Alum Research Articles

Synthesis and long‐term stability of acrylic acid and N, N‐methylene‐bis‐acrylamide radiation grafted polypropylene fibers

AbstractNew carboxyl ion‐exchange fibers prepared by acrylic acid (AA) and N, N‐methylene‐bis‐acrylamide (MBAA) monomer grafting to polypropylene (PP) fibers based on the method of γ‐rays pre‐irradiation in air followed by a Mohr's salt redox initiation of grafting reaction were studied. Grafting degree, homopolymer quantity, monomer conversion and grafting efficiency were determined. FTIR spectroscopy was used to establish the nature of the grafted fibers. The thermal stability of the materials was investigated based on DSC analysis in N2/O2 mixture. The long‐term stability during 6–8 years of storage was examined by the measurement of the tensile strength and the elongation at break of the fibers, and the chemical oxygen demand in water extracts as well as in the oxygen uptake experiments. The influence of some factors on the useful life of the grafted fibers was studied: a MBAA cross‐linking, exposure to day light, the Fe (III) residue presence, a grafting reaction temperature. It was found that small amounts of the adsorbed Fe (III) ions increase the deterioration rate of the grafted fibers, while small amounts of MBAA delay this negative process.

Characterization of soy protein hydrolysates and influence of its iron content on monoclonal antibody production by a murine hybridoma cell line.

A challenging aspect with the use of protein hydrolysates in commercial manufacturing processes of recombinant therapeutic proteins is their impacts on the protein production due to a lack of understanding of batch-to-batch variability. Soy hydrolysates variability and its impact on fed-batch production of a recombinant monoclonal antibody (mAb) expressed in Sp2/0 cells were studied using 37 batches from the same vendor. The batch-to-batch variability of soy hydrolysates impacted cell growth, titer and product quality. Physicochemical characterization of batches confirmed that soy hydrolysates are mainly a source of amino acids and peptides containing lower amounts of other components such as carbohydrates and chemical elements in cell culture media. Soy hydrolysates composition of different batches was consistent except for trace elements. Statistical analyses identified iron as a potential marker of a poor process performance. To verify this correlation, two forms of iron, ferric ammonium citrate and ferrous sulfate, were added to a batch of soy hydrolysates associated to a low level of iron during cell culture. Both forms of iron reduced significantly cell growth, mAb titer and increased level of the acidic charge variants of the mAb. Consequently, trace element composition of soy hydrolysates or of all incoming raw materials might lead to significant impacts on process performance and product quality and therefore need to be tightly controlled.

Synthesis and characterization of Graphene Oxide-Ammonium Ferric Sulfate composite for the removal of dyes from tannery wastewater

The leather processing industry is currently facing numerous environmental pollution challenges. Dyes are known as one of the most significant causes for water pollution. Thus, the present work is designed to tackle this issue via preparation of different composite comprising both graphene oxide and ammonium ferric sulfate, donated as GO-AFS. Results obtained via FTIR, TGA, XRD and SEM tools confirmed the facile preparation of GO-AFS composite having good thermal stability and exhibited rough and porous surface with no clear edges. The adsorption efficiency of the as-prepared GO-AFS composite was successfully examined against two commercial dyes, namely anionic dye Basic Black 7 (BB7) and cationic dye Acid Black 210 (AB210) together with specific tannery dye wastewater. The findings also ascertained that the color removal for BB7 was noticed to be mostly 100% within 2 min by GO-AFS adsorbent at 10 mg (0.1 g/L), while the color removal concentration at pH~7 was up to 700 ppm. In addition, the color removal performance of AB210 was also detected at approximately 100% by 12 mg (0.12 g/L) of GO-AFS within 3 min when the dye concentration at pH~4 was up to 400 ppm. Regarding the removal of real tannery dye from wastewater, it was also observed that the efficacy of GO-AFS as adsorbent reached 100%. Within the second cycle, the adsorption potential of recycled GO-AFS was restored by nearly 100% and this percentage decreased to 95.4% in the third cycle. In view of these findings, it can be concluded that the prepared GO-AFS composite can be considered as an excellent candidate for eradication of pollutants or contamination from tannery wastewater instead of the conventional high-cost adsorbents.

