[Dynamic membrane bioreactor with glass fiber tube covered with organic membrane].

A novel grille form complex membrane module composed of glass fiber covered with organic membrane and the dynamic membrane bioreactor (DMBR) with this complex membrane were studied. The results showed that the flux of the dynamic membrane of glass fiber tube without covering with organic membrane solution was only 4 L/(m2 x h) at a trans-membrane pressure (TMP) of 0.02 MPa. After the modification of covering with the organic membrane solution, the complex dynamic membrane flux could reach to a level of 16 L/(m2 x h) at a TMP of 0.01 MPa in operation, and after a hydraulic and chemical cleaning, the membrane flux was up to 17.1 L/(m2 x h) at a lower TMP of 0.003 MPa. When the glass fiber tube was coated with a membrane solution with a concentration of 1:4 (membrane materials/solution in volume ratio), the flux of the complex membrane worked steadily at 14.29 L/(m2 x h) more than 51 days, and according to calculation by TMP rising, the flux could maintain for almost 275 d. The average removal rates of COD and NH4+ -N were 81.96% and 83.66% respectively by the DMBR, and that were 21.01% and 3.61% only by the complex dynamic membrane. Moreover, the cost of complex membrane was approximately 40-60 yuan/m2, which was lower than the traditional organic membrane.

In vivo and in vitro anti-hepatitis B virus activity of total phenolics from Oenanthe javanica.

The traditional Chinese medicine Oenanthe javanica (OJ) has been used for many years, mainly for the treatment of inflammatory conditions including hepatitis. In this study, human hepatoma Hep G2.2.15 cells culture system and duck hepatitis B virus (DHBV) infection model were used as in vivo and in vitro models to evaluate the anti-HBV effects of total phenolics from Oenanthe javanica (OJTP). The HBeAg and HBsAg concentrations in cell culture medium were determined by using the enzyme immunoassay kit after Hep G2.2.15 cells were treated with OJTP for 9 d. DHBV-DNA in duck serum was analyzed by dot blot hybridization assay. In the cell model, OJTP could dose-dependently inhibit the production of the HBeAg and HBsAg, and the inhibition rates of OJTP on HBeAg and HBsAg in the Hep G2.2.15 cells were 70.12% and 72.61% on day 9, respectively. In the DHBV infection model, OJTP also reduced HBV DNA level in a dose-dependent manner. The DHBV-DNA levels decreased significantly after the treatment with 0.10 g kg(-1)d(-1) and 0.20 g kg(-1)d(-1) OJTP. The inhibition of the peak of viremia was at the maximum at the dose of 0.20 g kg(-1)d(-1) and reached 64.10% on day 5 and 66.48% on day 10, respectively. Histopathological evaluation of the liver revealed significant improvement by OJTP. In conclusion, our results demonstrate that OJTP can efficiently inhibit HBV replication in Hep G2.2.15 cells line in vitro and inhibit DHBV replication in ducks in vivo. OJTP therefore warrants further investigation as a potential therapeutic agent for HBV infections.

Inorganic nitrogen removal of toilet wastewater with an airlift external circulation membrane bioreactor.

Removal of inorganic nitrogen (inorganic-N) from toilet wastewater, using a pilot-scale airlift external circulation membrane bioreactor (AEC-MBR) was studied. The results showed that the use of AEC-MBR with limited addition of alkaline reagents and volumetric loading rates of inorganic-N of 0.19-0.40 kg inorganic-N/(m3 x d) helped achieve the desired nitrification and denitrification. Furthermore, the effects of pH and dissolved oxygen (DO) on inorganic-N removal were examined. Under the condition of MLSS at 1.56-2.35 g/L, BOD5/ammonia nitrogen (NH4+ -N) at 1.0, pH at 7.0-7.5, and DO at 1.0-2.0 mg/L, the removal efficiencies of NH4+ -N and inorganic-N were 91.5% and 70.0%, respectively, in the AEC-MBR. The cost of addition of alkaline reagent was approximately 0.5-1.5 RMB yuan/m3, and the energy consumption was approximately 0.72 kWh/m3 at the flux of 8 L/(m2 x h).

