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Avian influenza (AI), caused by the influenza A virus, has been a global concern for public health. AI outbreaks not only impact the poultry production, but also give rise to a risk in food safety caused by viral contamination of poultry products in the food supply chain. Distinctions in AI outbreak between strains H5N1 and H7N9 indicate that early detection of the AI virus in poultry is crucial for the effective warning and control of AI to ensure food safety. Therefore, the establishment of a poultry surveillance system for food safety by early detection is urgent and critical. In this article, methods to detect AI virus, including current methods recommended by the World Health Organization (WHO) and the World Organisation for Animal Health (Office International des Epizooties, OIE) and novel techniques not commonly used or commercialized are reviewed and evaluated for feasibility of use in the poultry surveillance system. Conventional methods usually applied for the purpose of AI diagnosis face some practical challenges to establishing a comprehensive poultry surveillance program in the poultry supply chain. Diverse development of new technologies can meet the specific requirements of AI virus detection in various stages or scenarios throughout the poultry supply chain where onsite, rapid and ultrasensitive methods are emphasized. Systematic approaches or integrated methods ought to be employed according to the application scenarios at every stage of the poultry supply chain to prevent AI outbreaks.

The aerobic granules (AGS) were difficult to cultivate and:the degradation kinetics of AGS at low. temperature were seldom investigated, which greatly limited the development and application of AGS. In this study, AGS possessed better settling property and higher biomass after cultivation by sodium acetate for 25 d, furthermore, AGS formation time significantly decreased for 48 d at 10°C in a sequencing batch airlift reactor (SBAR) and AGS possessed better simultaneously COD, NH4+ -N and PO43- -P removal efficiency at low temperature, and the respective removal efficiencies were 84. 5% , 91.1% and 94. 1%. Compared with the conventional cultivation of AGS, the content of total protein was as high as 10. 61 mg/g and the total proteins/total polysaccharides (m(PN)/m(PS)) ratio was 1. 57, which meant that the relative high protein content was an essential feature for AGS formation. The adsorption of organic substances by AGS was higher than that of floc sludge because of the higher contents of EPS, more channels for mass and oxygen transfer as well as the greater specific surface area of AGS. The experimental data indicated that the substances degradation kinetics generally followed Monod equation, the corresponding kinetic coefficient of k and Ks were 5. 49 d-1 and 4 760 mg/L, respectively. The degradation rate of substances was obviously influenced by the mass transfer efficiency between liquid phase and AGS. [ABSTRACT FROM AUTHOR]

A mathematical model on the preparation process of polysilicic acid (PS) was established to joint the bench-scale study with industrialization. Poly-silicic-ferrie (PSF) coagulant was prepared using PS as senti-manufactured goods. PS was prepared using water glass and H2SO4 solution, and mathematical modeling concerning the relationship between gelation time (t) and such factors as pH value, initial w (SiO2) and temperature was presented. The influence of pH value on the species of PS with certain polymerization degree was explored. PSF coagulant was prepared using PS, FeSO4 · 7H2O and NaClO3 by co-polymerization. Both coagulation performance in treating lower temperature, and lower turbidity water by PSF and characteristics of PSF were investigated compared with those of polyferric sulfate (PFS) and poly ferric aluminum (PFA). Results show that some PS is depolymerized after decreasing pH value when PS reaches a certain degree of polymerization, but the species after depolymerization differs from that at the same original pH value. PSF has higher coagulation efficiency than PFS and PFA. The mathematical modeling on the preparation of PS is the basic condition for preparing high quality PSF in industrial scale. The particular characteristics of PSF are just the essential reason for its superior coagulation performance. In the coagulation mechanism of treating low temperature and low turbidity water by PSF, charge - neutralization/destabilization is the precondition and the bridging is the necessary condition. [ABSTRACT FROM AUTHOR]

