[Distribution Characteristics and Potential Ecological Hazards Assessment of Soil Heavy Metals in Typical Soil Profiles in Southeast Suburb of Beijing].

To investigate the distribution characteristics and the potential ecology risk of different types of heavy metals, soil samples were collected from various stratigraphic sections in the southeastern suburb of Beijing, where soil heavy metal (Cu, Pb, Cr, As) contents were measured and analyzed using multivariate statistical analysis and the potential ecological risk index method. The results showed that the concentrations of the four heavy metals followed the order of Cr > Cu > As > Pb with variable coefficients ranging from 59.60% to 159.

[Compositions and residual properties of petroleum hydrocarbon in contaminated soil of the oilfields].

The aims of this study were to determine the compositions and residual properties of petroleum hydrocarbon in soil, as well as to identify the source and weathering degree of the pollution. A total of 5 producing wells in Gudao and Hekou oil producing region of Shengli oilfields were analyzed. More than 50 individual target compounds including straight-and branched-chain alkanes( n-alkanes, pristine and phytane) and polycyclic aromatic hydrocarbons (PAHs) in soil samples and crude oil were determined by gas chromatography-mass spectrometry (GC-MS).

[Microbial community structure and distribution characteristics in oil contaminated soil].

Molecular biology methods such as PCR-DGGE combined with phylogenetic analysis were used for the soil microbial community structure and distribution profiling. Relationship of microbial community structure and distribution differed in a typical oil contaminated field was studied. Results showed that soil oil content was the main factor to the difference of microbial community structure similarity.

[Effect of permeabilization on sulfate reduction activity of Desulfovibrio vulgaris Hildenborough cells in the presence of different electron donors].

The Desulfovibrio vulgaris Hildenborough (DvH) cells permeabilized with ethanol were used as biocatalysts to enhance hydrogenotrophic sulfate conversion. The effect of permeabilization extent of DvH cells on sulfate reduction was studied in the presence of different electron donors. When hydrogen was used as an electron donor, the highest level of sulfate reduction activity attained in cells treated with 10% ethanol (V/V), followed by 15% -ethanol treated cells.

[Compositions and diagnostic ratios of heavily degraded crude oil residues in contaminated soil in oilfields].

The aims of this study were to determine the rate of degradation of crude oil in soil, to reveal the fingerprints of residual oil after long-term biodegradation, and to screen parameters for evaluation of the biodegradability residual oil. A total of 18 contaminated soil samples containing heavily degraded crude oil residuals from Daqing, Shengli and Baise oilfields were analyzed. More than 100 individual target compounds including straight-and branched-chain alkanes (n-alkanes, pristane and phytane), polycyclic aromatic hydrocarbons (PAHs), terpanes, steranes and triaromatic steranes (TAS) in residual oil were determined by gas chromatography-mass spectrometry (GC-MS).

[Effects of aerobic exercise on exercise tolerance in patients with chronic heart failure].

Objective: To explore the effects of aerobic exercise on exercise tolerance in patients with chronic heart failure (CHF).

Methods: A total of 50 CHF patients with left ventricular ejection fraction (LVEF) < 49% by echocardiography were enrolled. And they were randomly divided into exercise group (n = 25) and non-exercise group (n = 25).

[The effects of aerobic exercise on cardiac output during exercise in patients with chronic heart failure].

Objective: To observe the effects of aerobic exercise on cardiac output during exercise in patients with chronic heart failure (CHF).

Methods: A total of 50 CHF patients (echocardiography measured left ventricular ejection fraction < 0.49) were enrolled in the study and randomly divided into aerobic exercise group (n = 25) and control group (n = 25).

[Groundwater pollution risk mapping method].

