Applied Mechanics and Materials Vols. 316-317

Abstract: The SACTI model (Seasonal Annual Cooling Tower Impact) as the environmental impact assessment of cooling tower was applied in this paper, which was used to simulate the plume characters under different cooling tower heights. The results showed that the plume length, plume height and plume radius presented noticeable differences with variances of different distances and wind directions under different cooling tower heights. The comparisons of differences of plume characters indicated that the relative change of plume length frequency displayed obvious decreased trend with increased distance when distance was greater than 500m, and that of plume height frequency appeared parabolic curve with increased distance. The relative change of plume radius frequency expressed totally descended trend.

Abstract: In this experiment, 25 oil degrading bacteria strains were isolated from the beach near Dalian Bay. The top 4 high efficient oil-degrading bacteria（SQ、SY 、SW、SC） were selected to be studied. Using Physiological and biochemical identification, electron microscopy, and 16S rDNA sequence analysis, strain SQ was identified as Advenella kashmirensis，SY was identified as Achromobacter xylosoxidans, SW was identified as Acinetobacter venetianus，SC was identified as Alcaligenes xylosoxidans subsp.xylosoxidans. For the first time this experiment provided reference to application and degradation characteristics of Advenella kashmirensis in crude oil treatment. These four marine oil degrading bacteria were selected to form bacterial consortium. The most efficient mixed strains were constructed by using these four strains with proportional combination. The oil removal ratio of the optimal mixed strains increased to 70.33%, nearly 25% higher than the highest degradation rate of single bacterium, showing significant synergism in the bacterial consortium. Advenella kashmirensis enhanced oil degradation obviously, playing a crucial role in the bacterial consortium.

Abstract: “5.12 Wenchuan earthquake”triggered floods, landslide, collapse and secondary geological disaster, trigger a new soil and water loss, having the significant influence to the local river water quality.This article through the statistical analysis of minjiang river and jiangyou wenchuan, beichuan station 2006 ~ 2011 water conditions material, discussing the before and after the earthquake disaster areas of river water quality change characteristics. The results showed From ammonia nitrogen source analysis, urban sewage and industrial waste water, agricultural non-point source pollution and earthquake that triggered the new soil and water loss is the main pollution source. Based on the hydrological site total hardness concentration prediction, we can find wenchuan earthquake disaster area total hardness concentration significantly increase trend.

Abstract: In recent years, water pollution is increasing, especially organic pollution. The chemical oxygen demand (COD) is one of the most important evaluation index. Compared with the traditional chemical analysis method of COD, the method of spectrum analysis of organic pollutant concentration in water quality detection is fast, no chemical reagent and simple operation etc, and it is a kind of green testing technology. The current spectrum method of water quality analysis is usually based on single wavelength or the feature band extracted. It is lack of methods with the full spectrum scan. Based on water quality research,we choose the spectral analysis of COD as the objective. Combining the ultraviolet absorption spectrum with the conventional five physical parameters as the absorbance in the last wave band, we use the iterative predictor partial least squares algorithm to realize the rapid detection of water quality COD.

Abstract: As a kind of typical EDCs, bisphenol A (BPA) has biological toxicity and estrogen effect. Previous removal methods have some shortcomings, such as adsorbent is difficult to retrieve and degradation efficiency is not good enough. In order to overcome these problems, some new methods are proposed. Most of them combine the new technologies and traditional methods to achieve the purpose of cooperation. Results show these methods have higher removal efficiency and overcome some shortcomings of the traditional methods. Although there are still some problems, these new methods propose a new direction for the future.

Abstract: The paper is an overview of some new issues that are connected with the removal of N-Nitrosodimethylamine (NDMA) by some water technology. NDMA is the most frequently detected member of extremely carcinogens, the N-nitrosamines. In this paper, the recent new methods for removing NDMA are introduced and proposed the future direction of the research about the removal of NDMA.

Abstract: So far, the study on diversity of microbial community which produces flocculating substances is relatively few. In this paper, soil, activated sludge and wastewater samples are collected from 21 different places, and then are cultivated in 5 different media. 5 different colony groups form large amounts of slime externally, which having high level of flocculation activities. Biolog is used to analysis the functional diversity of microbial communities.The microbial community BF-BCT having highest flocculating capability. The AWCD analysis results shows that the micro be in the BF-BCT utilized more carbons compared with the other six colony groups. In addition, the diversity analysis has similar conclusions with PCA analysis.

Abstract: The method of the heterotrophic denitrification remediation of nitrate-polluted groundwater involves the study of organic carbon sources as electron donor. The aim of the present study was to evaluate wheat straw for its ability to enhance denitrification in column experiments. The inlet concentration was 50.0 mgNO₃^--N/L and the column operated at the flow rate of 2.0 ml/min. The result showed that in the presence of wheat straw, highly reducing conditions were generated and complete removal of nitrate (>95%) was achieved, with less accumulation of nitrite. Consequently, wheat straw is an attractive carbon source for groundwater denitrification.

Abstract: In order to get an accurate test method of trace phosphorous in drinking water, different test methods of phosphorus were researched. Drew standard curves of these methods, Calculated correlation coefficient of these standard curves for comparison. The result shows that the improved PMA-Malachite Green spectrophotometry was more accurate in the test of trace phosphorus, by using the cuvette with 1cm light path, the correlation coefficient of it's standard curve can reach 0.9995. The improved method is suitable for measuring trace phosphorus in drinking water.

Abstract: Groundwater in fractured media plays an important role in drinking water supply, and the understanding of its principle mechanisms is essential for securing the groundwater exploring and utilization. In this paper, a novel conceptual fracture model was presented on the basis of the reality of channeling flow in natural fractures and laboratory experiments were conducted for the purpose of getting a better understanding of the step-like breakthrough curve (BTC). Experimental results were fitted with convective dispersive equation (CDE) and compared with those of the finite element method (FEM) models. Results showed that the traditional one-dimensional CDE was invalid in the fitting of a step-like BTC and needed to be improved.