Organic -- inorganic composite membranes were prepared by phase inversion process using nano-sized alumina (Al2O3) particles as inorganic additive uniformly dispersed in poly(vinylidene fluoride) (PVDF) in order to improve the flux and antifouling performances of PVDF ultrafiltration membrane. Contact angle between water and the membrane surface was measured by contact anglometer in order to characterize the hydrophlicity changing of the membrane surface. Porous dispersion of the membrane surface, the cross-sectional structures and nanometer particles distribution were examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) respectively. Mechanical performances of membranes were measured by omnipotence electronic intensity measuring instrument (W -- 56). Antifouling performance of modified membranes was investigated by an ultrafiltration (UF) cup set. Contaminations on the fouled membranes were analyzed by gas chromatography and mass spectrum. Experimental results indicate that the modified membrane has favorable performances such as water flux, intensity and antifouling performances with 2% addition of nanometer Al2O3 particulars. The addition of nanometer Al2O3 particulars can not affect microstructures of the membrane's surface and cross- section. On the basis of keeping the traits of PVDF organic membranes, surface hydrophlicity properties and antifouling performances of modified membranes are improved significantly due to nano-sized particles addition. [ABSTRACT FROM AUTHOR]

A new type of inorganic polymer, poly-silicic-ferric coagulant with oxidization and with solid and liquid phase coexisting (PSFN) was prepared by adding KMnO4 to the poly-silicic-ferric (PSF) coagulant. The characteristics and the removal efficiency of dissolved organic matters (DOMs) in water by PSFN were explored by both analytical methods and a coagulation test, in comparison with those by PSF and polyferric sulfate (PFS). The solid and liquid components in PSFN were analyzed. The effect of storage time on the stability of coagulation performance of PSFN was investigated. The results show that KMnO4 added to PSF may be a participate in the complexation with Si and Fe, resulting in the difference of the characteristics between PSFN and PSF or PFS, which makes PSFN better in removing DOMs than PSF or PFS. The solid component in PSFN acts as a primary nucleus favoring the formation of flocs, which leads to the formation of larger flocs with sufficient ability of bridging or sweeping. PSFN has better removal efficiency of organic matters (OMs) than the filtrate of PSFN (PSFN-F). The species of PSFN has good stability of coagulation performance. [ABSTRACT FROM AUTHOR]

A model pipeline which dynamically simulates the drinking water distribution system was designed and kept running for twelve months with the tap water from Harbin. Biofilm was taken from its inner surface to isolate and identify the bacteria. Some biofilm was also taken from a real pipeline in Harbin. The results of microbiological analysis showed that there were similar dominant species both in the model and real pipeline, implying that those dominant species could grow well and form the biofilm easily under the same water quality and the same operating situation. The species vary with the length of the test period and reach a balance stage after a long test period. Some biofilm was analyzed by a scanning electron microscope for the further study of the bacterial growth. The SEM results confirmed that most of the bacterial growth on the inner surface of the pipeline were cocci and bacilli. In addition, the polymerase chain reaction (PCR) and agarose gel eletrophoresis were used to detect Pseudomonas aeruginosa. Biofilm samples from the model pipeline and the real distribution pipeline were analyzed by PCR. The PCR result showed that there was no Pseudomonas aeruginosa in both of the pipelines. [ABSTRACT FROM AUTHOR]

Three sequencing batch reactors supplied with different carbon sources were investigated. The system supplied with glucose gained the best enhanced biological phosphorus removal although all of the three reactors were seeded from the same sludge. With the measurement of poly-β-hydroxyalkanoate (PHA) concentration, phosphorus content in sludge and extracellular exopolymers (EPS) with scanning electron microscopy (SEM) combined with energy dispersive spectrometry (EDS), it was found that the biosorption effect of EPS played an important role in phosphorus removal and that the amount of PHA at the end of anaerobic phase was not the only key factor to determine the following phosphorus removal efficiency. [ABSTRACT FROM AUTHOR]

Sorption of ofloxacin (OFL) by carbon nanotubes is an effective method to control its fate in aquatic environment. The sorption process of OFL by mixed acid-treated and non-treated multi-walled carbon nanotubes was discussed. Sorption kinetics, sorption isotherm, desorption, sorption thermodynamics and effect of pH were investigated. The results indicated that the sorption kinetics followed the pseudo-second order kinetics model. The equilibrium sorption capacity of OFL on MWCNTs-O was higher. The sorption isotherm could be fitted by both the Langmuir and Freundlich models. The equilibrium sorption capacity dropped when the pH of aqueous solution was in the range of 6.0 to 10.0. Obvious desorption hysteresis was observed during the desorption experiments, especially on MWCNTs-O. Sorption thermodynamics analysis showed that the interactions between the OFL and sorbents were mainly between molecules. More oxygen-containing functional groups introduced on MWCNTs provided OFL molecules with more sorptive sites, which facilitated the generation of hydrogen bonds, a relatively strong interaction. The hydrogen bonds dominated the sorption process of OFL by MWCNTs/MWCNTs-O, explaining the experimental phenomena.

