Synthesis and Evaluation of 8-Aminoquinoline-Grafted Poly(glycidyl methacrylate) for the Recovery of Pd(II) from Highly Acidic Aqueous Solutions

A new adsorbent was prepared via modified poly(glycidyl methacrylate) with 8-aminoquinoline (AQ-PGMA) for the recovery of Pd(II) from solution. The practical application values of AQ-PGMA, including efficiency, selectivity and reusability for the recovery of Pd(II), are proved by the various experiment parameters. The parameters include HCl concentration, adsorption time, initial Pd(II) concentration, coexisting ions and reused cycles. The prepared AQ-PGMA showed a high adsorbing capacity for Pd(II) (up to 267.90 mg/g) when the concentration of HCl is higher than 0.4 mol/L. The analysis of the adsorption process indicated that the adsorption kinetics followed a pseudo-second-order kinetic model and the adsorption isotherms obeyed the Hill model. The Hill model showed that one adsorption site on the AQ-PGMA could combine 1.45 Pd(II). In addition, the obtained adsorbent demonstrated good regenerative ability and satisfying selectivity for the recovery of Pd(II). The adsorption mechanism was dominated by the chelation and ion exchange reactions between amines/hydroxyl groups and Pd(II). The experiments confirmed that AQ-PGMA was efficient for recovery of Pd(II) from highly acidic aqueous solutions

Aeronautics design and manufacture integrated enterprise model

In order to realize the integration and concurrent of design and manufacture, enhance the efficiency of aircraft development enterprises, a model centre based design and manufacturing integrated enterprise model is proposed. The model centre consists of central system models, product models and process model. The design and manufacture integrated development model based on the unified model centre is discussed. Finally, a maturity control method supporting design and manufacturing integration is proposed

Selective Adsorption of Ag+ on a New Cyanuric-Thiosemicarbazide Chelating Resin with High Capacity from Acid Solutions

A new cyanuric-thiosemicarbazid (TSC-CC) chelating resin was synthesized and employed to selectively adsorb Ag+ from acid solutions. The effects of acid concentration, initial concentration of Ag+, contact time and coexisting ions were investigated. The optimal acid concentration was 0.5 mol/L. The adsorption capacity of Ag+ reached 872.63 mg/g at acid concentration of 0.5 mol/L. The adsorption isotherm was fitted well with the Langmuir isotherm model and the kinetic data preferably followed the pseudo-second order model. The chelating resin showed a good selectivity for the Ag+ adsorption from acid solutions. Fourier transform infrared (FT-IR), X-ray diffraction (XRD), Scanning electron microscopy/energy dispersive spectrometer (SEM-EDS) and X-ray photoelectron spectroscopy (XPS) were used to study the adsorption mechanism. The chelating and ionic interaction was mainly adsorption mechanism. The adsorbent presents a great potential in selective recovery Ag+ from acid solutions due to the advantage of high adsorption capacity and adapting strongly acidic condition. The recyclability indicated that the (TSC-CC) resin had a good stability and can be recycled as a promising agent for removal of Ag+

Enhancement of copper metal dissolution in sulfuric acid solution with oxygen and ultrasound

A new method for copper metal dissolution by simultaneous use of oxygen and ultrasound was proposed to enhance the copper dissolution rate in sulfuric acid (H2SO4). The influence factors such as ultrasonic power, oxygen flow rate, reaction temperature, initial copper ion (Cu2+) and H2SO4 concentration was studied to study the dissolution behaviour of copper metal. The dissolution rate of Cu could reach 7.52 g h−1 L−1 after the ultrasonic strengthening, which is 1.83 times higher than that without ultrasonic irradiation (4.109 g h−1 L−1). The study of leaching kinetics found that the Cu leaching process with and without ultrasound were both controlled by surface chemical reaction. The ultrasound could significantly reduce the apparent activation energy of the leaching reaction from 43.52 kJ mol−1 to 28.40 kJ mol−1. Characteristics revealed that the cavitation effect of ultrasound could increase the specific surface area of copper metal and oxygen bubble, and enhance the oxidizing capability of this leaching system, which is beneficial for the dissolution of Cu. Therefore, ultrasonic-assisted technology has provided novel insights for the hydrometallurgical recovery of copper

Calculation method of spherically expanding flame propagation radius to consider ignition electrode effects

Abstract Ignition electrodes have an immense impact on the accurate measurement of the flame propagation spherical radius. In this study, a flame-radius calculation method is designed. The method is able to eliminate effects due to the ignition electrodes. The adaptability and optimization effects of the proposed method are analyzed. The results show that the ratio of the angle is affected by the ignition electrodes under the Han II method. There are three obvious divisions include a high-value area, a sharp-variation area, and a mild-variation area. The ratio of the angle affected by the ignition electrodes is only applicable to the mild-variation region when the flame presents respective convex and concave distributions. For these distributions, the increment rate of the mean radius is 0.4–0.85% and 0.42–3.19%. The reduced rate of the standard deviation of the radius extraction value is 11.91–22.1% and 5.13–17.99%, and the reduced rate of the radius extraction value range is 20.32–39.51% and 0.32–8.09%