Based on methods for groundwater vulnerability assessment not involving in contamination source elements, and lack of the systemic and effective techniques and parameter system on groundwater pollution risk mapping in present, through analyzing the structure of groundwater system and characteristics of contaminant sources, and coupling groundwater intrinsic vulnerability with contaminant sources, the integrated multi-index models were developed to evaluate the risk sources of groundwater contaminant and form the groundwater pollution risk mapping in this paper. The models had been used to a large-scale karst groundwater source of northern China as a case study. The results indicated that vulnerability assessment overlaid risk pollution sources of groundwater could effectively confirm the high risk regions of groundwater pollution, and the methods might provide necessary support for the supervision of groundwater pollution.

[Performance of a combined bio-chemical sulfidogenic system and microbial characteristics in the presence of H2].

To study and evaluate the performance of the continuously-operated autohydrogenotrophic sulfate reduction technique enhanced with electrochemical method and to improve the sulfate removal efficiency, a combined bio-electrical sulfidogenic system was developed with a three-dimensional bio-cathode. Sulfate reduction rate was elevated markedly owing to H2 mass transfer enhancement, biomass augmentation and electrical field stimulation. Indeed, when a current of 0.

[Bio-electrochemical effect on hydrogenotrophic sulfate reduction stimulated by electrical field in the presence of H2 under atmospheric pressure].

Microbial sulfate reduction rate is limited with H2 as electron donor. In order to improve hydrogenotrophic sulfate reduction under normal atmospheric H2 pressure, a bio-electrochemical system with direct current was designed and performed in this study. Results indicates that sulfate reduction rate (SRR) increases with the augment of current intensity under lower current intensity (I < or = 1.

[Microbial community constitute and phylogenetic analysis on oil polluted soils in oilfields of China].

The microbial communities in oil polluted soils from oilfields of China were analyzed using a modern molecular biological approach. The crude total DNA from soils were directly extracted, 16S rDNA fraction were amplified by PCR, the bands were separated using denaturing gradient gel electrophoresis (DGGE), and some of the typical bands were sequenced and compared with the records of NCBI to classify the germs. Comparison of the DNA extraction indicated that the yields were 1.

[Performance of slow-release organic carbon-source (SOC) materials for in-situ biological denitrification in groundwater].

As lack of electron donor (carbon source) is a key problem of in-situ denitrification in groundwater, slow-release organic carbon-source (SOC) materials were produced as appropriate electron donor in denitrification PRB. GPVAS and GEPVAS series were manufactured by blending starch and PVA together, with alpha-amylase as the additive, and their performance was detected through SEM and static batch experiments. The results showed that PVA formed the framework filling with starch molecule, and the carbon releasing process followed the law of second order kinetics.

Sensitivity of key factors and uncertainties in health risk assessment of benzene pollutant.

Predicting long-term potential human health risks from contaminants in the multimedia environment requires the use of models. However, there is uncertainty associated with these predictions of many parameters which can be represented by ranges or probability distributions rather than single value. Based on a case study with information from an actual site contaminated with benzene, this study describes the application of MMSOILS model to predict health risk and distributions of those predictions generated using Monte Carlo techniques.

[Removal of oil in the lake water in Daqing area using subsurface constructed wetland].

Based on the water quality and climate of the oil contaminated lake in Daqing area, four simulated subsurface wetland systems were constructed in the field to study their removal effect of oil in lake water, including the gravel bed, the gravel-reed bed, the slag-reed bed and the slag bed. The research lasted about 360 d, including five periods: the start up period, the microorganism adding period, the slow-releasing carbon sources adding period, the low temperature period and the normal operation period. During the study, oil removal efficiency of the four units are 24.

[Uncertainty analysis of health risk assessment caused by benzene contamination in a contaminated site].

Lots of uncertainties lie in the procedure of environmental risk assessment (ERA) and how to analyze them exactly is studied comprehensively. Based on the investigation of petroleum contamination in a contaminated site, the representative benzene contaminant in soil was selected to analyze uncertainty of environmental risk resulting from drinking and inhalation exposure routes, using the Monte-Carlo simulations. According to the analysis results, the total health risk average value caused by benzene contamination from the alkene factory is 1.

