A New Purification Process of Solanesol Based on Chemically Modified Diatomite

Diatomite is a kind of natural material with adsorption capacity and it’s widely used in industry. The main purpose of this paper is to study the influence of hydrochloric acid concentration and modification time on the modification effect of diatomite. This article describes a modified method of diatomite, which can not only reduce the purification cost, but also improve the separation efficiency of solanesol. The results show that when the concentration of hydrochloric acid is 3mol/L and the treatment time is 50 minutes, the modification effect of diatomite is the best. The determination of the optimum technological conditions is conducive to the separation and purification of Solanesol by diatomite, and lays a foundation for the further development and utilization of diatomite.

Liquid-liquid extraction of Pt(IV) from hydrochloric acid solutions using PPG 425 – NaCl – H2O system

Today, metal extraction from e-waste is beneficial from both an environmental and economic point of view. Natural resources of metals, especially platinum group metals, are limited. At the same time, the amount of waste containing many valuable elements continues to grow. In this work, we studied the extraction of Pt (IV) from hydrochloric acid solutions using polypropylene glycol 425 (PPG 425). In the course of the experimental work, the dependence of the platinum extraction degree on the influence of hydrochloric acid concentration and medium pH in the polypropylene glycol 425 - sodium chloride - water system have been established. The maximum recovery (distribution coefficient > 3,5) has been achieved in the presence of 2 M HCl in an aqueous two-phase system (ATPS), which allows the use of the proposed system for the extraction of platinum from leaching solutions.

Extraction and Back-Extraction Behaviors of La(III), Ce(III), Pr(III), and Nd(III) Single Rare Earth and Mixed Rare Earth by TODGA

N,N,N′,N′-Tetraoctyl diglycolamide (TODGA), as a new extraction agent, is effective for its excellent performance and low environmental hazard, and it is very welcome for the rare earth separation process. In this paper, by controlling the extraction time, diluent type, acid type and its concentration, rare earth concentration, etc., the optimum extraction and back-extraction effects of TODGA on La(III), Ce(III), Pr(III), and Nd(III) and mixed rare earths were obtained. The experiment showed that 0.10 mol·L−1 TODGA had the best extraction effect on single rare earth under the conditions of using petroleum ether as diluent, 5 mol·L−1 nitric acid, 20 min extraction time, and 0.01 mol·L−1 rare earth. In the mixed rare earth extraction, the percentage concentrations of La(III), Ce(III), Pr(III), and Nd(III) could be achieved from 21.7%, 19.9%, 30.8%, and 22.2% at the initial stage to 90.5%, 37%, 51%, and 62% after extraction, respectively, by controlling the number of back-extraction cycles and the concentrations of hydrochloric acid and nitric acid in the back-extraction system. The TODGA–rare earth carrier system showed the best back-extraction effect when the hydrochloric acid concentration was 1 mol·L−1 and the back-extraction time was 20 min. At the same time, the mixed rare earth liquid system with low initial concentration was selected for extraction and separation of mixed rare earth. The separation effect was better, and the recovery rate was higher than that of mixed rare earth liquid system with a high initial concentration.

Preparation of Hydroxytyrosol by Acid Hydrolysis from Olive Leaves

Hydroxytyrosol (HT) is the main bioactive compound in olive leaves. However, olive leaves contain a lower level of HT and the extraction process of HT was rarely optimized. In this study, compared with two extraction methods, ultrasound was found to have a positive effect on improving the yield of HT. Therefore, ultrasound was used to assist hydrolysis of hydrochloric acid to extract HT from olive leaves. Response surface method and macroporous resins were applied to optimize the extraction process as well as enrichment of HT. The results showed that ultrasonic extraction time had a significant effect on the yield and the optimal extraction conditions were obtained: ultrasonic time was 120 min, hydrochloric acid concentration was 1.60 mol/L and the liquid-to-material ratio was 60.00 mL/g. Under the optimal extraction condition, the yield of HT was 14.11 ± 0.12 mg/g. NKA-Ⅱ macroporous resin was proved to be a suitable resin to enrich HT from extraction solution. The optimal condition for enriching HY was 250 mL of loading solution at the flow rate of 1.5 mL/min with 40 mL volume of 75% ethanol–eluent at a flow rate of 1.0 mL/min. The concentration of HT changed from 2.27% to 9.25% after enrichment by macroporous resin.

