichlorohydrin, and ammonium phosphate, respectively. Based on the results of IR spectroscopy and differential scanning calorimetry, a reaction for the formation of a thiokol oligomer is proposed.

Sorption of Metal Ions by New Sulfur-Containing Ionite GMA-MMA-TDGA

2017 ◽  
Vol 863 ◽  
pp. 48-52
Author(s):  
Gulzhan E. Abdraliyeva ◽  
N.A. Bektenov ◽  
N.A. Samoilov ◽  
A.K. Baidullaeva
Keyword(s):  
Sorption Capacity ◽  
Contact Time ◽  
Copper Ions ◽  
Zinc Ion ◽  
Exchange Capacity ◽  
Ion Exchanger ◽  
Static Exchange Capacity ◽  
Sorption Ability ◽  
Static Conditions ◽  
Sulfur Containing

А new polyethyleneimine sulfur-containig exchanger network structure with static exchange capacity of 0.1 N solution of HCl 4.7 mEq/g was obtained by polycondensation of glycidyl methacrylate, methyl methacrylate and phosphoric acid. Sorption of copper (II) and zinc (II) ions was studied and investigated in static conditions from model solutions of sulfates of copper and zinc, in dependence on their concentration and pH, as well as their contact time with the ion-exchanger. Found that the magnitude of the sorption capacity of the ion exchanger for ions of copper (II) at pH 3.6 CuSO4 solution is 4.03 mg / g. It has been established that zinc ion (II) is absorbed best by the sorbent at pH 4.06. In these conditions the sorption capacity of the sorbent for copper ions (II) and zinc (II) respectively equal to 0.8225mmol / g (Cu) and 0.8305mmol / g (Zn). The sorption ability new sulfur-containing ionite with respect to copper ions (II) and zinc (II) is significantly higher than for industrial ionite of KU-2x8.

Synthesis of a Ruthenium Complex Based on 2,6-Bis[1-(Pyridin-2-yl)-1H-Benzo[d]Imidazol-2-yl]Pyridine and Catalytic Oxidation of (1H-Benzo[d]-Imidazol-2-yl)Methanol to 1H-Benzo[d]Imidazole-2-Carbaldehyde with H2O2

2017 ◽  
Vol 41 (2) ◽  
pp. 88-92
Author(s):  
Shenggui Liu ◽  
Rongkai Pan ◽  
Wenyi Su ◽  
Guobi Li ◽  
Chunlin Ni
Keyword(s):  
Reaction Time ◽  
Catalytic Oxidation ◽  
Reaction Temperature ◽  
Ruthenium Complex ◽  
Reaction Conditions ◽  
Molar Ratios ◽  
Optimal Reaction

2,6-Bis[1-(pyridin-2-yl)-1H-benzo[d]-imidazol-2-yl]pyridine (bpbp), which has been synthesised by intramolecular thermocyclisation of N2,N6-bis[2-(pyridin-2-ylamino)phenyl]pyridine-2,6-dicarboxamide, reacts with sodium pyridine-2,6-dicarboxylate (pydic) and RuCl3 to give [Ru(bpbp)(pydic)] which can catalyse the oxidation of (1H-benzo[d]imidazol-2-yl)methanol to 1H-benzo[d]imidazole-2-carbaldehyde by H2O2. The optimal reaction conditions were: molar ratios of catalyst to substrate to H2O2 set at 1: 1000: 3000; reaction temperature 50 °C; reaction time 5 h. The yield of (1H-benzo[d]imidazol-2-yl) methanol was 70%.

Enhanced surface hydrophilicity of polylactic acid sutures treated by lipase and chitosan

2018 ◽  
Vol 89 (16) ◽  
pp. 3291-3302 ◽  
Author(s):  
Shuqiang Liu ◽  
Mingfang Liu ◽  
Gaihong Wu ◽  
Xiaofang Zhang ◽  
Juanjuan Yu ◽  
...  
Keyword(s):  
Reaction Time ◽  
Friction Coefficient ◽  
Surface Area ◽  
Polylactic Acid ◽  
The Body ◽  
Optimal Conditions ◽  
Absorbable Sutures ◽  
Surgical Sutures ◽  
New Type ◽  
Enhanced Surface

Polylactic acid (PLA) surgical sutures are a new type of absorbable sutures that can be degraded and absorbed in the body. However, there is high hydrophobicity for the surface of PLA sutures, which leads to poor biocompatibility and cellular affinity. In order to increase the hydrophilicity, the PLA sutures were etched by lipase firstly, and then grafted with chitosan. The results indicate that the optimal conditions of treating PLA sutures by lipase were as follows: 45℃ reaction temperature, 4.5 g/L concentration of lipase and 8 h reaction time. The sutures were etched by lipase and then formed some grooves and a number of hydroxyl (-OH) bonds, which led to increased surface area and hydrophilicity, but a drop in mass and strength. The optimal conditions of grafting chitosan onto PLA sutures were as follows: 4 h reaction time and 3 g/L concentration of chitosan. The chitosan grafted and loaded on the surface of PLA sutures, and in some areas of the sutures the chitosan reunited, which led to a rough surface and large friction coefficient. Finally, the hydrophilicity of the PLA sutures, treated by lipase and then grafted with chitosan, was greatly improved.

