Advanced Materials Research Vols. 518-523

Abstract: The impact of intermittent aeration on aerobic granular sludge in a continuous flow reactor was studied. Nine intermittent aeration modes were set up to investigate the change of DO, pH, COD removal efficiency and SOUR. The results showed DO and pH had different change tendencies. The 3-1 mode was the optimal mode under these experiment conditions. In aerating stage, the highest COD removal efficiency could achieve 96.32%. Stopping aeration for one hour, COD removal efficiency could still reach at 90.20%. This operation mode could save about 25% energy consumption theoretically. The comparison of SOUR between continuous aeration and 4-2 mode showed that the intermittent aeration had little effect on granular sludge activity. The theory of stress & damage and unbalanced growth could explain this appearance.

Abstract: Nitrogen deposition input changes the carbon and nitrogen cycle rate significantly in terrestrial ecosystem, and then affects the structure and function of entire ecosystem. The elevated atmospheric concentration of greenhouse gases is one of the most important causes of global warming and has become an indisputable fact. Terrestrial ecosystem is the important source and sink of greenhouse gases, and plays an extremely important role in global warming. Nitrogen deposition can affect the fluxes of greenhouse gases from terrestrial ecosystem. The responses of greenhouse gases emissions to nitrogen deposition in forest ecosystem, farmland ecosystem, grassland ecosystem and wetland ecosystem of typical terrestrial ecosystem are reviewed in this paper. As a result of the differences of ecosystem types, climate, vegetational community and soil N status, the effect of nitrogen deposition on main greenhouse gases flux emissions present in three aspects: suppression, promotion and non-significant in terrestrial ecosystem.

Abstract: Blood clam, Tegillarca granosa, habit in near-shore muddy sediments facing increasing danger of heavy metal contamination. In order to assess the acute toxicity of heavy metals on T. granosa, short term lethal concentration (LC₅₀) of copper (Cu), zinc (Zn), lead (Pb), and cadmium (Cd) were determined, symptoms of death and organic lesions were illustrated. With relative high LC₅₀ values obtained, T. granosa showed great heavy metal tolerance indicates adaptations to habitat environment. T. granosa died in acute Cd exposure showed specific death symptom with foot extended outside of the tightly closed shells. In this study, different metals led to different organic lesions. Dark red erosive and inflamed gills were observed for T. granosa exposed to acute Cu and Pb, respectively. Inflamed gonad and foot, and contracted mantle were observed for Cd and Zn exposure trials, respectively. The results of this study may provide knowledge to assist in heavy metal pollution bio-monitoring and quick diagnosis of massive death incidence.

Abstract: The interaction between sparfloxacin (SPFX) and human serum albumin (HSA) had been studied by spectroscopic and molecular modeling methods. The inner filter effect was eliminated to get accurate binding parameters. The site marker competition experiments revealed that SPFX binds to site I (subdomain IIA) of HSA and molecular docking was employed to further define the specific binding sites.

Abstract: Effects of the ethanol extracts prepared from Salix babylonica L. leaves on the fat deposit induced in mice by feeding a high-fat-diet for 9 wks were studied. Increase in body weight and parametrial adipose tissue weight containing 2,5 or 10g (extract) /kg food was suppressed as compared to that observed in mice fed the high-fat-diet alone. Futhermore, the enthanol extract inhibited the elevation of blood triacylglycerol in rats administered orally a lipid emulsion as compared to that in rats given the emulsion alone. Experiments are now undergoing to isolate other ingredients from the extract and test them for anti-obesity effects.

Abstract: This paper reports the phytoplankton investigation results which were collected in 15 observation stations and a day-night continuous observation station in the sea area near Sanmen Bay (29° 00'00 "~ 29° 10'26 "N, 121° 34'43" ~ 121° 47'06 "E) in spring(April), summer (July), autumn (October) of 2007 and winter (January) of 2008. After microscopic observation and identification, a total of 6 phyla, 56 genera, 146 species were identified in the sea near Sanmen Bay. The seasonal species change was spring (101)> autumn (96)> summer (96)> winter (85). The cell abundance of phytoplankton in the sea near Sanmen Bay was 0.72103～1.3106 cells /dm3, and the average cell abundance was 5.13104 cells /dm3. The mean cell abundance in winter was 1.27105cells/dm3 >4.72104cells/dm3 in autumn > 1.63104 cells/dm3 in spring > 2.51103cells/dm3 in summer. During the 24-hour continuous observation, in the day time, particularly in the afternoon, the photosynthesis was strong, and the cell abundance of phytoplankton was high; at night, especially in the latter half of the night or wee hours, the photosynthesis was weak, and the cell abundance of phytoplankton was low. The dominant species of phytoplankton in the Sanmen Bay was Skeletonema costatum. Ecological types of phytoplankton can be divided into three groups: (1) inner bay and coastal temperate group; (2) eurythermal and euryhaline group; (3) warm water off-shore group. Inner bay and coastal eurythermal and euryhaline group was the dominant group. The amounts of other groups were less. Totally 64 red-tide species were observed in the sea area near Sanmen Bay, of which, diatoms was predominant, 40 species; dinoflagellates was 19 species; Cyanophyta was 2 species; Euglena、Chrysophyceae and Protozoa was 1 specie respectively. The average cell abundance of the main red-tide organisms in the sea area near Sanmen Bay was 5.6102 cells/dm3～1.2105 cells/dm3. The dominant species composition and community structure of phytoplankton were mainly composed of diatoms, such as Skeletonema costatum, Ditylum brightwelli, Coscinodiscus jonesianus, Thalassiosira eccentrica, Leptocylindrus danicus, Chaetoceros lorenzianus; pyrrophyta, such as Ceratium fusus, Ceratium tripos, Ceratium furca etc.