Proteomics analysis of the bio-functions of Dregea sinensis stems provides insights regarding milk-clotting enzyme

Dregea sinensis (D. sinensis) stems have traditionally been used as milk coagulant in Dali of Yunnan Province, China. In this study, proteomics was used to investigate the bio-functions of D. sinensis stem proteins, leading to the purification and identification of the milk-clotting enzyme. A total of 205 proteins mainly involved in the catalytic and metabolic processes were identified, of which 28 proteins exhibited hydrolase activity. Among the 28 proteins, we focused on two enzymes (M9QMC9 and B7VF65). Based on proteomics, a cysteine protease (M9QMC9) with a molecular weight of 25.8 kDa and milk-clotting activity was purified from D. sinensis stems using double ammonium sulfate precipitation and was confirmed using liquid chromatography-mass spectrometry (LC-MS/MS). The milk-clotting temperature using the purified enzyme was around 80 °C (specific activity at 314.38 U/mg), and it was found to be stable in the pH range of 6–9 in NaCl concentration of <0.8 mol/L. These findings indicated that the enzyme isolated from D. sinensis stems has potential in the dairy and food sectors, especially in the cheese-making industry.

Fluoride removal using Alum & PACl in batch & continuous modewith subsequent microfiltration

In this study, defluoridation efficiency by aluminium sulphate (alum) and polyaluminium chloride (PACl) were compared for recommended Nalgonda dose (100%) and 80 % of this dose in both batch and continuous modes. The residual turbidity was found to be higher in case of alum as compared to PACl with 80 % dose representing lesser efficient settling of suspensions, which primarily comprise alumino-fluoro complexes that result in high residual aluminium in the treated water and this was confirmed by TEM and Zeta analysis. Moreover, the application of PACl also resulted in much lesser addition to the TDS and also required lesser lime for pH compensation due to its lower acidity. Hence this reduced dose was recommended for defluoridation. It was also observed that in case of alum, residual aluminium in treated water was 0.88 mg/L (100% dose) & 0.72 mg/L (80% dose) and in case of PACl, it was 0.52 mg/L(100% dose) & 0.41 mg/L(80% dose). After subsequent microfiltration, residual aluminium was 0.28 & 0.21 mg/L for 100 % & 80 % dose respectively and in case of alum and in case of PACl, it was 0.16 & 0.11 for 100% & 80 % dose respectively, which conform to the Al standards(<0.2 mg/L).

Give Alums Clear‐Cut Membership Options

Give Alums Clear‐Cut Membership Options

KLa(SO4)2–CaSO4 System

Solid-state reactions have been used to study phase relations between KLa(SO4)2 and CaSO4 at temperatures in the range 600–800°C. The phase diagram of the KLa(SO4)2–CaSO4 system has been constructed using thermogravimetry and X-ray diffraction results. The system has been shown to contain neither intermediate compounds nor solid solutions. The KLa(SO4)2 double sulfate decomposes at a temperature of 970°C. An endothermic peak at a temperature of 900°C is observed over the entire composition range and corresponds to a eutectic line. Differential thermal analysis curves of the constituent sulfates KLa(SO4)2 and CaSO4 do not show this peak. The largest magnitude of the 900°C endotherm corresponds to a eutectic containing 70 mol % CaSO4.

Role of ferritinophagy in cystine deprivation-induced cell death in glioblastoma cells

Ferroptosis is a form of cell death caused by iron-dependent lipid peroxidation. Cancer cells increase cystine uptake for the synthesis of glutathione (GSH), which is used by glutathione peroxidase 4 to reduce lipid peroxides. Here, we report that cystine deprivation in glioblastoma cells, but not inhibition of GSH synthesis by l-buthionine sulfoximine (BSO), induces ferroptosis. We found that cystine deprivation decreased the protein levels of ferritin heavy chain FTH1, whereas it was increased by BSO treatment. The lysosome inhibitor bafilomycin A1 or deletion of nuclear receptor coactivator 4 (NCOA4) inhibited cystine deprivation-induced decrease in FTH1 protein levels and cell death. In addition, cystine deprivation induced microtubule-associated protein light chain 3 (LC3)-II protein accumulation, suggesting that cystine deprivation induces ferritinophagy. BSO causes cell death when glioblastoma cells are treated with iron inducers, ferrous ammonium sulfate or hemin. On the other hand, cystine deprivation-induced degradation of FTH1 and cell death required glutamine. This study suggests that ferritinophagy, in addition to GSH depletion, plays an important role in cystine deprivation-induced ferroptosis in glioblastoma cells.

