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In this paper, the performance of membrane bioreactors (MBR) and conventional activated sludge (CAS) processes at low temperature was investigated by analyzing their effluent quality and microbial viability. 454 high-throughput pyrosequencing was also applied to study the microbial community structures. The results of three systems (two MBRs: R1 with high sludge concentration, R2 with low sludge concentration, and one CAS: R3) showed that the average removal rate of NH4(+) -N was 99.7%, 99.7% and 59.7%, respectively, and the average removal rate of TN was 85.2%, 56.1% and 58.8%, respectively. R2 showed the highest specific ammonium uptake rate (SAUR), followed by R1 and R3; R1 showed the highest specific nitrate uptake rate (SNUR), followed by R2 and R3. It could be concluded that MBRs with high sludge concentration had a better performance of nitrogen removal under low temperature operation. 454 high-throughput pyrosequencing analysis revealed that the microbial richness was R2 > R3 > R1, and the microbial diversity was R2 > R1 > R3 at 97% sequence identity. The microbial structure and bacterial abundance were quite different between MBR and CAS systems. The dominant nitrifier in this research was Nitrospira, and the total relative abundance of nitrifiers in R1, R2, R3 was 1.22%, 1.64% and 0.15%, respectively. The Zoogloea, Thauera, Comamonadaceae and Comamonas might be the dominant denitrifers in this study, and the total relative abundance of denitrifier in R1, R2, and R3 was 5.8%, 4.52% and 15.21% respectively. MBR's characteristics of long solid retention time, high sludge concentration and low total nitrogen loading well supported the accumulation of nitrifiers and denitrifiers, and improved the performance of biological nitrogen removal at low temperature.

The properties of membrane foulants in MBR treating high-salinity wastewater were studied. Results showed that the removal efficiency of organics and NH4(+) -N was stable and high-quality effluent was obtained after the operation time of 121 d; the ratio of VSS/ SS decreased and SVI declined at the same time, indicating that the inorganic content of sludge increased which might lead to more compact flocs and higher settling ability; SMP and EPS of the sludge were largely changed with a lower proportion of protein and a higher proportion of humic acid. Scanning electron microscope-energy diffusive X-ray analyzer (SEM-EDX) demonstrated that Na, Al, Mg, Ca, K, Fe, Ti, Cr, W, Si and Cl were the major inorganic elements in membrane foulants; Gel filtration chromatography (GFC) illustrated that there were organic matters with high molecular weight trapped by membrane and formed the membrane foulants; Fourier transform infrared (FTIR) spectroscopy and Excitation emission matrix (EEM) fluoresce spectroscopy discovered that carbohydrates, protein and humic acid were the main content of organics in membrane foulants.; quantitative analysis of membrane foulants showed that the amount of inorganic membrane foulants were significant when treating high-salinity wastewater.

Mathematical modeling is a useful tool for professional education, process development, design evaluation, operational optimization and automatic control of the wastewater treatment system, and has been extensively applied in numerous full-scale wastewater treatment plants. The ASM2d model was calibrated by the process data, and used to simulate 15 operational test runs of the multimode anaerobic/anoxic/aerobic (AAO) process. After calibration, the model was capable of simulating the sludge concentrations and effluent data in 15 test runs of the multimode AAO system. The dynamic simulation results showed an overall good agreement between the measured and simulated data, for both effluent data and sludge concentrations, with a good reproduction of dynamic processes in AO test runs.

Seasonal freeze-thaw cycle and its change pattern under the scenarios of climate warming might exert strong effects on the soil nitrogen mineralization in alpine forests. In this paper, intact soil cores were collected from the subalpine/alpine forests along an altitudinal gradient in west Sichuan, and an incubation test was conducted to study the soil net nitrogen mineralization rate and the amount of soil mineralized nitrogen in the forests during growth season and seasonal freeze-thaw period under simulated scenarios of global warming. In the test soils, the NH(4+)-N and NO(3-)-N contents both showed a clear tendency of decreased in the period from growth season to the onset stage of freezing, increased at deep freezing stage, and decreased again at the early stage of thawing. The soil net nitrogen mineralization rate and the amount of soil mineralized nitrogen were significantly lower in freeze-thaw period than in growth season, and the soil inorganic nitrogen was obviously immobilized. The soil nitrogen immobilization was stronger at middle altitudes but weaker at high altitudes, as compared with that at low altitudes, possibly due to the variation of soil temperature and its induced different freeze-thaw cycle. During growth period, the soil net nitrogen mineralization rate and the amount of soil mineralized nitrogen showed an obvious increasing trend with the decrease of altitude, and the soil nitrogen mineralization was the strongest at low altitudes, implying that under the scenarios of climate warming, the increase of soil temperature promoted the soil nitrogen mineralization during growth season, and affected the soil nitrogen mineralization rate by increasing the frequency of freeze-thaw cycle and shortening the time period of freeze-thaw. Soil micro-environment could also affect the soil nitrogen mineralization in alpine forest regions.

