RESUMEN
In order to find an effective, stable, environmentally compatible electrode for the elimination of organic pollutants, preparation of a novel graphite electrode (NGE) was explored using graphite, epoxy resin, curing agent and acetone as materials. Water, ethanol aqueous solution, acetone, ultrasound-acetone and electrochemical method were used to pretreat the electrode. The first three methods obtained poor effect. Ultrasound-acetone could improve the pretreatment, but satisfied results were difficult to achieve. Electrochemical method could work effectively. Electrochemical oxidation of phenol was carried out on NGE and commercial graphite electrode (CGE), respectively. UV spectroscopy was used to study evolution of phenol oxidation. The results showed that CGE resulted in accumulation of bensoquine in the electrolyte, though it was more effective than NGE on phenol oxidation. While much less benzoquinone was found in the electrolyte for NGE. TOC removal rate were 40% and 31% for NGE and CGE, respectively. SEM study showed that CGE was severely corroded after phenol degradation, while NGE was undamaged, showing good stability.
Asunto(s)
Electroquímica/instrumentación , Electrodos , Grafito , Fenol/aislamiento & purificación , Eliminación de Residuos Líquidos/métodos , Electrólitos , Diseño de Equipo , Residuos Industriales , Oxidación-Reducción , Fenol/química , Compuestos de Amonio Cuaternario/química , Compuestos de Amonio Cuaternario/aislamiento & purificación , Purificación del Agua/instrumentaciónRESUMEN
To study the chemical constituents of Fritillaria monanth Migo, the constituents were separated and purified by column chromatography on silica gel, and the structures were identified by NMR, MS spectral data. Six compounds were isolated and identified as ent-kauran-15-en-17-ol (I), entkauran-15-en-3alpha, 17-diol (II), fritillaziebinol (III), ent-kauran-16a, 17-diol (IV), ent-kauran-3alpha, 16alpha,17-triol (V), ent-16,17-epoxy-kauran-3alpha-ol (VI). All the compounds were isolated from this plant for the first time, and VI is named as ent-16,17-epoxy-kauran-3alpha-ol, which is a new compound.
Asunto(s)
Diterpenos de Tipo Kaurano/aislamiento & purificación , Fritillaria/química , Diterpenos de Tipo Kaurano/química , Estructura Molecular , Raíces de Plantas/química , Plantas Medicinales/químicaRESUMEN
Electrokinetic remediation (EK) and its combined methods are emerging technologies to remove POPs from contaminated soils in situ in last decade. This paper reviews the five major kinds of electrokinetic remediation methods for POPs from contaminated soils: (1) Classic electrokinetic method; (2) Electrokinetic-Fenton method; (3) Electrokinetic remediation combining with bioremediation method; (4) Electrokinetic remediation combining with surfactants/cosolvents method; (5) Electrokinetic remediation combining with ultrasonic method. The basic principle, characteristics, application areas and research developments of those five methods are discussed respectively. The future development direction of EK remediation for POPs from contaminated soils is anticipated.