104 research outputs found

    Preparation of a Modified PTFE Fibrous Photo-Fenton Catalyst and Its Optimization towards the Degradation of Organic Dye

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    Polytetrafluoroethylene (PTFE) fiber was grafted with acrylic acid to impart the carboxyl groups onto the fiber surface, which were used to coordinate with both transition metal ions Fe(III) and Cu(II) and a rare metal ion Ce(III) to prepare the metal grafted PTFE fiber complexes as the novel heterogeneous Fenton catalysts for the degradation of the azo dye in water under visible irradiation. Some factors affecting the preparation process, such as nature and concentration of metal ions in the coordination solution, grafting degree of PTFE and reaction temperature were optimized with respect to the content and strength of metal fixation on the fiber and dye degradation efficiency. The results indicated that increasing metal ion concentrations in solution and grafting degree of PTFE fiber as well as higher coordination temperature led to a significant increase in metal content, especially Fe(III) and Cu(II) content of the complexes. Fe(III) ions fixed on the fiber showed the better catalytic performance than Cu(II) and Ce(III) ions fixed when three different complexes with similar metal content being employed, respectively. Moreover, Increasing Fe content or incorporation of Cu(II) ions could significantly improve the catalytic activity of the complexes

    Renovation and Reuse of Reactive Dyeing Effluent by a Novel Heterogeneous Fenton System Based on Metal Modified PTFE Fibrous Catalyst/H 2

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    Cu-Fe bimetallic grafted polytetrafluoroethylene (PTFE) fiber complexes were prepared and optimized as the novel heterogeneous Fenton catalysts for the degradation of reactive dyes under UV irradiation. Cotton fabrics were dyed with three reactive dyes, namely, Reactive Red 195, Reactive Yellow 145, and Reactive Blue 222, in tap fresh water using exhaustion process. The spent dyeing effluents were then collected and degraded with the optimized Cu-Fe bimetallic grafted PTFE fiber complex/H2O2 system. The treated dyeing effluents were characterized and reused for the dyeing of cotton fabrics through the same process. The effect of reuse process number on quality of the dyed cotton fabrics was examined. The results indicated that the Cu-Fe bimetallic modified PTFE fiber complex with a Cu/Fe molar ratio of 2.87 was found to be the most effective fibrous catalyst, which enhanced complete decolorization of the treated dyeing effluents with H2O2 in 4 h. However, the TOC removal for the treated dyeing effluents was below 80%. The dyeing quality was not affected for three successive cycles. The increase in residual TOC value influences fourth dyeing cycle. Further TOC reduction of the treated effluents is needed for its repeated reuse in more than three dyeing cycles

    Preparation of a Modified PTFE Fibrous Photo-Fenton Catalyst and Its Optimization towards the Degradation of Organic Dye

    Get PDF
    Polytetrafluoroethylene (PTFE) fiber was grafted with acrylic acid to impart the carboxyl groups onto the fiber surface, which were used to coordinate with both transition metal ions Fe(III) and Cu(II) and a rare metal ion Ce(III) to prepare the metal grafted PTFE fiber complexes as the novel heterogeneous Fenton catalysts for the degradation of the azo dye in water under visible irradiation. Some factors affecting the preparation process, such as nature and concentration of metal ions in the coordination solution, grafting degree of PTFE and reaction temperature were optimized with respect to the content and strength of metal fixation on the fiber and dye degradation efficiency. The results indicated that increasing metal ion concentrations in solution and grafting degree of PTFE fiber as well as higher coordination temperature led to a significant increase in metal content, especially Fe(III) and Cu(II) content of the complexes. Fe(III) ions fixed on the fiber showed the better catalytic performance than Cu(II) and Ce(III) ions fixed when three different complexes with similar metal content being employed, respectively. Moreover, Increasing Fe content or incorporation of Cu(II) ions could significantly improve the catalytic activity of the complexes

    Super-heated Steam Drying: an Innovation of Clean Coal Technology for Lignite

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    A comprehensive overview of the status of lignite pre-drying technology is given in this study. The practical problems of high energy consumption, high investment and poor safety exist in the lignite drying using the traditional thermal drying, for the reason that the super-heated steam drying technology for lignite is put forward. The mechanism experiment research and pilot-scale test research of the super-heated steam drying technology for lignite were carried out, and the results show that the drying efficiency of the super-heated steam is better than the hot air at given conditions, the lignite drying can be accomplished stably and continuously and the drying product can meet the requirement of the industrial application of the lignite fired power plant. A more innovative approach as a new lignite Super-heated steam low-rank Coal Upgrading (SCU) is proposed by Energy Conservation Research Center of Shandong Academy of Sciences. The technical advancement in terms of energy-saving and safety among the applied technologies are compared and analyzed, and the results show this technology has the advantages of low energy consumption, high safety and energy saving. To sum up, the exploitation of the super-heated steam drying technology for lignite fired power plant can promote the development of the energy and power industry, and the technology has wide application prospect

    Molecular Analysis of Evolution and Origins of Cultivated Hawthorn (Crataegus spp.) and Related Species in China

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    Hawthorn is of high economic value owing to its medicinal properties and health benefits. Crataegus is a member of the Rosaceae family; the genus has a complicated taxonomic history, and several theories on its origin have been proposed. In this study, 53 accessions from seven Crataegus taxa native to China and accessions of exotic Crataegus species (two from Europe and one from North America) were analyzed by specific locus amplified fragment sequencing (SLAF-seq). In total, 933,450 single-nucleotide polymorphisms were identified after filtering and used to investigate the species’ genomic evolution. Phylogenetic trees derived from nuclear simple sequence repeats (SSRs) and SLAF-seq data showed the same topology, in which Crataegus maximowiczii and Crataegus sanguineae formed a closely related cluster that was clearly separated from the cluster composed of Crataegus hupehensis, Crataegus pinnatifida, Crataegus pinnatifida var. major, Crataegus bretschneideri and Crataegus scabrifolia. Phylogenetic and structure analysis indicated that the seven Chinese Crataegus taxa had two separate speciation events. Plants that evolved the southwestern route shared the genepool with the European species, whereas plants along the northeastern route shared the genepool with the North American species. TreeMix genetic analysis revealed that C. bretschneideri may have a hybrid origin. This study provides valuable information on the origins of Chinese Crataegus and suggests an evolutionary model for the main Crataegus species that native to China

    Preparing Multi-Functional Protein Textiles by the Flavonoid-Rich Ginkgo Biloba L. Leaf Extracts

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    ABSTRACTFlavonoids in ginkgo biloba L. leaf (abbreviated as GBL) extracts exhibited superior biological activity, but their light color limited their development in the field of textiles. Therefore, this work innovatively used GBL extracts as textile functional finishing agent, through exhaustion dyeing process endowed protein fabrics the multifunction. Flavonoids of GBL in protein fabrics showed outstanding rubbing and washing fastness, becuase of their formed strong affinity by electrostatic attraction, hydrogen bond and van der Waals force. Moreover, the flavonoid content on protein fibers was enhanced by the GBL extract concentration increase, treating time stretch, temperature improve. Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy result that flavonoids in GBL extracts adsorbent the fibers. In addition, the treated protein fabrics possessed good antioxidant, antibacterial and heavy metal protective performance. Finally,GBL dyed silk fabrics exhibited stronger functionalities than GBL dyed wool fabrics. This work provides the methods that reuse GBL waste and functionalization of protein fabric
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