Comparison of membrane fouling during short-term filtration of aerobic granular sludge and activated sludge

Aerobic granular sludge was cultivated adopting internal-circulate sequencing batch airlift reactor. The contradistinctive experiment about short-term membrane fouling between aerobic granular sludge system and activated sludge system were investigated. The membrane foulants was also characterized by Fourier transform infrared （FTIR） spectroscopy technique. The results showed that the aerobic granular sludge had excellent denitrification ability; the removal efficiency of TN could reach 90%. The aerobic granular sludge could alleviate membrane fouling effectively. The steady membrane flux of aerobic granular sludge was twice as much as that of activated sludge system. In addition, it was found that the aerobic granular sludge could result in severe membrane pore-blocking, however, the activated sludge could cause severe cake fouling. The major components of the foulants were identified as comprising of proteins and polysaccharide materials.

Simultaneous removal of COD and nitrogen using a novel carbon-membrane aerated biofilm reactor

A membrane aerated biofilm reactor is a promising technology for wastewater treatment. In this study, a carbon-membrane aerated biofilm reactor （CMABR） has been developed, to remove carbon organics and nitrogen simultaneously from one reactor. The results showed that CMABR has a high chemical oxygen demand （COD） and nitrogen removal efficiency, as it is operated with a hydraulic retention time （HRT） of 20 h, and it also showed a perfect performance, even if the HRT was shortened to 12 h. In this period, the removal efficiencies of COD, ammonia nitrogen （NH4^＋-N）, and total nitrogen （TN） reached 86%, 94%, and 84%, respectively. However, the removal efficiencies of NH4^＋-N and TN declined rapidly as the HRT was shortened to 8 h. This is because of the excessive growth of biomass on the nonwoven fiber and very high organic loading rate. The fluorescence in situ hybridization （FISH） analysis indicated that the ammonia oxidizing bacteria （AOB） were mainly distributed in the inner layer of the biofilm. The coexistence of AOB and eubacteria in one biofilm can enhance the simultaneous removal of COD and nitrogen.

PEGylation of Hirudin and Analysis of Its Antithrombin Activity in vitro

Hirudin is the most anticoagulant drug found in nature, but its short serum half-life significantly inhibits its clinical anpplication. The PEGvlation of hirudin, the most promising anticoagulant drug, was performed in this paper. The optimal reaction conditions for PEG ylated hirudin were investigated, wh.en the PEGylation react, on.wasconducted under 4℃ after 10h, in the borate buffer at pH 8.5 .with the molar ratio 230 ： 1 of PEG to hirudin, a higher modification extent was achieved. Finally, the bioactivity of PEGylated hirudin was measured in vitro.Compared with unmodified hirudin, 26% of anti-thrombin activity was retained.

Effect of substrate COD/N ratio on performance and microbial community structure of a membrane aerated biofilm reactor

Two parallel carbon-membrane aerated biofilm reactors were operated at well-defined conditions to investigate the effect of substrate COD/N ratios on the performance and microbial community structure of the bioreactor. Results showed that at substrate COD/N of 5, organic and nitrogen could be eliminated simultaneously, and COD removal degree, nitrification and denitrification efficiency reached 85%, 93% and 92%, respectively. With increasing substrate COD/N ratios, the specific oxygen utilization rates of nitrifying bacteria in biofilm were found to decrease, indicating that nitrifying population became less dominant. At substrate COD/N ratio of 6, excessive heterotrophs inhibited the activity of nitrifying bacteria greatly and thus led to poor nitrification process. With the help of fluorescence in situ hybridization （FISH）, Nitrosomonas and Nitrosospira were identified as dominant ammonia-oxidizing bacteria in the biofilm at substrate COD/N of 0, whereas only Nitrosospira were detected in the biofilm at COD/N ratio of 5. Nitrospira were present as dominant nitrite-oxidizing bacteria in our study. Confocal laser scanning microscopy images revealed that at substrate COD/N ratio of 0 nitrifying bacteria existed throughout the biofilm and that at COD/N ratio of 5 they were mainly distributed in the inner layer of biofilm.

