Diagnosis Of Active Ingredient And Application Of Glow-Discharge Electrolysis Plasma

This paper is introduced the basic theory and the application of the glow discharge electrolysis plasma(GDEP) technology. Then, we measured the concentration of heavy metal ions in the solution and synthetised hydrogels used glow-discharge electrolysis. The swelling and dye adsorption of the hydrogel were investigated to lay a theoretical foundation for agriculture and horticulture, wastewater treatment and biomedical. This thesis is divided into five chapters:Chapter 1: The classification and generation method of plasma, concept, development and application of glow-discharge electrolysis plasma, preparation method and properties of the hydrogel, innovation and deficiency of this thesis were mainly introduced.Chapter 2: The spectrum diagnosis of the glow-discharge electrolysis plasma were mainly made analysis. the various free radicals produced discharge in sodium sulfate solution and the effects of discharge voltage no emission intensity of radicals were investigated. The discharge electron temperature and density in different medium trend along with the change of voltage were also studied. The results show that the glow-discharge electrolysis can produce large amounts of HO˙, O˙, H˙ and so on. The free radical emission spectrum intensity is enhanced by the increase of voltage. We also found that in salt solution, the electron temperature discreases with voltage rising. However, in the acid solution, the electron temperature increases with the voltage rising. Regardless of the salt solution or the acid solution, the electron density discreases with voltage rising.Chapte 3: A new reactor termed as glow-discharge electrolysis(GDEP) was modified and designed according to the principle and characteristic of electrolyte cathode glow-discharge(ELCAD) for the determination of cadmium in aqueous solution. The effects of discharge voltage and solution concentration on the discharge stability, signal strength, sensitivity and detection limit were examined in detail. The results showed that with the increasing of discharge voltage from 600 V to 720 V, the electronic temperatures were increased from 2000 K to 3300 K, electron densities were decreased from 2.47×1016 cm-3 to 1.77×1016 cm-3, emission intensities were enhanced and the limits of detection for cadmium were ranged from 2.95 mg/L to 1.22 mg/L. All results demonstrated that the GDEP-AES is a promising technique in detection of metal elements in aqueous soltion because of small size of discharge equipment, low energy consumption, high discharge stability, small background spectrum interference and high sensitivity.Chapter 4: A palygorskite/poly(ethylene glycol)/acrylic acid(PGS/PEG/AA) hydrogel was prepared in aqueous solution by GDEP induced graft copolymerization, in which N,N’-methylenebisacrylamide(MBA) was used as a crosslinker. The structure and morphology of the hydrogel were characterized by FT-IR, XRD and SEM. The adsorption behavior of hydrogel for cationic dyes was investigated. Factors influencing the adsorption of cationic dyes such as solution pH, contact time were investigated by batch experiments. The results showed that PEG and AA had successfully grafted to the PGS. The hydrogel possessed a better interface compatibility and exhibited undulant, rough and porous surface. The best parameters for the removal of dyes were p H 6.2 and the equilibrium contact time 3 h. The adsorption process can be well described by the pseudo-second-order kinetic. The adsorption capacities of PGS/PEG/AA hydrogel for MG, MB, RB, and CV were 507.2, 1 798.3, 311.2, 1 184.6 mg/g, respectively. The adsorption mechanism was also discussed.Chapter 5: A palygorskite/poly(2-acrylamido-2-methyl-1-propanesulfonic acidco-acrylamide)(PGS/P(AMPS-co-AM)) superabsorbent hydrogel was prepared in aqueous solution using GDEP initiated graft copolymerization, in which N,N’-methylene bisacrylamide was used as a crosslinking agent. A initiated copolymerization mechanism by GDEP was proposed. The structure, thermal stability and morphology of PGS/P(AMPS-co-AM) were characterized by FT-IR, XRD, TG and SEM. The swelling kinetics, and influence of various pH and salt solutions on the equilibrium swelling were investigated. In addition, the pH-reversibility behaviors were preliminarily investigated with alternating pH between 6.5 and 2.0. Adsorption kinetics of cationic dyes were studied using commonly kinetic models. The results indicated that the maximum equilibrium swelling of hydrogel in distilled water is 654 g/g. The equilibrium swelling of the hydrogel in salt solutions from highest to lowest is Na+> Mg2+> Fe3+. The hydrogel is responsive to the pH. The adsorption process of dyes follows the pseudo-second-order kinetic model.