Performances of biological aerated filter employing hollow fiber membrane segments of surface-improved poly (sulfone) as biofilm carriers.

Using the surface of poly (sulfone) hollow fiber membrane segments as grafted layer, the hydrophilic acrylamide chain was grafted on by UV-photoinduced grafting polymerization. The gained improvement of surface wettability for the modified membrane was tested by measuring the contact-angle as well as FTIR spectra. Then correlation between the hydrophilic ability of support material and the biofilm adherence ability was demonstrated by comparing the pollutant removal rates from urban wastewater via two identical lab-scale up-flow biological aerated filters, one employed the surface wettability modified poly (sulfone) hollow fiber membrane segment as biofilm carrier and the other employed unmodified membrane segment as biofilm carrier. The experimental results showed that under the conditions of influent flux 5 L/h, hydraulic retention time 9 h and gas to liquid ratio (G/L) 10:1, the removal rates of chemical oxygen demand (COD) and ammonium nitrogen (NH4(+)-N) for the modified packing filter and the unmodified packing filter was averaged at 83.64% and 96.25%, respectively, with the former filter being 5%-20% more than the latter. The effluent concentration of COD, NH4(+)-N and turbidity for the modified packing filter was 25.25 mg/L, 2 mg/L and 8 NTU, respectively. Moreover, the ammonium nitrogen removal performance of the filter packing the modified PSF was compared with the other bioreactor packing of an efficient floating medium. The biomass test indicated that the modified membrane matrixes provided better specific adhesion (3310-5653 mg TSS/L support), which gave a mean of 1000 mg TSS/L more than the unmodified membrane did. In addition, the phenomenon of simultaneous denitrification on the inner surface of the support and nitrification on the outer surface was found in this work.

In vivo and in vitro antiviral activity of hyperoside extracted from Abelmoschus manihot (L) medik.

AIM: To assess the anti-hepatitis B virus (HBV) effect of hyperoside extracted from Abelmoschus manihot (L) medik. METHODS: The human hepatoma Hep G2.2.15 cell culture system and duck hepatitis B virus (DHBV) infection model were used as in vivo and in vitro models to evaluate the anti-HBV effects. RESULTS: In the cell model, the 50% toxic concentration of hyperoside was 0.115 g/L; the maximum nontoxic concentration was 0.05 g/L. On the maximum nontoxic concentrations, the inhibition rates of hyperoside on HBeAg and HBsAg in the 2.2.15 cells were 86.41% and 82.27% on d 8, respectively. In the DHBV infection model, the DHBV-DNA levels decreased significantly in the treatment of 0.05 g x kg(-1 ) x d(-1 ) and 0.10 g x kg(-1) x d(-1) dosage groups of hyperoside (P<0.01). The inhibition of the peak of viremia was at the maximum at the dose of 0.10 g x kg(-1 ) x d(-1) and reached 60.79% on d 10 and 69.78% on d 13, respectively. CONCLUSION: These results suggested that hyperoside is a strong inhibitor of HBsAg and HBeAg secretion in 2.2.15 cells and DHBV-DNA levels in the HBV-infected duck model.

Ultravilolet-radiation-induced graft polymerization of acrylamide onto the melt-blown polypropylene filter element by dynamic method.

By dynamic method under UV irradiation, commercial melt-blown polypropylene (PPMB) filter element was modified with acrylamide (AAm) using benzophenone (BP) as initiator. Attenuated total reflection-Fourier transform infrared spectroscopy and scanning electron microscope verified that polyacrylamide chain was grafted on the fiber surface of PPMB filter element. Elemental content analysis with energy dispersive X-ray of fibers revealed that the polymerization content in the inner part of filter element was relatively higher than that in the outer. Degree of grafting changed with initiator concentration, monomer concentration, reaction temperature and reached 2.6% at the reaction condition: CBP=0.06 mol/L, CAAm=2.0 mol/L, irradiation time: 80 min, temperature: 600 degrees C. Relative water flux altered with the hydrophilicity and pore size of filter element. In the antifouling test, the modified filter gave greater flux recovery (approximately 70%) after filtration of the water extract of Liuweidihuang, suggesting that the fouling layer was more easily reversible due to the hydrophilic nature of the modified filter.

