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In order to improve the utilization value of the erythritol mother liquor, the separation and purification of the erythritol mother liquor was selected in this study. The selected chromatographic separation programme for erythritol crystallizing mother liquor is as follows: Firstly, erythritol is resolved from mannitol and arabitol with DTF-01Ca (Suqing Group) resin and then mannitol is resolved from arabitol with 99Ca/320 (Dowex) resin. At the same time, the chromatographic conditions of the DTF-01Ca (Suqing Group) and 99Ca/320 (Dowex) resins were optimized, resulting in an optimal separation temperature and mobile phase flow rate of 70 °C, 10 ml/min. On this basis, a single-column chromatographic model was used to calculate the TD model parameter ( N ) and the mass transfer coefficient ( k m ) of the separation of erythritol mother liquor by DTF-01Ca (Suqing Group) and 99Ca/320 (Dowex) resins. The adsorption isotherms, TD model parameter ( N ) and the mass transfer coefficient ( k m ) provides data references for the design and operation of the simulated moving beds (SMB) separation system for the industrial-scale separation of erythritol crystallizing mother liquor. [ABSTRACT FROM AUTHOR]

In industrial crystallization, all impurity species need to be removed, regardless of the kind of impurity present in the raw materials. Removing the mother liquor is required because a crystal cake with mother liquor holdup is frequently formed by crystalline particles during solid-liquid separation in suspension-type melt crystallization. This study aims to make clear the relationship between the mother liquor holdup and the characteristics of the crystal cake, and the difference in residue behaviors of impurities based on the new concept for understanding the mother liquor holdup. As a result, the initial mother liquor holdup depended on the specific surface area of the crystal cake. Investigating the residue behavior of each impurity suggests that the impurity-based inclusion factors were different from the solvent-based inclusion factor depending on the kind of impurity. Furthermore, a certain impurity had a specific surface area dependence of the residual amount of impurity.

Direct synthesis of light olefins from syngas (STO) using bifunctional catalyst composed of oxide and zeolite has attracted extensive attention in both academia and industry. In this study, we present a facile post-treatment approach to obtain hierarchical SAPO-34 by treating the crystallized product in mother liquor at low temperature. The physical and chemical properties of the resulting molecular sieves were characterized by XRD, SEM, TEM, N2 adsorption–desorption, XRF and NH3-TPD. The obtained hierarchical SAPO-34 were mixed with ZnCrAlOx oxide to prepare the bifunctional catalyst, and the catalytic performance for direct conversion of syngas to light olefins was examined. Compared with the bifunctional catalyst obtained from the SAPO-34 molecular sieves without post-treatment, the bifunctional catalyst with hierarchical SAPO-34 obtained by mother liquor post-treatment showed enhanced performance with higher selectivity of light olefins. Importantly, the bifunctional catalyst with hierarchical SAPO-34 has a good catalytic stability with no obvious deactivation over 100 h of testing. The enhanced catalytic performance of the bifunctional catalyst with hierarchical SAPO-34 could be attributed to the hierarchical structure of SAPO-34 that can increase the rate of mass transfer to avoid further hydrogenation and conversion of olefin products on the catalyst, thus could improve the selectivity of C2–C4 olefins. [ABSTRACT FROM AUTHOR]

Background. A by-product of copper production of Almalyk MMC JSC is copper sulfate GOST 19347-99. One of its impurities is nickel. Purpouse. Development of a method for extracting nickel from copper sulphate. Methodology. Object of study: solutions and crystallization product of copper sulphate of the sulphate shop. The composition of the phases was determined by the method of physicochemical analysis according to Skreinemakers, the analysis of samples was performed on a Perkin-Elmer 3030B AAS. Originality. The possibility of extracting impurity ions of nickel (II) from the crystallization solution of copper sulphate by fractional crystallization and selective sorption has been revealed. Findings. Methods have been developed for the precipitation of Ni (II) ions in the form of nickel carbonate with conversion to nickel vitriol; fractional crystallization of copper sulphate with precipitation from mother liquors of nickel sulphate, selective sorption of copper on PuroliteS-960 resin in the presence of Ni(II) ions. [ABSTRACT FROM AUTHOR]