Establishment and Application of Urbanization Strategic Environ-mental Assessment Integration Technology System

Urbanization strategic environmental assessment (SEA) is an effective instrument to enhance the harmo-nious development of urban complex system, integrating of environment and development in decision-making. Ur-banization strategic environmental assessment integration technology system (SEA-ITS) is composed of "3S" (RS, GIS and GPS), environmental expert system and environmental model system, coupling with appropriate SEA working process closely. In this paper, the structure and components of SEA-ITS are analyzed based on Chinese characteristics, meanwhile methods to fulfill the following system functions are discussed: urbanization SEA in-quiring, analysis, discrimination, assessment, prediction, decision-making and output. Moreover, methods and tech-nologies employed in different urbanization SEA hierarchies are summarized. As a case study, urbanization SEA-ITS is applied in Changchun City to solving complex real problems. Methods such as system dynamics and grey cluster are adopted to achieve the environmental impact assessment on the eco-industrial system planning. It is revealed that the system designed is capable of reflecting the dynamic behavior of eco-industrial system under different sce-narios, meanwhile accomplishing strategy optimization and supplying scientific reference. The 4th strategy, namely concerning on economy increase and its interaction with science, technology and environment progress, would have the best efficiency. Further, more attention should be paid to the secondary development of integration techniques and function modification system of urbanization SEA-ITS.

Non-UV germicidal activity of fresh TiO_2 and Ag/TiO_2

Fresh TiO2 was found to possess a strong germicidal activity even without UV irradiation. Live Yeast （Saccharomyces cerevisiae） cells in contact with fresh TiO2 were found deformed and dead after 15min contact. The cause of germicidal activity was discussed from the observed cell deformation, lysis and increased absorption at 1680 cm^-1 in FT-IR spectra of the affected cells, which proved the oxidizing effect of fresh TiO2 to cells. The deformation caused by the stretching of cell wail and pressure built-up inside the cell, led to cell burst and release of intracellular materials. The degree of cell deformation was found positively related with the wetting property of TiO2. Cells are negatively charged, for Gram-negative cell （thinner ceil wail）, a higher germicidal effect was observed than Gram-positive cells. The germicidal effect of TiO2 gradually decreased after exposure to air at room temperature, as the wetting property decreased. This kind of germicidal activity was more effective compared to other germicidal process such as UVA/TiO2 or Ag＋. This shed light on designing new germicidal material either maintained by visible light irradiation, or by oxidation effect generated by reactive oxygen species.

Safety Properties and Probiotic Potential of Bacillus subtilis KATMIRA1933 and Bacillus amyloliquefaciens B-1895

This study reports on the safety and putative probiotic properties of Bacillus amyloliquefaciens B-1895 and Bacillus subtilis KATMIRA1933. According to the bacterial reverse mutation (Ames) test, cell-free supernatants of B. amyloliquefaciens B-1895 and B. subtilis KATMIRA1933 were not mutagenic. The two strains co-aggregated with Escherichia coli and Pseudomonas aeruginosa, and cell-free supernatants inhibited the growth of Streptococcus intermedius and Porphyromonas gingivalis. Endospores of B. amyloliquefaciens B-1895 and B. subtilis KATMIRA1933 were tolerant to 0.3% (w/v) bile salts and survived incubation for 4 h in MRS broth at pH 2.0 to 3.0. The ability of the two strains to produce antimicrobial compounds potentiates their application in health care formulations, personal care products, food and animal feed.

Relation of asid- volatile sulfide and clay content of sediment to the bioavailability of zinc and cadmium:laboratory plus field experiment

Organic matter and iron and maganese oxides have been considered as the major affecting factors for metals in anoxic or oxidized sediment. In recent research, clay and sulfide are found as major factors in oxic or oxidized sediments that might affect bioavailability of metals. To test this hypothesis, the influence of sulfide, measured as acid-volatile sulfide （AVS）, and clay content on the bioavailability of zinc and cadmium in sediments was examined. Laboratory simulative experiment and field verification experiment were conducted, showing that the bioavailability of zinc and cadmium is strongly correlated to AVS and clay content in sediments. Taking into account both AVS and clay parameters in sediments together can better indicate the bioavailability of zinc and cadmium rather than considering one of them alone.

Solvent Effect on Conformation of a Cycloheptapeptide,Stylopeptide 1,Evaluated by Molecular Dynamics in Methonal and Aqueous Environments

Stylopeptide 1 synthesized and isolated from different sources exhibits a large activity difference in inhibitory effect on the growth of a cancer cell.Based on the different amounts of methanol and water during synthesis,isolation and purification of the cyclic peptides,molecular dynamics(MD) was employed to simulate the conformation of stylopeptide 1 in methanol and aqueous environments.The comparative results show that the backbone ring was more rigid in methanol than in water.In methanol,two β-turns and three hydrogen bonds were well conserved throughout the simulation,whereas no hydrogen bonds or turns were preserved in water.The activity difference of stylopeptide 1 seemed to be attributed to the solvent effect on its conformation.