Removal of phenol from steel wastewater by combined electrocoagulation with photo-Fenton

2018 ◽  
Vol 78 (6) ◽  
pp. 1260-1267 ◽  
Author(s):  
Mohammad Malakootian ◽  
Mohammad Reza Heidari
Keyword(s):  
Reaction Time ◽  
Removal Efficiency ◽  
Current Density ◽  
Steel Industry ◽  
High Efficiency ◽  
Oxygen Demand ◽  
Optimal Conditions ◽  
Suitable Alternative ◽  
Steel Mills ◽  
Real Wastewater

Abstract Phenol and its derivatives are available in various industries such as refineries, coking plants, steel mills, drugs, pesticides, paints, plastics, explosives and herbicides industries. This substance is carcinogenic and highly toxic to humans. The purpose of the study was to investigate the removal of phenol from wastewater of the steel industry using the electrocoagulation–photo-Fenton (EC-PF) process. Phenol and chemical oxygen demand (COD) removal efficiency were investigated using the parameters pH, Fe2+/H2O2, reaction time and current density. The highest removal efficiency rates of phenol and COD were 100 and 98%, respectively, for real wastewater under optimal conditions of pH = 4, current density = 1.5 mA/cm2, Fe2+/H2O2 = 1.5 and reaction time of 25 min. Combination of the two effective methods for the removal of phenol and COD, photocatalytic electrocoagulation photo-Fenton process is a suitable alternative for the removal of organic pollutants in industry wastewater because of the low consumption of chemicals, absence of sludge and other side products, and its high efficiency.

scholarly journals Production of Aspartame by Immobilized Thermolysin

2019 ◽  
pp. 1232-1239
Author(s):  
Mohammed A Alsoufi ◽  
Raghad A. Aziz
Keyword(s):  
Reaction Time ◽  
Immobilized Enzyme ◽  
Bentonite Clay ◽  
Optimum Temperature ◽  
Initial Activity ◽  
Reaction Conditions ◽  
Original Activity ◽  
Ph Profile ◽  
Full Activity ◽  
Main Activity

The aim of this study was the production of aspartame by using immobilized thermolysin in bentonite clay. The yield of immobilized thermolysin in bentonite was 92% of the original enzyme amount. pH profile of free and immobilized enzyme was 7.0 and 7.5 respectively which was stable at 6.5-9.0 for 30min. The optimum temperature of both enzymes was 50°C, while they were stable at 65°C for 30min. however, they lost 52.73 and 61.72% from its main activity at 80°C respectively. Immobilized thermolysin has retained all activity within 27 days, but it kept 68.27% of initial activity when stored for 60 days at 4°C whereas, it retained a full activity after 20 continue usage. In addition, it retained 86.53% of its original activity after 30 continuing usages. The yield of produced aspartame was increased with reaction time; it was 9% after 1h and increased gradually to 100% after 10h at reaction conditions.

scholarly journals Esterification of Crude Palm Oil Using H2SO4 and Transesterification Using CaO Catalyst Derived from Anadara granosa

2017 ◽  
Vol 17 (2) ◽  
pp. 309 ◽  
Author(s):  
Nurhayati Nurhayati ◽  
Sofia Anita ◽  
Tengku Ariful Amri ◽  
Amilia Linggawati
Keyword(s):  
Reaction Time ◽  
Reaction Temperature ◽  
Palm Oil ◽  
Reaction Times ◽  
Crude Palm Oil ◽  
Process Step ◽  
Molar Ratios ◽  
One Step ◽  
Esterification Reactions ◽  
Anadara Granosa

In this study biodiesel was produced from crude palm oil through two-step processes, namely esterification reactions using homogeneous H2SO4 catalyst and transesterification using the heterogeneous base CaO catalyst derived from Anadara granosa shell. Several parameters affecting to the yields of biodiesel were investigated including the amount of the catalysts, the molar ratios of oil to methanol, reaction times and reaction temperatures. The CaO catalyst was prepared by calcining the A. granosa shells at the temperatures of 800 and 900 °C for 10 h. The as-synthesized biodiesel was analyzed using GC and its characteristics were determined and the results were compared to Standard National for Biodiesel (SNI 04-7183-2006). The optimum condition for the esterification process (step 1) was as follows: reaction temperature of 65 °C, reaction time of 3 h and mol ratio of oil to methanol 1:24. For the transesterification (step 2) the optimum conditions were attained using the catalyst weight 3%, reaction temperature of 60 °C, reaction time of 3 h, mole ratio of oil/methanol 1:6 and the catalyst calcination time of 10 h with the conversion of 87.17%. This biodiesel yield by the two-step processes was higher (2.7%) than that using only one-step process (transesterification).