Gas-initiation under UV and liquid-grafting polymerization on the surface of polysulfone hollow fiber ultrafiltration membrane by dynamic method.

Using the inner-surface of polysulfone hollow fiber ultrafiltration membranes as grafted layer, the method of gas-initiation and liquid-polymerization has been studied, which aimed to adjust the diameter of the pores in the membranes. The degree of polymerization varied with the changes of the parameters, such as irradiation time, monomer concentration, temperature and time of polymerization and soon. The results indicated that using benzophenone (BP) which is in a gaseous condition as photo-initiator, acrylamide as graft monomer, the polyacrylamide chain was grafted on the surface of membranes. After the surface membrane being modified, the water flux and retention altered, and thus it can be seen that the diameter of the pores in the membrane was altered. These experiments contribute to finding a new way to produce the hollow fiber membrane with the small pore size and are extraordinarily worth developing and studying.

Effect of Oenanthe javanica flavone on human and duck hepatitis B virus infection.

AIM: To study the antiviral effect of Oenanthe javanica flavones (OjF) on human hepatoma HepG2.2.15 culture system and duck hepatitis B virus (DHBV) infection. METHODS: (1) After incubation for 24 h, the 2.2.15 cells were treated with different concentrations of OjF for 12 d. The cell alteration was observed by microscope. The presence of HBsAg and HBeAg were measured using the enzyme immunoassay kit after 2.2.15 cells were treated with OjF for 9 d. (2) Ducklings infected with DHBV intravenously were divided into 5 groups and treated with OjF, acyclovir (ACV), and normal saline respectively for 10 d. All the ducklings were bled before, during, and after treatments at different times, and serum levels of DHBV-DNA were detected by a dot-blot hybridization assay. RESULTS: (1) The 50% toxic concentration (TC50) of OjF was 2.28 g/L. The maximum nontoxic concentration (TC0) was 1.00 g/L. In nontoxic concentrations, OjF significantly inhibited HBsAg and HBeAg in 2.2.15 cells after 9 d of treatment (P<0.05, P<0.01). (2) The DHBV-DNA levels decreased significantly after the treatment with 0.50 and 1.00 g/kg of OjF (P<0.01). The inhibition of the peak of viremia was maximum at a dose of 1.00 g/kg and reached 54.3% on d 5 and 64.5% on d 10, respectively. CONCLUSION: The results demonstrate that OjF is a strong inhibitor of HBsAg and HBeAg secretion in 2.2.15 cells and DHBV-DNA levels in the HBV-infected duck model.

[Effects of PEG additives on structure and performance of blend membranes].

Polysulfone(PSf) /polymer A blend membranes are fabricated by phase inversion process from casting solution of PSf, polymer A, DMAc, and polyethylene glycol (PEG). The resulting membranes prepared by changing the molecular weight of PEG additives are characterized by scanning electron microscope observation, measurement of water flux and trypsin retention. Experiments of water flux show that water fluxes have non-liner relationship with PEG molecular weight. The water flux of the membrane prepared from the PSf/A/PEG-4000/DMAc casting solution was 115.2mL x (cm2 x h)-1, six time as much as membrane without PEG-0. The PEG as a non-solvent changed thermodynamic properties in polymer solution, promoting phase demixing of casting solution; otherwise, it increased solution viscosity, delaying phase demixing. The two different effects work simultaneously, influencing structure and performance of the membranes.

Photochemical surface modification of poly(arylsulfone) ultrafiltration membrane and covalent immobilization of enzyme.

The sensitivity of poly(arylsulfone) (PSf) for UV irradiation in different solvents (water and ethanol) was investigated. It is confirmed that acrylic acid (AA) and acrylamide (AAm) are grafted only onto the surface of the membrane instead of the interior by FTIR and scanning electron microscope (SEM). The membrane performance (deltaJ/J0 and contact angle theta) after photografting was studied. In the range of conditions used, the grafting yield increases with irradiation time and monomer concentration growing. After photografting and N-3-dimethylaminopropyl-N'-ethycarbodiimide hydrochloride (EDC) activation, PSf membrane was immobilized with hydrogen peroxide oxidoreductase, and showed a higher activity than the control membrane.