Urban Wetlands:An Opportunity for Environmental Conservation in China

China's remarkable economic growth and transformation in recent years has been a model for the world, but like all other expanding economies there have been accompanying environmental problems. For more than 5,000 years, however, China has proven that it can cope with problems and remain a vibrant society. China is now turning its attention to the environment through efforts to conserve endangered species, create protected areas, use renewable energy, reforest the margins of deserts, control air pollution, rehabilitate ecosystems, develop ecological agriculture, promote ecotourism, and safeguard its supplies of fresh water. Some of these efforts have had more success than others. The restoration and protection of urban wetlands offers a unique opportunity to meet many of these environmental challenges simultaneously, including the enhancement of the awareness and appreciation of nature and natural processes among urban populations, especially children, upon whom the future of China's environmental movement depends. The United States is facing similar challenges in its urban areas, and some of its recent approaches to dealing with nature in cities may provide useful guidelines.

Catalpol Upregulates Hippocampal GAP-43 Level of Aged Rats with Enhanced Spatial Memory and Behavior Response

Rehmannia glutinosa is a traditional Chinese medical herb and has a long history in cognitive deficits therapy. Its ther-apeutic efficacy has been confirmed by clinical studies. In this study, we attempted to investigate the effects of catalpol, an iridoid from Rehmannia glutinosa, on cognitive and behavioral function of aged rats with memory loss. 22 - 24 month Sprague-Dawley spontaneous rats of memory loss with aging were selected by step-down type passive avoidance test and randomly allocated to two groups: the aged rats with memory loss (control group) and the catal- pol-treated (5 mg/kg) group. We performed open-field and Y-maze test to evaluate special performance and behavior response before and after catalpol treatment for 5 and 10 days. Growth-associated protein (GAP-43) in hippocampus and frontal cortex was measured using immunohistochemistry and quantitative Western Blotting. The results showed that catalpol could significantly improve not only spatial learning and memory but also locomotor activity and ex-plora- tory behavior of aged rats with memory loss. GAP-43 protein in hippocampal CA3 region and dentate granule of catal- pol-treated rats was significantly enhanced than that of control group. Western blot analysis demonstrated a catal- pol-associated increase of GAP-43 in hippocampus of catalpol-treated rats and correlated with spatial memory, loco- motor activity and exploratory behavior. However, there was no difference in GAP-43 protein in frontal cortex between two groups. These results indicated that catalpol could enhance spatial performance and behavioral responses in aged rats with memory loss, and the mechanism may involve up-regulation of GAP-43 level of hippocampus in the brain. It also suggested that catalpol may be a useful natural drug for Alzheimer’s disease (AD) treatment by modulating hippo- campal neuroplasticity.

Intercalation,Cytotoxicity,and Molecular Modeling of Acenaphtho[1,2-b]pyrrole Chromophores as a New Family of Antitumor Agents

To explore new platform for DNA intercalation and potent antitumor agent, a series of 8-oxo-8H- acenaphtho[1,2-b]pyrrole-9-carboxylic acid esters chromophores has been studied. Their intercalation geometries with DNA were rex;ealed through absorption titration, SYBR Green-DNA melt curve, circular dichroism（CD）, and docking studies. It was identified that some of the compounds could intercalate into DNA along their long axis parallel to the base-pair long axis, making right-handed B form DNA transform to A-like conformation. Their binding potency varied with the different steric hindrance. Their cytotoxicity（IC50） against MCF-7 cells was found to range between 1.3 to 40.9 umol/L by MTT assay. Interestingly, the IC50 values did not show any obvious correlation to their binding constants with DNA. The chromophore with a carboxyl group exhibited the most potency of intercalating DNA and could be the promising precursor for the future intercalator for DNA, while the bromide demonstrated the highest cytotoxic activity in this series of compounds.

Reproductive Mode of Fejervarya limnocharis (Anura:Ranidae) Caught from Mae Sot,Thailand Based on Its Gonadosomatic Indices

Amphibians show a variety of reproductive modes and strategies. The cyclicity and continuity of reproduction can often be predicted from the annual gonadosomatic index trends in a species specific manner. This research aims to document the female and male gonadosomatic index profiles and to ascertain the reproductive cyclicity or continuity of Fejervarya lirnnocharis （Anura： Ranidae） caught in Mac Sot, Tak Province, Thailand. Frogs were collected monthly between November 2007 and October 2009 in rice fields and their surrounding areas in the study site. For each frog, total weight and ovarian/testicular weight were measured to obtain the female and male gonadosomatic index. The number of female individuals with mature eggs （postvitellogenic eggs） was also counted. The results showed that female frogs had two main surges of increased GSI in March and September of 2008. Alternatively, male frogs showed a more gradual increase and decrease in gonadosomatic index, thus the index remaining high throughout the year. This study concluded that while F. limnocharis in this area is essentially a continuous breeder, it is more optimized for a cyclic reproduction mode with two breeding cycles during the rainy season.