Новые данные по вооружению терракотовой армии (технологический аспект)

This article presents the results of studying protection methods against corrosion in bronze weapons which were found in the Mausoleum of Qin Shihuangdi. Even during the first season of excavations, well-preserved weapons with traces of chromium on the surface were discovered. Based on these findings, it was suggested that the Qin artisans knew the chromium plating process, when protective film was applied by immersing a bronze item in a container with solution of chromic acid salts. However, this technology is very complicated; it was fully mastered only in the early 20th century. Moreover, less than a dozen weapons were presented as examples of such a technology already in the Qin period (late 2nd century BC), which is not enough for such large-scale conclusions. Therefore, nowadays, an international team of scholars led by M. Martinon-Torres attempted to find a solution to this problem. As a result of their multidisciplinary studies, it has been established that traces of chromium on the surface of weapons are not directly associated with its good preservation. Particles of this metal were contained in lacquered fittings (scabbard, overlays on the handle, etc.), from where they penetrated into the composition of bronze. In the composition of lacquer, chromium ions appeared from treatment with chrome alum, well known to the Qin leatherworkers who could also use it for accelerating polymerization of lacquer tree sap. As far as really good preservation of bronze weapons found in the excavations is concerned, it was explained primarily by specific features of soil in the Mausoleum area (low acidity, fine dispersion, small amount of organic matter, etc.).

Thermodynamics of the double sulfates Na2M2+(SO4)2·nH2O (M = Mg, Mn, Co, Ni, Cu, Zn, n = 2 or 4) of the blödite-kröhnkite family.

The double sulfates with the general formula Na2M2+(SO4)2·nH2O (M = Mg, Mn, Co, Ni, Cu, Zn, n = 2 or 4) are being considered as materials for electrodes in sodium-based batteries or as precursors for such materials. These sulfates belong structurally to the blödite (n = 4) and kröhnkite (n = 2) family and the M cations considered in this work were Mg, Mn, Co, Ni, Cu, Zn. Using a combination of calorimetric methods, we have measured enthalpies of formation and entropies of these phases, calculated their Gibbs free energies (ΔfG°) of formation and evaluated their stability with respect to Na2SO4, simple sulfates MSO4·xH2O, and liquid water, if appropriate. The ΔfG° values (all data in kJ mol−1) are: Na2Ni(SO4)2·4H2O: −3032.4 ± 1.9, Na2Mg(SO4)2·4H2O: −3432.3 ± 1.7, Na2Co(SO4)2·4H2O: −3034.4 ± 1.9, Na2Zn(SO4)2·4H2O: −3132.6 ± 1.9, Na2Mn(SO4)2·2H2O: −2727.3 ± 1.8. The data allow the stability of these phases to be assessed with respect to Na2SO4, MSO4·mH2O and H2O(l). Na2Ni(SO4)2·4H2O is stable with respect to Na2SO4, NiSO4 and H2O(l) by a significant amount of ≈50 kJ mol−1 whereas Na2Mn(SO4)2·2H2O is stable with respect to Na2SO4, MnSO4 and H2O(l) only by ≈25 kJ mol−1. The values for the other blödite–kröhnkite phases lie in between. When considering the stability with respect to higher hydrates, the stability margin decreases; for example, Na2Ni(SO4)2·4H2O is still stable with respect to Na2SO4, NiSO4·4H2O and H2O(l), but only by ≈20 kJ mol−1. Among the phases studied and chemical reactions considered, the Na–Ni phase is the most stable one, and the Na–Mn, Na–Co, and Na–Cu phases show lower stability.

Improvement of the Preparation of Ammonium Ferrous Sulfate Based on Carbon Black and a Magnet

Improvement of the Preparation of Ammonium Ferrous Sulfate Based on Carbon Black and a Magnet

An Example of Teaching Design for the First-Class Off-Line Course “Basic Chemistry Laboratory (I)” at Xiamen University: Preparation, Composition and Impurity Analysis, Application of Ammonium Ferrous Sulfate

An Example of Teaching Design for the First-Class Off-Line Course “Basic Chemistry Laboratory (I)” at Xiamen University: Preparation, Composition and Impurity Analysis, Application of Ammonium Ferrous Sulfate

Process Flowsheet Development for Separation of Sm, Co, Cu, and Fe from Magnet Scrap.