Nanoscale SAPO-34 molecular sieves were synthesized by adding different types of seed into hydrothermal synthesis systems with tetraethylammonium hydroxide (TEAOH) and triethylamine (TEA) & tetraethylammonium bromide (TEABr) as templates. The effects of different types of template and seed on the crystal structure, morphology, grain size and acidity of the molecular sieves were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), N2 isothermal adsorption–desorption and ammonia temperature-programmed desorption (NH3-TPD). The methanol-to-olefins (MTO) reaction performance of the synthesized samples was investigated in a fixed-bed reactor. The results showed that crystalline supernatant and seed soaking solution could be used as liquid seeds to assist in the synthesis of SAPO-34 molecular sieves with a lamellar structure. The yield of SAPO-34 synthesized by seed increased from 38.64 to 59.68%, and the methanol conversion rate was significantly improved as compared with that of SAPO-34 synthesized without seed. The nano-thickness of SAPO-34 synthesized with TEA&TEABr instead of TEAOH as template decreased from 100–150 to 40–50 nm, and the lifetime increased from 360 to 400 min with the original yield kept constant. Nanoscale SAPO-34 molecular sieves were synthesized by adding different types of seed into the hydrothermal synthesis system. The addition of seed into the initial gel during the synthetic process can facilitate the nucleation process and increase the crystallization rate effectively. [ABSTRACT FROM AUTHOR]

The possibility of the rhenium recovery by sorption onto a fluoroplastic-containing composite from the mother (process) liquor after precipitation of the cobalt–nickel concentrate obtained by complex processing of nickel-based rhenium-containing superalloy waste was examined in batch experiments. The isotherms of the rhenium sorption from a model solution and the mother liquor were obtained by the variable-volume method. The Henry constant in rhenium sorption from the mother liquor was 2100 ± 600 mL g–1. The rhenium sorption kinetics was studied in batch experiments. Mathematical processing of the data of the integral kinetic curves using the kinetic and diffusion models showed that the highest coefficient of determination (R2 = 0.999) was observed when using the pseudo-second-order model formally confirming certain contribution of the chemical reaction to the process. The rate constants calculated using the pseudo-second-order model were (1.7–2.8) × 10–3 g mg–1 min–1. Analysis by the external and internal diffusion models showed that the rhenium sorption onto the fluoroplastic-containing carbon composite occurred by the mixed-diffusion mechanism, with the contribution of the internal diffusion increasing with an increase in the concentration of ReO4– ions on the composite pore surface. The sorption properties of the carbon composite were stable in three cycles of rhenium sorption–desorption from the mother (process) liquor. [ABSTRACT FROM AUTHOR]

Protein crystallization was discovered by chance nearly 200 years ago and was developed in the late nineteenth century as a powerful purification tool, and a demonstration of chemical purity. The crystallization of proteins, nucleic acids, and large biological complexes, such as viruses, depends on the creation of a solution that is supersaturated in the macromolecule, but exhibits conditions that do not significantly perturb its natural state. Supersaturation is produced through the addition of mild precipitating agents such as neutral salts or polymers, and by manipulation of various parameters that include temperature, ionic strength, and pH. Also important in the crystallization process are factors that can affect the structural state of the macromolecule, such as metal ions, inhibitors, cofactors, or other conventional small molecules. A variety of approaches have been developed that combine the spectrum of factors that effect and promote crystallization, and among the most widely used are vapor diffusion, dialysis, batch, and liquid-liquid diffusion. Successes in macromolecular crystallization have multiplied rapidly in recent years due to the advent of practical, easy-to-use screening kits, and the application of laboratory robotics.