scholarly journals Formation of conjugated double bonds in soybean oil with iodine as a catalyst

2016 ◽  
Vol 81 (2) ◽  
pp. 141-151 ◽  
Author(s):  
Jie Yan ◽  
Jinlan Yang ◽  
Rifu Yang ◽  
Haifen He ◽  
Qihai Liu ◽  
...  
Keyword(s):  
Linoleic Acid ◽  
Reaction Time ◽  
Soybean Oil ◽  
Linolenic Acid ◽  
Conversion Rate ◽  
Raw Material ◽  
Catalyst Loading ◽  
Optimal Conditions ◽  
Trans Isomers ◽  
High Conversion Rate

A method for the iodine-catalyzed conjugation of soybean oil was developed, and the conjugated product was analyzed by UV, IR, and 1H NMR. The results indicated that the optimal conditions for conjugation included a temperature of 180?C, a catalyst loading of 0.5 wt.% and a reaction time of 3 h, at which the concentration of conjugated linoleic acid was 1.51 mol L-1, with 92 % conversion, the CLNA reached 0.225 mol L-1 when the temperature was 130?C, a catalyst loading of 0.5 wt.%, and a reaction time of 3 h with a conversion rate of 99.9 %. The reaction predominantly produced trans-trans, trans-cis and cis-trans isomers. It was also revealed that the conjugation of linolenic acid was much faster than that of linoleic acid. The method possessed the advantages of a short procedure, a high conversion rate, and no methyl esterification of the raw material, and it was an environmentally friendly technology that does not use solvents.

scholarly journals The development of technology for production of zeolites from fly-ash from Troitskaya power plant

2021 ◽  
Vol 8 (1) ◽  
pp. 20218111
Author(s):  
V. A. Snegirev ◽  
V. M. Yurk
Keyword(s):  
Fly Ash ◽  
Power Plant ◽  
Pore Diameter ◽  
Silicon Oxide ◽  
Exchange Capacity ◽  
Static Exchange Capacity ◽  
Average Pore ◽  
Hydrochemical Synthesis ◽  
Bet Method ◽  
Zeolite Production

The study examines the technology of processing fly ash from Troitskaya power plant for the production of zeolite. The paper presents the results of laboratory studies evaluating the suitability of fly ash from Troitskaya power plant for the production of zeolites and the development of the zeolite production process. Fly ash contains a small amount of heavy metals that can complicate processing, but contains a large amount of silicon oxide. The technology consists of high-temperature alkaline activation of fly ash and hydrochemical synthesis. The resulting powder has a specific surface area of 89.7 m2/g, determined by the BET method, and an average pore diameter of 0.345 μm. The static exchange capacity was 220 mg/g.

Sorption of Uranium (VI) Ions by a Sorbent Based on a Copolymer of Maleic Anhydride with Styrene Modified by N, Nand#39;-diphenylguanidine

2020 ◽  
Vol 42 (3) ◽  
pp. 413-413
Author(s):  
Fidan Bahmanova Fidan Bahmanova ◽  
Sevinj Hajiyeva Sevinj Hajiyeva ◽  
Elnara Alirzaeva Elnara Alirzaeva ◽  
Nazim Shamilov and Famil Chyragov Nazim Shamilov and Famil Chyragov
Keyword(s):  
Sorption Capacity ◽  
Ionization Constants ◽  
Saturation Curve ◽  
Optimal Conditions ◽  
Sorption Equilibrium ◽  
Ionogenic Groups ◽  
Chelating Sorbent ◽  
Mineral Acids ◽  
Degree Of Extraction ◽  
Sorption Time

In this paper the results of a study on the extraction and concentration of micro-quantities of uranium (VI) with a polymeric chelating sorbent with fragments of N, N and#39;diphenylguanidine is discussed. There was studied a static sorption capacity on K+ ions ((SSC = 9.3 mmol / g) and there were determined the ionization constants of ionogenic groups ( =3.97; =8.47) by potentiometric titration. The optimal conditions of the sorption of elements (pHopt, sorption time - τ, the influence of ionic strength - μ) were determined by the dependence of the sorption capacity (SC, mg/g) on the parameter being studied; the sorption capacity of the sorbent (SC) was determined from the saturation curve constructed under optimal sorption conditions. The maximum degree of extraction of uranium by sorbents is achieved from solutions with pH 5. Sorption equilibrium is achieved within 2 hours of contact of the solution with the sorbent. With an increase in the concentration of the uranyl ion in the solution, the amount of the sorbed metal increases, and at a concentration of 8•10–3 mol/l, it becomes maximal (pH = 5, = 8•10–3 mol/l, Vgen = 20 ml, msorb. = 0.05 g, SC = 1258 mg/g). Limits of detection (3, n=20) are 13.9 ng/ml. The effect of various mineral acids(HClО4, H2SО4, HNО3, HCl) with the same concentrations on the desorption of uranium (VI) from the sorbent was studied. The developed technique was applied to determine uranium in oil sludge.

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