Papers by Keyword: Purification

Abstract: The purification of mixed hydroxide precipitate leaching solution from impurities was conducted via solvent extraction using the commercial extractant di(2-ethylhexyl) phosphoric acid (P₂₀₄ or D2EHPA). The impurities that were removed are Mn²⁺, Cu²⁺, Ca²⁺, Mg²⁺, and Zn²⁺, while the desired metals remained in aqueous phase which are Co²⁺ and Ni²⁺. Solvent extractions were studied on a batch scale to improve the effect of organic-to-aqueous phase ratio, extractant concentration, saponification rate, and feed solution pH to the removal of impurities. High selectivity of impurities was obtained at a phase ratio organic to aqueous of 1.6:1, extractant concentration of 30 vol%, with saponification rate of 40%, and feed solution pH of 5. The extraction rate achieved for Mn²⁺, Cu²⁺, Ca²⁺, Mg²⁺, and Zn²⁺ are 88.46%, 82.24%, 95.21%, 38.10%, and 99.99% respectively while the co-extracted of Co²⁺ and Ni²⁺ are 17.76%, and 12.52%.

Abstract: Cassava peels (CP) are agricultural-industrial co-products, better means of generating wealth that have recently attracted the attention and efforts of scientists due to their vitality in achieving a higher standard of living in a variety of industrial applications and human health care. Hence, an urgent demand for low-cost, non-toxic nanostructure material that can host, deliver, and transmit light with improved optical properties. In this work, β-cyclodextrins (β-CDs) was produced from cassava starch using US132 Cyclodextrins glucanotransferase enzyme (CGTase), converting it to cyclic oligosaccharides using experimental designs. The β-CDs produced by US132 CGTase are subsequently refined to a high level (67.26 g L-1) and homogenized using an eco-friendly, straightforward crystallization process that yielded a 40% purification yield. Gold nanoparticles (AuNPs) was effectively synthesized from Kahaya senegalenses plant, as a natural reducing agent. The Uv-visible and SEM evaluations revealed the plasmon resonance bands and spherical cap-shaped morphology of the developed hybridized β-CDs/AuNPs. However, the functional groups contained in the developed nanohybrids were validated by the FT-IR analysis. The size and crystallinity of the developed sample was found within the nano range as deduced from XRD and TEM (20-20 nm) analysis. The successful formation the developed nanostructured β-CDs/AuNPs was confirmed employing Uv-Visible, XRD, FT-R and SEM analysis. Therefore, the developed nanostructured β-CDs/AuNPs displayed significant and noticeable advantages which can withstand present drifts, due to its environmental friendliness, biocompatibility and encapsulating effect.

Abstract: This study aims to synthesize, purify, and modify magnetic carbon nanofibers (Mag-CNF) into hydrophilic carbon material. The synthesis method was carried out by chemical vapor deposition (CVD) using the catalyst from Incolloy at 800°C with argon, nitrogen, hydrogen, and acetylene gases. The purification of Mag-CNF was then conducted by dissolving Mag-CNF with toluene and ethanol, followed by vacuum annealing. The hydrophilization of Mag-CNF was further performed by adding amine groups via reacting Mag-CNF with ethylene diamine, NaNO₂, and H₂SO₄. The successfully prepared Mag-CNF has characteristics of tubular tube bundles consisting of carbon nanofibers with an average diameter of 100-120 nm. The X-ray diffraction (XRD) profile shows the characteristics of carbon, iron, iron oxide, and iron carbide. The Raman spectra show the existence of D, G, and G' bands corresponding to the characteristics of carbon nanomaterials. The magnetic property characterization using a vibration sample magnetometer (VSM) shows the synthesized product as ferrimagnetic materials. The modification results show the addition of hydrophilic groups to Mag-CNF, such as O–H and N–H groups, as analyzed in Fourier Transform Infrared (FTIR) spectra. The successful hydrophilization was also visually confirmed using a dispersion test in water, showing that Mag-CNF has better dispersion after surface modification.

Abstract: The article shows the process of preparing an oxide layer on the surface of titanium for use in industrial catalysis. Data from physical and chemical studies are presented, namely microhardness, porosity, thickness, specific surface area, adhesion and thermal stability of the active layer.To determine the physicochemical characteristics of the resulting oxide layer, the following analysis methods were used: X-ray diffraction analysis (XRD), X-ray diffraction phase analysis (XPA), X-ray absorption analysis (XRA), and X-ray fluorescence analysis. The thickness of the oxide layer depending on the duration of anodization was estimated by optical microscopy.

Abstract: Purification of heavy metal ions from wastewater is of prime importance for a clean environment and human health. Different reported methods were devoted to heavy metal ions removal from various wastewater sources. These methods could be classified into adsorption-, membrane-, chemical-, electric-, and photocatalytic-based treatments. This article reviews and discusses these methods in terms of used agents/adsorbents, removal efficiency, operating conditions, and the pros and cons of each method. Generally, it was noticed that most of the recent studies have focused on adsorption techniques. Even though the chemical and membrane methods are practical, the large-volume sludge formation and post-treatment requirements are vital issues that need to be solved for chemical techniques. Fouling and scaling inhibition could lead to further improvement in membrane separation.