[Physical and chemical effects and plant growth suitability of substrates in subsurface flow wetland].

Substrate, which not only takes part in the pollutant-removing, but influences the plant growth, plays an important role in subsurface flow wetland. With X-ray fluorescence measurement and X-ray diffractometer, the elements and minerals in zeolite and shale were confirmed, and the removal mechanics of nitrogen, phosphate and hydrogen ion in substrates were explained respectively. The investigation show that the zeolite has abounded with micropores and mesopores, while the shale has only mesopores, which causes the NH4+ -N adsorption capability of the shale is less than zeolite.

[Relationships between loading rates and nitrogen removal effectiveness in subsurface constructed wetlands].

About forty kinds of nitrogen loading removal rate were studied in field in 15 months, inflow and outflow loading rules of reeds/Zizania caduciflora/mixing and no-plant bed were discussed in different inflow loading. The four kinds SFS inflow loading changed from 400 mg x (m2 x d)(-1) to 8 000 mg x (m2d)(-1), while outflow loading is less than 7,000 mg (m2 d)(-1). Results show that outflow loading increase with the increase of inflow loading, linear relation is obvious.

[Effects of plants on nitrogen/phosphorus removal in subsurface constructed wetlands].

Effects of plants on nitrogen/phosphorus removal was studied in pilot-scale in subsurface constructed wetland, the main contents included nutrient uptake, effects of harvesting and roots on hydraulic condition. The result show that the amounts of nitrogen and phosphorous removed by plant harvesting is about 5% of the total removed nutrients in SFS wetlands. The best harvesting periods is between 9-10 month every year.

[Effects of acid soils on the biodegradation of hydrocarbons].

Biodegradation efficiency of hydrocarbons and melioration of micro-ecosystem conditions in acid soils should be seriously concerned due to either occurrence of acid polluted soils or acidification during bioremediation process. The influence of acid situation on degrading microbes and the biodegradation rate were figured out by monitoring variations of biomass, microbial activities and petroleum contents with time in acid and alkaline polluted soils in laboratory. Injecting degrading microbes and meliorating micro-ecosystem conditions of acid soils were conducted.

[The relationship between abiotic factors and microbial activities of microbial eco-system in contaminated soil with petroleum hydrocarbons].

By means of the biostimulation and bioaugmentation in the micro-ecological environment of contaminated soil with petrochemical hydrocarbons, the biodegradation rates and mode of the contaminants were significantly improved. Based on the investigations carried out in some oilfields and petrochemical industrial area of Northern China, the relationship between the abiotic factors such as nutrient, pH, contaminants, water content, alkalinity, etc., and microbial activities was interpreted and identified in this paper.

Production of biosurfactant and its role in the biodegradation of oil hydrocarbons.

Based on indigenous bacteria from the oil-contaminated site of Dawu water source area in Zibo city of China, the production of biosurfactant and its role in the biodegradation of oil hydrocarbons have been investigated. Batch experiments were performed with paraffin as the sole substrate under temperature of 30 degrees C and pH of 7. Two high-effective species of bacteria (Z1 and Z2) were isolated.

Volatile fatty acids as electron donors for the reductive dechlorination of chloroethenes.

Uses of a mixture of six volatile fatty acids (VFAs) including acetic, propionic, butyric, isobutyric, valeric and isovaleric acids as electron donors for the reductive dechlorination of chloroethenes have been investigated by both microcosm and column studies. The fates of tetrachloroethene (PCE), cis-dichloroethene (cis-DCE) and vinyl chloride (VC) in the presence of VFAs and in the absence of VFAs were respectively documented. The results showed that VFAs stimulated complete reductive dechlorination of chloroethenes, either as direct substrates for the dechlorinating bacteria or via H2 formed during VFAs-degradation.