COD decreased obviously in normal molasses wastewater after anaerobic treatment, however, concentrations of nitrogen and phosphorus were still higher in the effluent which seriously damaged the ecological balance. In this study, aerobic granules cultivated in sequencing batch airlift reactor (SBAR) were carried out for treating the effluent; phosphorus removal processes and characteristics were discussed as well. The mean diameter of aerobic granules cultivated by multiple carbon sources (acetate, propionate and butyrate) was 1.7 mm. The average phosphorus removal efficiency was 90.9% and the level of phosphorus in effluent was only 1.3 mg x L(-1); TP released per COD consumed was 0.571 and the specific rate of TP released was 5.73 mg x (g x h)(-1). NO3(-) -N usage of phosphorus accumulating organisms (PAOs) improved during denitrifying process because the concentration of propionate and butyrate increased in multiple carbon sources which means the phosphorus uptake efficiency increased when per NO3(-) -N consumed. Phosphorus content represented a stronger correlation with magnesium, calcium and ferrum contents in aerobic granules and their extracellular polymeric substances (EPS), the phosphorus adsorption by EPS could enhance phosphorus removal. 61.9% of phosphorus accumulating organisms were denitrifying phosphorus accumulating organisms in aerobic granules and TP uptake per NO3(-) -N consumed was 1.14 which was higher than that of aerobic granules only cultivated by acetate.

An inorganic polymer, poly-silicic-ferric (PSF) coagulant was prepared using water glass, FeSO4 x 7H2O and NaClO3 by copolymerization. A comparison of coagulation performance, distribution of residual flocs in finished water and influence of turbulent shear force on the flocs between PSF and polyferric aluminum (PFA) was explored by jar tests and particle counter approach. The results indicate that PSF has superior removal of COD at higher dose to PFA. Flocculating speed should not be much higher or lower when using PSF as coagulant in treating surface water, and excellent coagulation efficiency can be obtained by the close cooperation of flocculation speed with flocculation time, that is, higher flocculation speed should be consistent with shorter flocculation time. The PFA flocs are much easier destructed than PSF flocs when increasing the turbulent shear force, and the destructed PSF flocs tend to be more easily re-coupled than PFA flocs. From the order magnitude, the flocculation coefficient KA of PSF is from 10(-2) to 10(-3), in comparison with the destruction coefficient KB from 10(-7) to 10(-8). For particles whose size is smaller than 2 microm, KA of PSF is 4 order magnitude more than that of PFA, and KB of PSF is almost the same to that of PFA; while for the other particles, KA of PSF is 2 order magnitude more than that of PFA, and KB of PSF is almost ten times smaller than that of PFA.

The removal effects by PAC-MF integrated system for organic matters, pesticides and ammonia-nitrogen are introduced. The separate contribution of PAC, microorganism and MF in the system are detailed quantitatively. The results indicate that the average removal rates of the integrated process for TOC, UV254, THMFP and HAAFP are 73.56%, 96.75%, 77.64%, 83%, respectively, and 95.1% for pesticides dichlorvos, 98% for ammonia-nitrogen. The results illustrate that PAC significantly reduces the membrane organic burden to 28.32% of the direct membrane filtration without PAC; and carbon layer on the surface of membrane has the removal effect for pollutants. Moreover, the PAC used in high concentration can largely improve its adsorption performance for ammonia-nitrogen, whose removal rate is 44.5%.

A new inorganic polymer coagulant, poly-silic-ferric sulfate (PSF) with various Si/Fe ratios (PSF0.5, PSF1 and PSF denote Si/Fe molar ratios of 0.5, 1 and 3, respectively), was prepared using water glass, ferrous sulfate and sodium chlorate by co-polymerization, and pH value was measured during the preparation process. The influence of both Si/Fe ratio and reaction time (polymerization time) on the complexation process (bonding mode) between Si and Fe was explored with many analytical methods (such as X-ray diffraction (XRD), ultraviolet/visible absorption (UVA) scanning, transmission electron microscope (TEM), photon correlation spectra (PCS) and infrared spectrum (IR) using PSF samples taken from different reaction time at different Si/Fe ratios. The results show that the characteristics of PSF are largely influenced by both reaction time and Si/Fe ratios. PSF is found to be a complexation compound of Si, Fe and many other ions, instead of a simple mixture of raw materials. The complexation process between Si and Fe may be different from various Si/Fe ratios, namely, the bonding rate, bonding mode and the stability of the bond between Si and Fe are different from various Si/Fe ratios: the polymer based on Si-O-Fe-O-Fe-O-Si bond may be formed at low Si/Fe ratio, in comparison with that based on Si-O-Fe-O-Si-O-Si bond at high Si/Fe ratio; the formation rate of Fe-O-Fe bond is rapid and there may be a mutual acceleration between Fe-O-Fe bond and Si-O-Fe bond, while the formation rate of Si-O-Si is slow and maybe there is a mutual retardation between Si-O-Fe bond and Si-O-Si bond; the stability of Fe-O-Fe bond is weaker than that of Si-O-Fe or Si-O-Si bond.