Decomposition of polyhalite with hydrochloric acid

Due to the fact that polyhalite ores are poorly soluble in water, it was of interest to study the method of their processing using acids. The influence of polyhalite size, the hydrochloric acid concentration and consumption, the ratio of L: S, the temperature and time of mixing the pulp on the useful components extraction into the solution have been studied. The optimal conditions for the decomposition of polyhalite with hydrochloric acid have been determined. The degree of useful components extraction into the solution depends on the concentration of hydrochloric acid or on the L:S ratio of the pulp, but in all cases the decomposition of polyhalite occurs without secondary crystal formation, as evidenced by the same degree of potassium and magnesium ions extraction. The degree of potassium and magnesium ions extraction from polyhalite into solution increases with decomposition process temperature, an increase in the consumption of acid and the duration of the reagents interaction, and decreases with increasing acid concentration. The CaSO4 content in the solution increases sharply with an increase in the HCl concentration and is practically independent of the process temperature. Hydrochloric acid extract can be used for phosphate raw decomposition in order to obtain complex fertilizers.

A Simple and Rapid Spectrophotometric Method for Nitrite Detection in Small Sample Volumes

A simple, rapid, and environmentally-friendly spectrophotometric method for nitrite detection was developed. Detection was based on a redox reaction with iodide ions in an acidic condition. The reaction was evaluated by detecting the increase in absorbance of the colored product of iodine at 362 nm wavelength. To obtain a good spectrophotometric performance, the iodide ions concentration, hydrochloric acid concentration, and reaction time were optimized. In the optimal condition, the developed spectrophotometric method provided a linear range of 0.0625 to 4.00 mg L−1 (r = 0.9985), reaction time for 10 min, a limit of detection of 25 µg L−1, and a limit of quantitation of 85 µg L−1. This method showed good repeatability (RSD < 9.21%), high sample throughput (9 samples min−1), and good accuracy (recovery = 88 ± 2 to 99.5 ± 0.4%). The method has the potential to be used in crime scene investigations as a rapid screening test for gunshot residue detection via nitrite detection.

Influence of Acidic Substances on Compression Deformation Characteristics of Loess

Current research theories on acid-contaminated soils indicate that acids can alter the physical properties of soils, which in turn can affect their engineering mechanical properties. However, compressibility, one of the most important mechanical properties of loess, may be affected by acidic substances. To investigate the influence of acid on the compression properties of loess, this study uses a uniaxial compressor to investigate the changes of compression properties of loess under different acid concentrations and different acid immersion times and attempts to predict the causes of macroscopic compressibility changes from the microscopic pore changes of acid-etched loess. The test results show that when the soaking time is the same, the hydrochloric acid concentration increases from 0 to 3.0 mol/L, the compression coefficient Cc increases by 43.20–87.5%, and the compression yield stress σpc decreases by 51.36–60.86%; when the concentration of hydrochloric acid is the same, the soaking time increases from 1 day to 12 days, the compression coefficient Cc increases by 119.05–197.46%, and compressive yield stress σpc decreases by 10.67–22.02%. The microscopic images of loess soaked for 12 days at 3.0 mol/L hydrochloric acid concentration were compared with those of the original loess. The percentages of micropore, small pore, mesopore, and macropore areas of original loess were 20.90%, 79.10%, 0%, and 0%, respectively. The percentages of micropore, small pore, mesopore, and macropore areas of acid-etched loess were 6.24%, 37.21%, 1.14%, and 55.40%, respectively. The enhancement of the compressive properties of acid-etched loess is the result of the coupling of acid concentration and soaking time, and the change of macroscopic compressive properties may be related to the increase of microscopic macropore area after acid erosion. The results of this study can be used as a reference for the study of soil mechanical properties in acid-contaminated soils.

