[Rapid Start-up of One-stage Autotrophic Nitrogen Removal Process in EGSB Reactor for Wastewater with Low Concentration of Ammonia].

Biofilm coming from a reactor in which One-stage Autotrophic Nitrogen Removal Process exists was selected as inoculum in an expanded granular sludge bed reactor. A potential fast start-up procedure was tested in this research. Wastewater with low ammonium concentration between 60-100 mg·L-1 was applied. The results showed that a One-stage Autotrophic Nitrogen Removal Process was successfully established in 83 days under the following conditions: temperature at (30±2)℃ , pH at 7.8-8.2, dissolved oxygen (DO) at 0.2-1.1mg·L-1 and upflow velocity at 2.0-4.0m·h-1. After the 83-day operation, the removal efficiencies of NH4+-N and TN were 99.4% and 80.7%, respectively. By controlling the reflux ratio and increasing the NH4+-N load, the reactor could maintain a stable state of low DO concentration. Nitrification and anaerobic ammonium oxidation became main reactions that maintained efficient and stable nitrogen removal performance. In addition, nitrite-oxidizing bacteria (NOB) were inhibited. In the start-up process, the average particle diameter of granular sludge increased from 174 to 296 µm. Moreover, scanning electron microscopy showed that the surface of granular sludge was smooth, and most microorganisms were bevibacteria and cocci. Finally, a fluorescence in situ hybridization experiment showed that ammonium oxidation bacteria and anaerobic ammonium oxidation bacteria were distributed on the surface and in the inner space of granular sludge, respectively. The research indicated that a stable autotrophic nitrogen removal granular sludge system was quickly established in the sludge bed.

Anti-adenovirus activities of shikonin, a component of Chinese herbal medicine in vitro.

Radix Lithosperm eyrthrorhizon is a common prescription compound in traditional Chinese medicine. Shikonin is a major component of Radix Lithospermi and has various biological activities. We have investigated the inhibitory effect of shikonin on the growth of adenovirus type 3 (AdV3) in vitro. The antiviral function of shikonin against AdV3 and its virus inhibition ratio were detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method (MTT). The expression of hexon protein in AdV3 was determined by immunofluorescence assay using laser scanning confocal microscopy (LSCM) and Western blot analysis. In addition, the rate of apoptosis in cells infected by AdV3 was determined by flow cytometry. Shikonin (0.0156-1 µM) inhibited growth of AdV3 in a concentration-dependent manner with a virus inhibition rate of 23.8-69.1%. Expression of hexon protein in AdV3 was higher in the virus control group than in the shikonin-treated groups as determined by immunofluorescence assay and Western blotting (p<0.05). The rate of shikonin-treated HeLa cell apoptosis had a statistically significant decrease with increasing concentration of drug (p<0.05). Our data demonstrate that shikonin possesses anti-AdV3 capabilities and that the potential antiviral mechanism might involve inhibiting the degree of apoptosis and hexon protein expression of AdV.