Nano-sized alumina particles as inorganic additive were dispersed in the poly (vinylidene fluoride) uniformly to prepare organic-inorganic composite membranes. Contact angle between water and the membrane surface were measured by contact angle measurement in order to characterize the hydrophilicity changing of the membrane surface. The membrane surface structures, porous distribution on the membrane surface, the cross-sectional structures and nanometer particles distribution were examined by confocal laser scanning microscopy (CLSM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) respectively. Membrane properties were characterized by ultrafiltration (UF) experiments in terms of water flux and antifouling properties. Membranes mechanical performances were measured by omnipotence electronic intensity measuring instrument (W-56). Experiments indicate that Al2 O3 -PVDF composite membranes exhibit significant differences in surface hydrophilicity properties, flux, and intensity and antifouling performances due to nano-sized particles addition.

A new type of inorganic coagulant, solid-liquid oxidative poly silicic ferric sulfate (PSF-I), was prepared by adding KMnO4 and stabilizer M to poly silicic ferric sulfate (PSF). The species characteristics of PSF-I, the filtrate of PSF-I and PSF with spectrophotometer, and coagulation performance of PSF-I and the filtrate of PSF-I with jar tests were explored, respectively. Coagulation efficiency of PSF-I was studied compared to that of PSF and poly ferric sulfate (PFS), and the effect of storage time on coagulation performance of PSF-I was investigated. The results show that KMnO4 added to PSF modifies the microstructure of PSF, increasing species size of PSF and making UVA characteristic peaks of Fe3+ ion in PSF-I higher than that in PSF. There exists KMnO4 unattached in PSF-I. The solid phase in PSF-I is a kind of primary nucleus for building up flocs. The optimal dosage with PSF-I is 9 mg x L(-1), in comparison with 12 mg x L(-1) by PSF-I filtrate. The removal of natural organic matters (NOM) is not only caused by adsorption/charge-neutralization and co-precipitation but also by oxidization using PSF-I as coagulant, while to PSF and PFS, adsorption/charge-neutralization and co-precipitation is the only coagulation mechanism.

The effects of mixture ratio and hydraulic retention time on mesophilic co-digestion of waste activated sludge and kitchen garbage were investigated, and the mixtures having the ratios of 75%:25%, 50%:50% and 25%:75% on a TS basis, operated at the HRTs of 10d, 15d and 20d. In all the digesters, with an OLR 1.53-5.63 g/(L x d), there were no indication of failure, such as low pH, insufficient alkalinity, ammonia inhibition and accumulation of VFAs. The optimum operating conditions of all the digesters were found to be a mixture of 50%:50% in terms of the stability and performance, buffer capacity was the highest. The volatile solid removal efficiency, specific methane production and methane content in this condition achieved 51.1%-56.4%, 0.353-0.373 L/g and 61.8%-67.4%.

To investigate the microbial communities of microorganisms cultivated under different carbon sources, three sequencing batch reactors were operated. They were supplied with sewage, glucose and sodium acetate as carbon sources respectively and showed high phosphorus removal performance. The results of denaturing gradient gel electrophoresis (DGGE) of polymerase chain reaction-amplified (PCR) 16S rDNA fragments demonstrated that beta-protebacteria, Actinomyces sp. and gamma-protebacteria only exited in 1 # reactor. The microbiological diversity of 1 # reactor exceeded the other two reactors. Flavobacterium, Bacillales, Actinomyces, Actinobacteridae and uncultured bacteria (AF527584, AF502204, AY592749, AB076862, AJ619051, AF495454 and AY133070) could be detected in the biological phosphorus removal reactors.