AlPO4-5 with an AFI topology membrane on an a-alumina substrate has been fabricated continuously, without defects, and with high intergrowth. By using traditional hydrothermal methods in diluted mother liquor, an AlPO4-5 membrane has been produced by a simple second growth synthesis. Scanning electron microscopy (SEM) revealed no defects in the prepared supporting film, and X-ray (XRD) diffraction confirmed the layer of molecular sieve AlPO4-5 on the porous support of α-alumina. In this study, various synthesis parameters were systematically examined. Based on H2, He, N2, CO2, and SF6 permeance results, the supported membranes display Knudsen diffusion behavior, and the membrane’s pervaporation properties of organic compounds (n-hexane, o-xylene, and TIPB) show minimized defects, verifying their high quality.

Fabrication of hierarchical porosity in microporous zeolites is a key to overcoming the inherent mass‐transfer limitation and to improving the molecular accessibility to the active sites. The present study reports a facile and cost‐effective etching strategy based on crystal metastability to construct a hierarchical SAPO‐34 (CHA‐type) zeolite. The hierarchical SAPO‐34 with high crystallinity is obtained conveniently via an extended hydrothermal treatment without using any additional chemicals. The crystal etching is triggered by the metastability of SAPO‐34 in the mother liquor. The hierarchical characteristics of etched SAPO‐34 are found dependent on the crystallization‐dissolution process controlled by the synthesis temperature and time. The products are systematically investigated by complementary characterization methods providing information on the textural properties and chemical environments of framework atoms. The resultant hierarchical zeolites exhibit improved diffusion and accessibility to the active sites in the micropores. Consequentially, the hierarchical SAPO‐34 zeolite shows remarkably enhanced catalytic performance in the methanol‐to‐olefin (MTO) reaction, compared with its microporous counterpart. The present approach to hierarchical zeolites can be extended to tailor the properties of other zeo‐types. [ABSTRACT FROM AUTHOR]

Dihomo-γ-linolenic acid (DGLA; C20:3 n-6) is expected to dominate the functional ingredients market for its role in anti-inflammation and anti-proliferation. The DGLA production by the engineered strain of Aspergillus oryzae with overexpressing Pythium Δ6-desaturase and Δ6-elongase genes was investigated by manipulating the nutrient and fermentation regimes. Of the nitrogen sources tested, the maximum biomass and DGLA titers were obtained in the cultures using NaNO3 grown at pH 6.0. For establishing economically feasible process of DGLA production, the cost-effective medium was developed by using cassava starch hydrolysate (CSH) and NaNO3 as carbon and nitrogen sources, respectively. The supplementation with 1% (v/v) mother liquor (ML) into the CSH medium promoted the specific yield of DGLA production (YDGLA/X) comparable with the culture grown in the defined NaNO3 medium, and the DGLA proportion was over 22% in total fatty acid (TFA). Besides, the GLA was also generated at a similar proportion (about 25% in TFA). The mathematical models of the cultures grown in the defined NaNO3 and CSH/ML media were generated, describing that the lipid and DGLA were growth-associated metabolites corresponding to the relevant kinetic parameters of fermentations. The controlled mode of submerged fermentation of the engineered strain was explored for governing the PUFA biosynthesis and lipid-accumulating process in relation to the biomass production. This study provides an informative perspective in the n-6 fatty acid production through physiological manipulation, thus leading to a prospect in viable production of the DGLA-enriched oil by the engineered strain.

The electro-Fenton (EF) process was applied to treat mother liquor of gas field wastewater (ML-GFW). The Fe-Fe electrodes were used and H2O2 was added to the EF system. Effect of initial pH on chemical oxygen demand (COD) removal efficiency, specific electrical energy consumption (SEEC), specific electrode plate consumption (SEPC) and organic matter removal mechanism was investigated. The results showed that COD removal efficiency reached the maximum (71.9%) at initial pH of 3 after reaction for 3 h. Besides, considering with the SEEC and SEPC, pH of 3 was also the best choice, at which SEEC was 4.7 kW h kgCOD−1, SEPC was 0.82 kgFe kgCOD−1. Organic matter removal was achieved by two ways: oxidation and flocculation, and oxidation played a major role. With the analysis of GC-MS, the possible degradation pathways of the representative contaminants in the ML-GFW were given.