A complete process flowsheet to recover metal values from Sm2Co17-type magnet scrap was investigated. The magnet scrap was leached in chloride medium at pulp density of 2% (w/v) under the optimum conditions of 15% (v/v) HCl and 5% (v/v) H2O2 at 70 °C for 3 h, which yielded 98.5% Sm and 99% Co extractions. The full factorial Design of Experiment technique was adopted for the optimization of leaching conditions. Sm was selectively separated from the leach liquor as precipitated double salt using Na2SO4. The precipitated double sulfate was later converted to Sm-oxalate, which was subsequently calcined to produce pure Sm2O3. Following Sm separation, Fe was removed through precipitation by raising the pH to 3.0. For Cu and Co recovery, solvent extraction techniques using LIX 84I and Na-CYANEX 272, respectively, were followed. The McCabe–Thiele diagrams for extraction as well as stripping were presented for both Cu and Co.

Studies on Alum as Milk Coagulating Agent in the Manufacture of Paneer – An Indian Cottage Cheese

Alum is a white crystalline double sulphate of aluminum and potassium that is commonly used as an astringent. Utilising its protein binding property, alum was studied as coagulating agent of milk in the preparation of paneer. Paneer is a soft variety of cottage cheese very popular in Indian sub-continent, used in various culinary dishes. Its preparation essentially involves acid coagulation of hot milk and pressing of the hot coagulum to form a compact block which is then cooled by immersing in chilled water. Citric acid and vinegar are commonly used as coagulating agents of milk during paneer manufacture. However, when alum was used as a coagulating agent, it was observed that most of the proteins were amalgamated during coagulation process resulting in enhanced yield of paneer. It also resulted in reduced solids losses in whey. However, use of alum resulted in a slight astringency in paneer, hence it was recommended to be used in combination with common coagulant i.e. citric acid. The solids content (losses) in whey were 6.62, 6.08, and 6.32 %, respectively for citric acid, alum and citric acid + alum mixture used as coagulating agents. Similarly, the yields of paneer were 16.42, 19.04 and 16.99 %. The alum coagulated paneer looked glossy and attractive which was indicated by reflectance values of 83.75% as against 79% for control paneer sample. The paneer made by alum coagulation had slightly brittle texture.

Crystal and electronic structure, thermochemical and photophysical properties of europium-silver sulfate monohydrate AgEu(SO4)2·H2O

In order to synthesize single crystals of europium-silver double sulfate monohydrate, a hydrothermal reaction route was used. It was found that the crystallization cannot be performed under standard conditions. The compound AgEu(SO4)2·H2O crystallizes in the trigonal crystal system, space group P3221 (a ​= ​6.917(1), c ​= ​12.996(2) Å, V ​= ​538.53(17) Å3). The structure consists of triple-capped trigonal prisms [EuO9], in which one oxygen atom belongs to crystalline water, silver octahedra [AgO6], and sulfate tetrahedra [SO4]. The hydrogen bonds in the system additionally stabilize the structure. The electronic band structure wasstudied by density functional theory calculations which show that AgEu(SO4)2·H2O is an indirect band gap dielectric. Temperature dependent photoluminescence spectroscopy shows emission bands of transitions from the 5D0 state to the spin-orbit components of the 7FJmultiplet (J ​= ​0–6).The ultranarrow transition 5D0 - 7F0 shows a red shift with respect to other europium-containing water-free sulfates that is ascribed to the presence of OH group in the crystal structure in the close vicinity of the Eu3+ ion. An effect of abnormal sensitivity of the Ω4 intensity factor to minor distortions of the local environment is detected for the observed low local symmetry of C2.

Study on the Detection Method of Alum Content in Sweet Potato Starch by Terahertz Spectroscopy

Study on the Detection Method of Alum Content in Sweet Potato Starch by Terahertz Spectroscopy

Synthesis of iron molybdate from molybdenum spent catalyst and evaluation of its electrochemical properties

AbstractThe current manuscript deals with synthesis of iron molybdate nano‐material from molybdenum spent catalyst via roasting, leaching, and hydrothermal precipitation. Experimental parameters like ratio of spent catalyst to sodium carbonate during roasting, time duration of leaching, and concentration of ammonia to obtain molybdenum into leach solution were optimized. A maximum 93% Mo was extracted from roasted catalyst in 5 M ammonia at 80°C for 5 h leaching condition. Then from the leach liquor, iron molybdate Fe2(MoO4)3 was synthesized by hydrothermal method in different iron precursors such as ferrous ammonium sulphate, ferric nitrate, and ferric sulphate. Then, different synthesis parameters were optimized for the synthesis of Fe2(MoO4)3. Based on the optimal conditions, a tentative flow‐sheet has been proposed and factors influencing the morphology of the product have been discussed. This Fe2(MoO4)3 showed capacitive behavior confirmed through cyclic voltammetry study and a maximum specific capacitance of 33 F g−1 was estimated.