Effects of Reed Rootstocks on Hydraulic Properties of Surface Soil in the Shuangtai Estuary Wetland, Northeast China

A set of field experiments was conducted to investigate the effects of reed rootstocks on hydraulic properties of surface soils in the Shuangtai Estuary Wetland, Northeast China. The soil particle size distribution and rootstock content were analyzed, and the vertical soil water profile was monitored by using a multisensory capacitance system. Hydraulic conductivity of the surface soil layer was estimated by in si-tu infiltration. The soil was silt loam with less sand; soil texture was consistent though the vertical profile, but bulk density was lower in the upper 20 era, where the fine roots were concentrated. The surface soil moisture profile changed dynamically, and variation in vertically integrated soil moisture was consistent with observed precipitation and estimated evaporation. Infiltration capacity was 30 cm＇d＂~, much larger than typical hydraulic conductivity values for silt loam with less sand. These findings suggest that fine annual roots change the soil matrix and hydraulic conductivity in surface soils. A vertical one-dimensional water transport model was presented based on Richard＇s equation. Model parameters were estimated from the soil analyses and literature data. The computation accurately reproduced the dynamic changes in moisture in surface soils containing large volumes of fine rootstock.

Catalytic reductive dechlorination of p-chlorophenol in water using Ni/Fe nanoscale particles

Nanoscale bimetallic Ni/Fe particles were synthesized from the reaction of sodium borohydride （NaBH4） with reduction of Ni^2＋ and Fe^2＋ in aqueous solution. The obtained Ni/Fe particles were characterized by TEM （transmission electron microscope）, XRD （X-ray diffractometer）, and N2-BET. The dechlorination activity of the Ni/Fe was investigated using p-chlorophenol （p-CP） as a probe agent. Results demonstrated that the nanoscale Ni/Fe could effectively dechlorinate p-CP at relatively low metal to solution ratio of 0.4 g/L （Ni 5 wt%）. The target with initial concentration ofp-CP 0.625 mmol/L was dechlorinted completely in 60 rain under ambient temperature and pressure. Factors affecting dechlorination efficiency, including reaction temperature, pH, Ni loading percentage over Fe, and metal to solution ratio, were investigated. The possible mechanism of dechlorination ofp-CP was proposed and discussed. The pseudo-first- order reaction took place on the surface of the Ni/Fe bimetallic particles, and the activation energy of the dechlorination reaction was determined to be 21.2 kJ/mol at the temperature rang of 287-313 K.

Adsorption behavior of Azo Dye C. I. Acid Red 14 in aqueous solution on surface soils

Azo dyes have received considerable attention because of their association with various human health problems. The aim of the investigation is to determine the adsorption behavior ofazo dyes in aqueous solution on DG06, GSE17200, and GSE17201 soils using C. I. Acid Red 14 （AR14） as example. The experimental results indicate that the Freundlich model expresses the adsorption isotherm better than the Langmuir model and the pseudo-second-order model achieves adsorption of AR14 on the three soils well. Based on the pseudo-second-order model, the adsorption thermodynamic of AR14 on DG06 soil have been studied and the thermodynamics parameter of AGO is determined and AGO value shows the adsorption process of AR14 on DG06 is mainly physical in nature. Furthermore, the effects of temperature, pH and salinity （NaC1） on adsorption have been investigated. The decrease in pH or the increase in salinity enhances the adsorption of AR14 by DG06, GSE17200, and GSE17201.

Degradation induces changes in the soil C:N:P stoichiometry of alpine steppe on the Tibetan Plateau

