Preparation and surface properties of cashmere guard hair powders

TiO2 modified orthocortical and paracortical cells having enhanced photocatalytic degradation and photoreduction properties

In this study, cortical cells resultant from wool fibers were loaded with TiO₂ nanoparticles in a hydrothermal process and were then engineered as organic-nonorganic hybrid composite photocatalysts for both photodegradation of organic dyes and photoreduction of heavy metal ions. The microstructure and photocatalytic properties of TiO₂ modified cortical cells (i.e. both orthocortical and paracortical cells) were systematically characterized using a series of analytical techniques including FESEM, TEM, element analysis, Mott-Schottky curve, BET specific surface area, Zeta potentials, as well as XRD, FTIR, XPS, DRS, PL, UPS, EDS and ESR spectra. Their photocatalytic performance and trapping experiments of the TiO₂ modified cortical cells were measured in the photodegradation of methylene blue (MB) dye and Congo Red (CR) dye as well as the photoreduction of Cr(VI) ions under visible light irradiation. It was found that anatase TiO₂ nanoparticles were chemically grafted on the surface of the two cortical cells via O-Ti⁴⁺/O-Ti³⁺ bonds, and that TiO₂ nanoparticles were formed inside the orthocortical cells in the hydrothermal process. The TiO₂ modified orthocortical and paracortical cells possessed much higher photocatalytic efficiency than the commercially available TiO₂ nanoparticle powder, Degussa P25, in the photodegradation of cationic MB dye and photoreduction of Cr(VI) ions, while their photocatalytic efficiency in the photodegradation of anionic CR dye is smaller because of their greater negative Zeta potentials and photogenerated holes as the main reactive radical species. In comparison with the TiO₂ modified paracortical cells, the higher photocatalytic efficiency of the TiO₂ modified orthocortical cells was demonstrated in the photodegradation of MB dye solution and this might be due to both the S-doped TiO₂ nanoparticles infiltrated into the naturally hydrophilic orthocortical cells and the primary reactive radical species of photogenerated holes being trapped in the cells.

Research of combined adsorption-coagulation process in treating petroleum refinery effluent

The petroleum refinery industry generates a significant amount of wastewater that contains a high level of organic matter, which calls for effective and costly treatments. In this research, the effectiveness of the petroleum refinery effluent (PRE) treatment with physicochemical process of combined adsorption and coagulation was evaluated. The effects of initial pH, hydraulic condition , and combined sequence of treatment process, different treating reagent types and dosages on the chemical oxygen demand (COD) removal were investigated. Additionally, the elimination efficiency of pollutant wastewater was monitored by gas chromatography-mass spectrometry (GC-MS), and Fourier transformed infrared (FT-IR) spectrophotometer was adopted to describe the structure of the wastewater. Wooden activated carbon was chosen as adsorbent at the dosage of 10 g/L as a primary treatment, and 1500 mg/L polymeric magnesium ferric sulfate was used in coagulation. Results showed that adsorption and subsequent coagulation displayed the best performance when initial pH was 9 at shear rates (G) of G1 = 65 s^-1 and G2 = 20 s^-1, which reached maximal removal rate of COD and total organic carbon GC-MS testing result revealed that adsorption was effective in phenols and iso-alkanes removal, whereas coagulation was good at removing esters and n-alkanes.

Species-specific PCR for the identification of goat cashmere and sheep wool

In order to establish rapid and species-specific method of goat cashmere and sheep wool identification, a polymerase chain reaction using specific primer pairs targeting mitochondrial D-loop was developed. The goat specific primers yielded a 294 bp PCR fragment and the sheep specific primers yielded three PCR fragments of which only the 404 bp fragment was found highly diagnostic. The specificity and reliability of the developed species-specific PCR assay was validated by considering as many as 500 cashmere and wool samples. The developed species-specific PCR was found effective in detecting mixed samples of cashmere and wool precisely with the relative content over 9.09%. The species-specific PCR method proved to be low cost, fast, easy and reliable alternative to determine the addition of sheep wool in goat cashmere.