Abstract: The future applications of amylase have sparked the interest of several industries, resulting in the discovery of possible amylase-producing microbes. Aspergillus niger ICP2 was an indigenous fungus isolated from coffee pulp that shows amylolytic activity after growing on a soluble starch agar. In this study, we optimized the production and successfully purified the amylase from Aspergillus niger ICP2. Amylase optimization production was performed for a 7-day of incubation under submerged fermentation. The amylase activity was measured using the iodin method, and the total protein was quantified spectrophotometrically at 280 nm. Purifying amylase crude extract conducted such as ammonium sulfate precipitation, dialysis, and anion-exchange chromatography. Amylase was maximally precipitated at 90% saturation, followed by dialysis on a 10 kDa column, increasing specific activity up to 12.17 U/mg and purity multiples of 9.31 times. Two peaks of amylase activity were formed when the dialyzed amylase was loaded onto anion exchange chromatography with specific activities of 14.47 U/mg (fraction I) and 32.73 U/mg (fraction II). The increase in specific activity and purity fold indicated that the amylase purification process was successful.

Abstract: Kratom (Mitragyna speciosa Korth) leaves contain a major alkaloid, mitragynine, which has opioid pain-relieving activity. Kratom and its derivatives are abused as alternatives to other narcotics. Therefore, this preliminary study was aimed to optimize the extraction of mitragynine from kratom investigating the effect of extraction time and ultrasonication on yield and quality of extract (the content of mitragynine). The extraction was carried out sequential extraction at room temperature and treatment of ultrasonication before extraction which was followed the purification process. Ultrasound-assisted extraction increased mitragynine yield to16.88%, compared to extraction without ultrasonication. The extract was purified by column chromatography, eluted with a mixture of n-hexane - ethyl acetate - 25% ammonia with a ratio of 30:15:1 (v/v). Likewise, the highest mitragynine purity obtained was 86.46%.

Abstract: Graphite is a strategically scarce resource, and the preparation of high-purity graphite is the prerequisite and basis for the application of graphite. In order to determine the optimal purification technology parameters of an ultra-large flake graphite mine pneumatic separation ore with a fixed carbon content of 77.69%, a particle size of mainly 10 to 40 mesh, and main impurities of calcium carbonate, iron oxide and silica , two additional experiments of acid method and alkali method were added on the basis of alkali-acid method, to investigate the purification effect of different technological processes and acid leaching times on graphite raw materials, as well as to analyze the retention extent of different methods and alkali fusion temperature on graphite ultra-large flake structure. The results show that all three methods can increase the fixed carbon content of graphite to above 99%. However, compared with the acid method and the alkali method, the alkali-acid method can obtain high-purity graphite while also better protecting the graphite's ultra-large flake structure. The optimal fusion temperature is 400 °C, the optimal acid leaching time is 30% sulfuric acid thrice and 5% hydrofluoric acid once. After purification, the fixed carbon content of the product exceeds 99.97%.

Abstract: Purification on kappa (ƙ) carrageenan was performed by dissolving ƙ-carrageenan powder in distilled water and re-precipitated with ethanol and n-hexane separately during re-precipitation process. The purified kappa carrageenan was analyzed by using Fourier transform infrared (FTIR) spectroscopy and carbon, hydrogen, nitrogen, and sulfur (CHNS) elemental analysis. The outcomes from FTIR showed there are physical changes due to intermolecular interactions which lead to decrease and lower intensity of hydroxyl band at 3345 cm^-1 after re-precipitated with n-hexane, compared to re-precipitation with ethanol and unpurified ƙ-carrageenan. There were variations observed in the percentages of C, H and S in the CHNS analysis between unpurified and purified ƙ-carrageenan. The successfully purified ƙ-carrageenan are suitable to be used for further application.

Abstract: A novel, highly active and effective adsorbent has been developed using solid state mixing method of natural bentonite and CaO. The so called CaO/bentonite nanocomposite was determined the optimum heating temperature and bentonite-to-CaO ratio to enhance the quality of patchouli oil by purification process technology. The adsorbents were characterized by XRD, FTIR, SEM, GSA and TG/DTA. The total acid value of patchouli oil was determined by using KOH. The test method to determine physical and chemical properties of patchouli oil in Indonesia has been set nationally through SNI 06-2385-2006. A significant decrease in acid value of patchouli oil (from 5.42 to 0.34 mg KOH/g oil) was observed after purification of patchouli oil over CaO/bentonite-300 (20:80) nanocomposite. After patchouli oil purification over CaO/bentonite-300 (20:80), the concentration of patchouli alcohol (PA) was increased from 33.08 to 34.82%, while Fe content was decreased from 4.25 to 1.56 ppm.