Due to the Tibetan Plateau’s unique high altitude and low temperature climate conditions,the region’s alpine steppe ecosystem is highly fragile and is suffering from severe degradation under the stress of increasing population,overgrazing,and climate change.The soil stoichiometry,a crucial part of ecological stoichiometry,provides a fundamental approach for understanding ecosystem processes by examining the relative proportions and balance of the three elements.Understanding the impact of degradation on the soil stoichiometry is vital for conservation and management in the alpine steppe on the Tibetan Plateau.This study aims to examine the response of soil stoichiometry to degradation and explore the underlying biotic and abiotic mechanisms in the alpine steppe.We conducted a field survey in a sequent degraded alpine steppe with seven levels inNorthern Tibet.The plant species,aboveground biomass,and physical and chemical soil properties such as the moisture content,temperature,pH,compactness,total carbon(C),total nitrogen(N),and total phosphorus(P)were measured and recorded.The results showed that the contents of soil C/N,C/P,and N/P consistently decreased along intensifying degradation gradients.Using regression analysis and a structural equation model(SEM),we found that the C/N,C/P,and N/P ratios were positively affected by the soil compactness,soil moisture content and species richness of graminoids but negatively affected by soil pH and the proportion of aboveground biomass of forbs.The soil temperature had a negative effect on the C/N ratio but showed positive effect on the C/P and N/P ratios.The current study shows that degradation-induced changes in abiotic and biotic conditions such as soil warming and drying,which accelerated the soil organic carbon mineralization,as well as the increase in the proportion of forbs,whichwere difficult to decompose and input less organic carbon into soil,resulted in the decreases in soil C/N,C/P,and N/P contents to a great extent.Our results provide a sound basis for sustainable conservation and management of the alpine steppe.

Decolorization of azo dyes with high salt concentration by salt-tolerant mixed cultures under anaerobic conditions

Because the lack of detailed study of biological decolorization in high salt dye wastewater, it is still difficult to evaluate the biological treatment on high-salinity dye wastewater. The experiments were carried out to study the salt-tolerant bacteria, which is useful in the treatment of high-salinity colored wastewater. Simulated wastewater containing 5-150 g/L salt （NaCI） and 50-2000 mg/L Reactive Brilliant Red K-2BP was treated with three salt-tolerant mixed cultures （CAS, TAS, DSAS）, which were under a gradually acclimated procedure. With the increase of concentrations of salt and dye, the decolorization became low. The abilities of decolorization of dyes wastewater by three mixed cultures （CAS, TAS, DSAS） were studied, CAS and DSAS mixed cultures showed more active for the treatment of high-salinity colored wastewater than TAS mixed cultures. The results suggested that there might be a simple process for the high salt wastewater treatment, which could be incorporated into conventional activated sludge plants.

Degradation of Organic Compounds by Active Species Sprayed in a Dielectric Barrier Corona Discharge System

Investigation was made into the degradation of organic compounds by a dielectric barrier corona discharge （DBCD） system. The DBCD, consisting of a quartz tube, a concentric high voltage electrode and a net wrapped to the external wall （used as ground electrode）, was introduced to generate active species which were sprayed into the organic solution through an aerator fixed on the bottom of the tube. The effect of four factors-the discharge voltage, gas flow rate, solution conductivity, and pH of wastewater, on the degradation efficiency of phenol was assessed. The obtained results demonstrated that this process was an effective method for phenol degradation. The degradation rate was enhanced with the increase in power supplied. The degradation efficiency in alkaline conditions was higher than those in acid and neutral conditions. The optimal gas flow rate for phenol degradation in the system was 1.6 L/min, while the solution conductivity had little effect on the degradation.

The Response of Vegetation Biomass to Soil Properties along Degradation Gradients of Alpine Meadow at Zoige Plateau

Alpine grassland of the Tibetan Plateau has undergone severe degradation, even desertification. However, several questions remain to be answered, especially the response mechanisms of vegetation biomass to soil properties. In this study, an experiment on degradation gradients was conducted in an alpine meadow at the Zoige Plateau in 2017. Both vegetation characteristics and soil properties were observed during the peak season of plant growth. The classification and regression tree model(CART) and structural equation modelling(SEM) were applied to screen the main factors that govern the vegetation dynamics and explore the interaction of these screened factors. Both aboveground biomass(AGB) and belowground biomass(BGB) experienced a remarkable decrease along the degradation gradients. All soil properties experienced significant variations along the degradation gradients at the 0.05 significance level. Soil physical and chemical properties explained 54.78% of the variation in vegetation biomass along the degradation gradients. AGB was mainly influenced by soil water content(SWC), soil bulk density(SBD), soil organic carbon(SOC), soil total nitrogen(STN), and pH. Soil available nitrogen(SAN), SOC and p H, had significant influence on BGB. Most soil properties had positive effects on AGB and BGB, while SBD and p H had a slightly negative effect on AGB and BGB. The correlations of SWC with AGB and BGB were relatively less significant than those of other soil properties. Our results highlighted that the soil properties played important roles in regulating vegetation dynamics along the degradation gradients and that SWC is not the main factor limiting plant growth in the humid Zoige region. Our results can provide guidance for the restoration and improvement of degraded alpine grasslands on the Tibetan Plateau.