Lamellar and Supramolecular Feature of New Tutton’s Salts Incorporating 2-Amino-4-Methylpyrimidine: Thermal Stability, Optic Study, Antioxidant and Antimicrobial Activities

The slow evaporation reaction of 2-amino-4-methylpyrimidine and transition metal cation (MII = Fe and Ni) in the presence of sulfuric acid H2SO4 affords two novel double sulfate salts with similar general formula (C5H8N3)2[MII(H2O)6](SO4)2·2H2O (MII = Fe and Ni) abbreviated FePRM and NiPRM, respectively. Their structures have been determined by single-crystal X-ray diffraction analyses and further characterized by Infra-Red (IR) spectra, thermogravimetric analysis—differential scanning calorimetry (TG-DSC) and variable temperature powder X-ray diffraction (VT-PXRD) measurements. Structural characterization shows that the interplay of N–H···O, O–H···O and π···π interactions between lattice and coordinated water and ligands significantly contribute to the crystal packing leading to the formation and strengthening of three dimensional supramolecular assembly. Then, the structure exhibits lamellar topology where the interlayer distances are 13.065(4) and 13.138 (5) A for FePRM and NiPRM, respectively. Hirshfeld surface analysis employing 3D molecular surface contours and 2D fingerprint plots have been used to analyze the intermolecular interactions present in the crystals. The optical properties were characterized by UV–visible spectroscopy and the calculated band gap was estimated to be 3.91 and 4.08 eV for FePRM and NiPRM, respectively. In addition, the biological activities of the complexes were investigated through the scavenging effect on DPPH radicals, reducing and phosphonolybdonum assay as antioxidant activities.

Negative thermal expansion in one-dimension of a new double sulfate AgHo(SO4)2 with isolated SO4 tetrahedra

A double holmium-silver sulfate was obtained for the first time. The temperature intervals for the formation and stability of the compound were determined by differential scanning calorimetry. The crystal structure of AgHo(SO4)2 was determined by Rietveld method. The X-ray diffraction (XRD) analysis showed that the compound crystallizes in the monoclinic syngony, space group P21/m, with the unit cell parameters a = 4.71751 (4) Å, b = 6.84940 (6) Å and c = 9.89528 (9) Å, β = 95.1466 (4)°, V = 318.448 (5) Å3, Z = 2, RB = 1.55 %, T = 303 K. Two types of sulfate tetrahedra were found in the structure, which significantly affected the spectral properties in the infrared range. In the temperature range of 143−703 K, a negative thermal expansion along the b direction accompanied by a positive thermal expansion along the a and c directions was observed. It was established that negative thermal expansion is the result of the deformation of sulfate tetrahedra, which is affected by the movement of holmium and silver atoms. The excitation in the blue spectral range (457.9 nm) produces a luminescence in light blue (489 nm), green (545 nm) and red (654 nm) spectral ranges, and the latter two were of comparable intensity that is favorable for WLED sources. The observed luminescent band distribution is ascribed to the specific crystal field at Ho3+ ion sites rather than a variation of radiationless probability.

Properties of ceria nanoparticles with surface modified by acidic groups

The effect of the precursor and surface modification by sulfate and phosphate groups on the properties of cerium oxide was studied. The obtained materials were characterized by infrared (IR) and Raman spectroscopy, X-ray powder diffraction, scanning electron microscopy (SEM), high resolution transmission electron microscopy (TEM), thermogravimetric analysis (TGA) with the gas phase composition analysis, Brunauer–Emmett–Teller (BET) method, and impedance spectroscopy. The significant fraction of Се3+ ions at the surface of cerium oxide particles obtained from Ce(NO3)3 promotes the formation of double sodium cerium sulfate and cerium phosphate upon treatment with solutions of sodium hydrogen sulfate and sodium dihydrogen phosphate, respectively. The modification of ceria surface by sulfate groups leads to a decrease in specific surface area and water content of the obtained materials, as well as to a significant decrease in their proton conductivity. CeO2 samples prepared from cerium ammonium nitrate have a significantly smaller particle size and higher conductivity. Its value for cerium oxide modified with phosphate groups increases up to 3.5 × 10−4 S/cm at 65 °C. The effect of hydration degree as well as Ce3+ content on the cerium oxides properties is discussed.