Abstract: The essential oil from Michelia figo Spreng leaves was extracted by steam distillation. The antimicrobial activities of essential oil on bacteria and fungi were tested by plate counts and filter paper methods, and we also did the gas antisepticise experiment, analyzing the chemical constituents of essential oil by GC-MS. The results showed that: the antimicrobial effect of the essential oil from M. figo leaves on Escherichia coli G- , Staphylococcus aureus G+ and Bacillus sabtills were very good. The LC50 were: 0.64, 0.77, 0.62（μL•mL-1）, and the MIC were: 18.9, 20.1, 15.2（μL•mL-1）. But the essential oil had poor effect on Mucor racemosus, Aspergillus flavus and Rhizopus oryzae, the antimicrobial rates of them were lower than 50%. Gas antisepticise experiments showed it had good antimicrobial effects under the gas conditions. Twenty three compounds were separated and identified respectively from the essential oil, and the main antimicrobial compounds of the essential oil from M. figo leaves were analyzed in the experiment.

Abstract: The industrial effluents produced in petrochemical production contain kinds of pollutants and fluctuate wildly, also lead sewage plant to be impacted frequently. It is significant to develop a method that warms the effluents quality early, efficiently and accurately. As a result, it can make the biochemical devices run and manage smoothly. Based on the extreme sensitivity of Oxygen Uptake Rate (OUR) and Dehydrogenase Activity (DHA) to the abnormal effluents and toxicants, this study proposed a comprehensive assessment method of biodegradability and biotoxicity with Specific Oxygen Uptake Rate (SOUR) and Specific Dehydrogenase Activity (SDHA). And it also discussed the biodegradability and biotoxicity of the industrial effluents with different pH and toxicant by detecting OUR, SOUR and DHA. The results showed that, these three indexes were extremely sensitive and accurate to the effluents quality change. And the maximum concentrations of phenol, formaldehyde and carbinol that the microorganisms can allow in the industrial effluents were 350mg/L, 70mg/L and 170 mg/L. When the sewage plant was functioning normally, SOUR and SDHA fluctuations were 3.0~7.0 and 1.0~4.0 respectively. Therefore, they have important application value and prospect to early warming in the effluents quality.

Abstract: Abstract. Raising nitrogen utilization efficiency could not only cut the fertilizer costs, but also reduce the N loss and residual, which benefits a lot to agricultural production and environmental protection. In this experiment, the 15N tracing technique was employed in order to clear the accumulation and whereabouts of fertilizer N in flue-cured tobacco plants, besides, the tobaccos were treated by six different water-nitrogen modes, for the sake of finding out the best design with the highest nitrogen utilization efficiency. The results showed that more N application contributed to more fertilizer N accumulation, also increased the content of total N; Excess irrigation restrained the tobacco plants' absorption of fertilizer N, ultimately leading to the low utilization efficiency of nitrogen fertilizer; After apex pruning, the N offering ability of the soil was much stronger than that of nitrogen fertilizer, and the fertilizer N accounts a relatively small part for the total N in tobacco plants, the highest nitrogen utilization efficiency was 24.16%, recorded in the design of 800mm irrigation amount and 6g/plant pure N application(T2), Meanwhile, the agronomic characters and crop yield was observed, tobaccos in T2 design performed better than the average level of field-cultivated tobaccos, the conclusions could be obtained that T2 design was preferable, which achieved the highest nitrogen utilization efficiency when ensured the normal growth and good harvest of flue-cured tobacco.

Abstract: The interest in the effect of firefighting foams on the environment has increased. Biodegradation is an important influencing factor when considering the environmental effect of firefighting foams. In this paper, an evaluation system based on CO₂ evolution method was established to evaluate the biodegradation of Class A foams, and the biodegradation of three kinds of Class A foams were compared. The results show that both aniline and sodium benzoate can be employed as reference compounds using CO₂ evolution method. Three kinds of Class A foams had biodegradation rates of 88.64%, 85.27% and 88.62% respectively after 28 days, which means they are easily biodegradable. Data from different test methods could not be compared directly.