Dihomo-γ-linolenic acid (DGLA; C20:3 n -6) is expected to dominate the functional ingredients market for its role in anti-inflammation and anti-proliferation. The DGLA production by the engineered strain of Aspergillus oryzae with overexpressing Pythium Δ6-desaturase and Δ6-elongase genes was investigated by manipulating the nutrient and fermentation regimes. Of the nitrogen sources tested, the maximum biomass and DGLA titers were obtained in the cultures using NaNO3 grown at pH 6.0. For establishing economically feasible process of DGLA production, the cost-effective medium was developed by using cassava starch hydrolysate (CSH) and NaNO3 as carbon and nitrogen sources, respectively. The supplementation with 1% (v / v) mother liquor (ML) into the CSH medium promoted the specific yield of DGLA production (Y DGLA / X ) comparable with the culture grown in the defined NaNO3 medium, and the DGLA proportion was over 22% in total fatty acid (TFA). Besides, the GLA was also generated at a similar proportion (about 25% in TFA). The mathematical models of the cultures grown in the defined NaNO3 and CSH/ML media were generated, describing that the lipid and DGLA were growth-associated metabolites corresponding to the relevant kinetic parameters of fermentations. The controlled mode of submerged fermentation of the engineered strain was explored for governing the PUFA biosynthesis and lipid-accumulating process in relation to the biomass production. This study provides an informative perspective in the n- 6 fatty acid production through physiological manipulation, thus leading to a prospect in viable production of the DGLA-enriched oil by the engineered strain. [ABSTRACT FROM AUTHOR]

In order to alleviate the sulfate accumulation in uranium hydrometallurgy process, the sulfate accumulating path was studied and a new elution process was proposed. The eluate composition as a function of eluent volume during the conventional and new elution process was studied. The result showed that pre-elution of saturated resin with 0.5–0.8 BV (bed volume) mother liquor was beneficial to the discharge of accumulated sulfate and could alleviate the accumulation of sulfate. Field tests showed that the new process ensured more stable production and reduced the amount of wastewater. Finally, the mechanism of the pre-elution process was analyzed. [ABSTRACT FROM AUTHOR]

Polyaluminum phosphoric sulfate (PAPS), which is a composite coagulant, was prepared using SAPO-34 mother liquor that was obtained from the process of synthesizing SAPO-34 molecular sieve. After the pretreatment of the SAPO-34 mother liquor, 80.50 % of the triethylamine in the mother liquor was recycled by fractional distillation and the residual triethylamine was oxidized and decomposed by ozone. Furthermore, during the preparation of PAPS, the effects of [P]/[Al], [OH]/[Al] molar ratios, and reaction temperature were examined, and the optimum preparation conditions were determined by response surface methodology. Results showed that the optimum PAPS preparation conditions were n(P)/n(Al) = 0.25, n(OH)/n(Al) = 1.05, and temperature of 85 °C. In addition, the structure and morphology of PAPS were characterized by scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD), and the coagulation performances were evaluated by kaolinite synthetic water treatment. The results indicate that complex compounds are formed in the synthesis of PAPS. Finally, on comparison with PAC and Al 2 (SO 4) 3 ·18H 2 O, PAPS exhibits better coagulation performance in removing turbidity and total phosphorus, when the dosage is 40 mg/L. [ABSTRACT FROM AUTHOR]