Objective: To study the impact of two human glioma tissue resistance genes MGMT and ERCC(2) on the temozolomide-based treatment of malignant gliomas and detect the relationship of their expressions., Methods: A total of 58 malignant glioma patients aged 19 - 68 years old receiving a chemotherapy of temozolomide were followed up and classified as non-sensitive group (n = 30) and sensitive group (n = 28). Immunohistochemistry was employed to detect the expression rates of MGMT and ERCC(2). And the correlation between the expressions of two genes was analyzed by immunohistochemistry and RT-PCR (reverse transcription-polymerase chain reaction)., Results: The expression rates of MGMT and ERCC(2) were 10.71% and 3.57% in the sensitive group and 63.33% and 56.67% in the non-sensitive group. It had an obvious correlation with the expressions of MEGT and ERCC(2) through an analysis of immunohistochemistry and RT-PCR (both P < 0.01)., Conclusion: The expressions of MGMT and ERCC(2) in the sensitive group are markedly lower than those in the non-sensitive group. The expression of two genes may be related to tumor prognosis. Maybe these two genes have an intrinsic link between their expressions. Both participate in the repair of cellular DNA damage and the formation of tumor drug resistance. And the prognosis has obvious relevance.

The successful application of activated sludge model (ASM) in wastewater treatment plant mainly depends on the correctness of wastewater fractionation. Based on three batch oxygen uptake rate (OUR) tests, a COD fractionation protocol and the corresponding Matlab program were developed to aid the standardization of COD fractionation in wastewater. COD fractionation results of two wastewater treatment plants (WWTP) in Shanghai show that COD in wastewater of the Quyang WWTP is composed of 8.1% +/- 1.6% readily biodegradable COD (S(s)), 6.3% +/- 2.2% soluble inert COD (S(I)), 45.5% +/- 3.5% slowly biodegradable COD (X(S)), 31.1% +/- 2.1% particulate inert COD (X(I)) and 9.0% +/- 1.1% heterotrophic biomass (X(H)), and those fractions in wastewater of the Bailonggang WWTP are 11.1% +/- 2.2%, 9.9% +/- 2.0%, 38.9% +/- 10.7%, 23.3% +/- 9.8% and 16.9% +/- 1.8%, respectively. Compared to the Quyang WWTP, wastewater of the Bailonggang WWTP showed lower X(S) and X(I) contents in COD, but greatly higher X(H)/COD value, indicating that long pipeline transportation could significantly influence the concentration of COD fractions.

A fractionation protocol of soluble COD (SCOD) was put forward by combining respirometric method with hydrolysis kinetics of soluble slowly biodegradable COD (S(H)). SCOD fractionation results of two wastewater treatment plants (WWTP) in Shanghai show that the SCOD in sand basin effluents (typical domestic wastewater) of WWTP A is composed of 43.5%-58.6% S(H), 21.8%-35.2% readily biodegradable COD (S(S)) and 15.4%-30.9% soluble inert COD (S(I)), and those SCOD fractions in sand basin effluents (combined sewers after long pipeline transportation) of WWTP B are 34.5%-45.2%, 29.3%-37.7% and 25.6%-31.2%, respectively. The linear regression results of respirometric tests data from nine samples demonstrate that the first-order kinetics can reliably describe hydrolysis process of S(H), and the kinetic constants of S(H) from WWTP A and B are respectively 28.00-39.77 d(-1) and 26.48-29.52 d(-1). Experimental results demonstrate that this protocol can achieve theoretical partition for the integration area of S(S), and also eliminate the effect of soluble microbial products on S(I) determination.