Preparation of microcrystalline cellulose from Rabdosia rubescens and study on its membrane properties

Microcrystalline cellulose (MCC) from Rabdosia rubescens was prepared by acid hydrolysis, and the corresponding yield of MCC was about 94% when the hydrochloric acid concentration was 10%, the acid hydrolysis time was 70min and the acid hydrolysis temperature was 70℃. The MCC was dissolved in N-methylmorpholine-N-oxide(NMMO)by phase transformation method to prepare MCC membrane. The structure and mechanical properties of MCC membrane were studied systemically. The results showed that the cellulose structure changed from type I to type II in the process of membrane formation, and the thermal stability also decreased. The content of MCC in the casting solution has a great influence on the mechanical properties of the membranes. The higher the content of MCC, the better the comprehensive mechanical properties of the membranes. When the MCC content is 9%, the tensile strength is 8.38 MPa and the elongation at break is 26.72%. Finally, the separation properties of membrane studed by separation bovine serum albumin (BSA) from water. The results showed that the rejection rate and water flux changed positively and negatively with the change of MCC content. When the content was 5%, MCC membrane showed the best comprehensive performance, its rejection of BSA was 37.23 g/(m2·h), and the corresponding rejection rate and water flux were 88.87% and 41.89 L/(m2·h) respectively.

Study on the Manufacture and Feature of the Crushed Product of Acidic Treated Soybean Residue

Because soybean residue contains a large amount of carbohydrate, protein, fiber, fat and so on, people's interest on soybean residue is increasing day by day, in order to use soybean residue in various food industry research is carried out widely. In this, through the method of extracting water-soluble soybean polysaccharides in the soybean residue that it is rich and the method of destroying the structure of SR, the conditions of improving the physical properties of SR is determined and the research for testing its properties is done. Firstly, the method and experiment design for extract water-soluble soybean polysaccharides is determined scientifically. Secondly, in order to improve the physical properties of SR, the optimal method of solution and treatment to destroying the structure of SR is selected scientifically. Through various experiment is carried out, that the best solution to destroying the structure of SR is the diluted solution of HCl is determined scientifically. The optimal treatment condition to improve the physical properties of SR is 0.04M of hydrochloric acid concentration, 70? of temperature and 3 hours of time. The SR treated in this condition showed good powdering and the crushed products were very high in dispersion, emulsification stability and oil absorbed force.

Effect of the hydrochloric acid concentration on the surface-active and functional characteristics of linear alkylbenzenesulfonic acid

The surface-active (surface tension, adsorption, molecule cross-sectional area in the adsorption monomolecular layer) and colloidal (viscosity, critical micelle concentration, solubilization) properties in aqueous and hydrochloric acid solutions of anionic surfactant alkylbenzenesulfonic acid (ABSA) were studied. Surface activity of ABSA increases in the presence of hydrochloric acid. Two inflections were established on adsorption isotherms with inorganic acid content of 5 and 10 wt. %, which are indicative of stepwise micelle formation. The ABSA dissociation is suppressed in the presence of hydrochloric acid, and therefore it behaves as a nonionic surfactant, forming micelles at lower concentrations. Mixed micelles, formed by dissociated and non-dissociated surfactant particles, are organized with an increase of ABSA content in mixture. The value of the surfactant limiting adsorption increases significantly at small hydrochloric acid amounts in comparison with an aqueous solution. The formed monomolecular layer is denser in the presence of inorganic acid than in an aqueous solution. The solubilization of Sudan I dye in alkylbenzenesulfonic acid increases with increasing in solution acidity. The extremum points on isotherms of solubilizing ability with 5 and 10 wt. % HCl content are observed at surfactant concentrations corresponding to the beginning and end of the formation of micelles containing alkylbenzenesulfonate ion.