The corrosion resistance of SAF 2507 duplex stainless steel and 254 SMO superaustenitic steel is studied in aggressive sulfuric-acid solutions (mother liquor) from sulfate departments; in aggressive media from arsenic–soda desulfurization; and in coke-shop media (from the quenching car and quenching tower). Gravimetric tests are conducted in accordance with State Standard GOST 9.908–85. The research is conducted both at coke plants and in the laboratory. It follows from gravimetric tests and cyclic volt–ampere measurements that these materials are highly resistant to point and pitting corrosion in the aggressive media considered. Such corrosion processes are provoked by the presence of activators (H2S, HCN, HCNS, and Cl–). These findings are confirmed by the considerable life of passive films of molybdenum-bearing steel. Research shows that SAF 2507 (#Kh25H7AM4#) duplex steel and Avesta 254S MO superaustenitic steel are highly resistant to point and slot corrosion and outperform the ordinary #0Kh23N28M3D3T, 10Kh17N13M2T,# and #12Kh18M10T# steels used for heat-exchanger production. [ABSTRACT FROM AUTHOR]

Background. In the production of acetaldehyde, Navoiazot JSC uses the "Cadmium Calcium Phosphate Catalyst (CCP-N)" TU113-03-00209510-108-2006, whose service life is 6 months. A technology has been developed for the processing of spent CCP-N catalyst with the return of cadmium to a new cycle of its synthesis. To ensure its analytical control, an express and accurate method for the analysis of cadmium in technological solutions at different stages of this process is required. Purpose: development of methods for analytical control of the process of regeneration (recycling) of cadmium from spent CCP catalyst. Methodology. The mass concentration of cadmium was determined by voltammetry on a rotating glass fiber cathode with a mercury amalgam (polarograph ABC-1.1) and atomic absorption (PEA Analyst 200). Originality. A technique has been developed for determining the cadmium content in technological solutions for processing spent CCP-N catalyst using amalgam polarography with accumulation as an alternative method for determining cadmium, a fiery version of atomic absorption spectroscopy is proposed. Findings. When processing the catalyst CCP-N, the resulting cadmium-containing technological solutions are mother liquors (after separation of calcium and cadmium); the solutions before and after sorption of cadmium are precisely controlled by polarography, which is confirmed by the data of their adsorption-spectrophotometric determination. [ABSTRACT FROM AUTHOR]

The rational disposal of Li 2 CO 3 mother liquor is especially critical with the rapid increase in lithium consumption. Most of the current processes are based on solvent extraction, which has still not been applied to practical industry due to their drawbacks. In this paper, a novel process for selective extraction of lithium from high-sodium concentration Li 2 CO 3 mother liquor by NaF precipitation was proposed. 91.3% of lithium precipitated as LiF under the optimal conditions, such as NaF dosage of 1.1 times theoretical amount, temperature of 30 °C, and time of 2 h. Subsequently, the precipitation products were converted by Ca(OH) 2. The conversion of LiF reached 89.9% and the liquid product obtained was LiOH solution with 7.5 g/L Li. The separation factor of Li/Na in the whole process reached 377. This novel process is an efficient, clean, and short process that provides a new idea for the selective synthesis LiOH from high-sodium concentration Li 2 CO 3 mother liquor. • The selective recovery of lithium from Li 2 CO 3 mother liquor was achieved. • 91.3% of the lithium precipitated as LiF under the optimal conditions. • The conversion of LiF reached 89.9% and LiOH solution with 7.5 g/L Li was obtained. • The separation factor of Li/Na in the whole process reached 377. • It is an efficient, clean, and short process. [ABSTRACT FROM AUTHOR]

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For the first time it is proposed to produce lithium hydroxide monohydrate as a primary derivative product from hydromineral raw materials. This technology is based on the primary lithium concentrate obtained by enriching the lithium-bearing brines and concentrating by the combined method. The produced concentrate is a pregnant lithium chloride solution which is subjected to the electrochemical conversion: LiCl ⋅ LiOH. The lithium hydroxide monohydrate crystals are extracted from the lithium hydroxide solution and, after washing, they correspond to the LGO-1 brand. [ABSTRACT FROM AUTHOR]

In the recovery process of rare earth (RE) from the weathered crust elution-deposited rare earth ore, ammonium sulfate is used as the leaching liquor to leach RE, and then the leachate containing RE3+ can be precipitated by oxalic acid and the RE oxalate precipitation mother liquor is reused for RE leaching process after removing the residual oxalic acid by precipitation with calcium hydroxide. However, the reuse process of precipitation mother liquor cannot proceed in the strong acid and alkali restricted areas and the discharge of mother liquor which contains a large amount of ammonium salt will cause ammonia-nitrogen waste and pollution. In order to realize the reuse of the precipitation mother liquor in this area, the direct reuse of RE oxalate precipitation mother liquor for RE leaching was investigated in this study. The RE oxalate precipitation process and the RE leaching process with oxalic acid were studied. The results showed that the residual oxalic acid concentration in the mother liquor can be controlled lower than 0.8 g/dm³ at pH 2-3 when the RE concentration in the leachate was 0.1- 1.5 g/dm³ and the RE precipitation rate reached to 94%. In addition, RE leaching efficiency was up to 90% while the oxalic acid concentration in the prepared mother liquor was 0.2-0.8 g/dm³, pH 2-3. Therefore, the precipitation mother liquor with oxalic acid concentration less than 0.8 g/dm³ could be directly reused for RE leaching. However, considering the different performance of RE ores, the recommended oxalic acid concentration in the direct used precipitation mother liquor was lower than 0.6 g/dm³. [ABSTRACT FROM AUTHOR]

Mother liquor (ML) is monosodium glutamate by‐product and contains much crude protein (CP). The objective of this study was to investigate the effect of supplementation of two types of MLs having different chemical compositions on in vitro ruminal fermentation characteristics. ML1 had 74% organic matter (OM) and 70% CP and ML2 had 85% OM and 83% CP on a dry matter (DM) basis. The experiments were conducted using 0.5 gDM rolled barley or ryegrass straw as substrates. Urea and freeze‐dried MLs were added at three levels of nitrogen to be isonitrogenous. The ML1 treatment increased gas production compared with the ML2 treatment in barley substrate condition (p < 0.05). The supplementary ML2 increased gas production compared with the supplementary urea, and the digestibilities of DM and neutral detergent fiber expressed exclusive of residual ash (NDFom) were higher for the supplementary ML2 than for the supplementary ML1 in straw substrate condition (p < 0.05). In both the conditions, ammonia nitrogen concentrations of the ML1 and ML2 treatments were lower than that of the urea treatment (p < 0.05). The results indicated that the supplementary ML1 and ML2 activated in vitro ruminal fermentation particularly in concentrate and roughage substrate conditions respectively. [ABSTRACT FROM AUTHOR]

ZIF-8, ZIF-L, ZIF-7 and ZIF-67 were synthesized from fresh and recycled synthesis solutions. ZIF-8, ZIF-L and ZIF-7 includes Zn 2+ , while ZIF-67 includes Co 2+ . ZIF-7 was synthesized in dimethyl formamide, while the others in water. The organic linker was 2-methyl imidazole for ZIF-8, ZIF-L and ZIF-67, and benzimidazole for ZIF-7. The recycling was proceeded two steps for each type of ZIF. For the synthesis in the recycled solutions, the pH and the metal ion content of the mother liquor should be adjusted for a successful synthesis. All synthesis using fresh and recycled solutions resulted in highly crystalline ZIFs. The crystal morphology, N 2 adsorption capacity and thermal behavior of ZIFs from recycled solutions were similar to those obtained from the fresh solution. The recycling procedures improved the efficiency of crystallization such that 0.36 g ZIF-7/g organic linker was obtained after two recycling steps, although only 0.16 g ZIF-7/g organic linker can be obtained after single step synthesis using fresh solution. From an environmental perspective, the developed procedures allowed to consume a great extent of organic linker used for synthesis, therefore the amount of waste organic linker was reduced. [ABSTRACT FROM AUTHOR]