Advanced Materials Research Vols. 807-809

Abstract: Two expressway sections including the south section of the beltway in Xian and the start section of the Xi'an-Lantian expressway were selected in this study. By monitoring the acoustic noise level at different frequencies and vehicle speeds, a frequency related source intensity prediction model of the traffic acoustic noise was developed. Experimental results show that the spectrum distribution varies greatly among different kind of vehicles. The noise source intensity produced by large vehicles mainly distribute in low-frequency area. Different from large vehicles, medium vehicles mainly produce medium or high frequency noise, especially when the vehicle's speed is above 60 km/h. When the vehicle's speed is below 60 km/h, the acoustic noise intensity produced by the medium vehicles is relatively weak. The accuracy of the source intensity prediction model is further proved by comparing the predicted data, determined data, and the data obtained in the literature under similar experimental conditions.

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 kinds of relative humidity. The three kinds of relative humidity were 70%, 80% and 90% and it was analyzed that the plume character under these three kinds of relative humidity. Results showed that the plume length, plume height and plume radius will present different change trend when relative humidity changed. Additionally, the plume dispersion character in different seasons presented obviously variations and the different wind direction also play important role in prediction of cooling tower plume dispersion.

Abstract: Expressway has a deep, irreversible influence on the ecological environment. Through assessment and evaluation on several expressways in the territory of China, this paper shows that the main source of air pollution caused by expressway is motor vehicle exhaust and dominated by lead pollution; noise pollution caused by expressway is mainly traffic pollution along the road during operation. However, the noise pollution is seriously overweight; the construction and operation of expressway has an impact on water environment, water and soil conservation and living environment for animals and plants. At the same time, the closure of expressway operation has impeditive functions to residents living along the road.

Abstract: Bioventing is an in situ forced oxidative soil remediation technology which combined soil vapor extraction with biodegradation. It has broad application prospects of soil contamination caused by underground storage tank leakage. Orthogonal experiment as a high efficiency, rapid and economical experimental design method has been widely used in many research. In order to enhance bioventing and shorten the cycle of pollution control,it is necessary to study the mechanism of the interaction among the different factors to quantify the interaction and accelerate the degradation rate. In this study, five factors (initial diesel concentration, venting mode, pore volume number during soil venting, soil moisture content and the ratio of carbon, nitrogen and phosphate) which influence bioventing was chosen to conduct orthogonal experiment of the remediation of diesel contaminated soil by enhancing bioventing. The results show that: 1)Initial diesel concentration and soil moisture content have main effects on the remediation of diesel contaminated soil by bioventing, then the ratio of carbon, nitrogen and phosphate and pore volume number during soil venting. Venting mode has the weakest effect. 2)When 40mg oil/g soil of diesel concentration, air injecting from the bottom of column, 4 v_k·d^-1 of the pore volume number during soil venting, 100:20:1 of the ratio of carbon, nitrogen and phosphate and soil water content for 20% of the maximum of soil water holding capacity, that would reach a larger removal rate.

Abstract: Concentrations characteristics of six heavy metals (Cu, Cr, Cd, Mn, Zn, Pb) in 7 soil sample from different loactions of Quercus aquifolioides frest were investigated. The concentrations and potential ecological risk of heavy metals in the soils was assessed when compared to the background values of heavy metals in three different soils, i.e. total, yellow-brown and yellow soils in China. The average concentration of heavy metals in Quercus aquifolioides soils was in the order Mn>Cr>Zn>Cu>Pb>Cd, while the average concentrations of all examined heavy metals were lower than those in the Environmental Quality Standard for Soil (grade I) in China. In all examined heavy metals, Mn (474.7mg/kg) had the highest average concentration and Cd (0.039mg/kg) had the lowest one, with variation coefficients ranged 33-87% for the six heavy metals. Correlation analyses showed that the three heavy metals (Cu, Mn and Pb) probably came from the same resources, and so did of Cr and Pb. Comprehensive pollution indices (0.57-1.71) indicated the Quercus aquifolioides soils were slightly polluted by the six heavy metals and ecological risk indices (8.42-51.0) also show the situation of heavy metals was in the slight level in the soils. Among the examined heavy metals, Cu and Cr were two main heavy metals who making pollution and potential ecological risk to the soils.

Abstract: Eco-hydrological processes in the earth surface system reveal the ecological pattern of hydrological and ecological processes change mechanism, and reflect the development and evolution processes of the earth surface system. The ecological hydrological processes were simulated in the study using SWAT (Soil and Water Assessment Tool) model, which is developed by the United States Department of Agriculture (USDA) Agricultural Research Service (ARS). First, the space and attribute databases model required were constructed. Secondly, based on digital elevation model (DEM) the hydrological parameters were calculated, including determine the grid cell flow, calculate the unit catchment area, divided watershed boundaries, generate river nets, divide sub-basin. Based on the parameter sensitivity analysis, the eco-hydrological process simulation was completed through the model calibration and validation. Then the potential evapotranspiration, actual evapotranspiration, soil water, water yield and other eco-hydrological parameters were selected for analysis. The results show that trends of potential evapotranspiration and actual evapotranspiration in study region are consistent, and the values are almost the same. Monthly soil water is between 150mm and 200mm, and strict correspondence to precipitation. It is a certain correlation between soil water content and evapotranspiration. When soil water content is low, evapotranspiration is small, but there is about two months of the time lag. The characteristics of ecological and hydrological processes in study region show typical southeast coast in China.

Abstract: Wet digestion method had been used in river deposit of BZ profile. At the same time, Mn, Cu, Ba, Ni, Pb, Zn, Rb, V, Sr and Zr in river deposit were determined by ICP-OES. The results show that the relative standard deviations are all below 0.39%, while the recovery of standard addition is 94.3%~117.1%. The method is proved to have good precision and accuracy, and to be simple and rapid. And the measured data provide basis for paleoflood study in this area.

Abstract: To study the impact of atmospheric Cd exerts on the soil accumulated of Qingdao urban area, atmospheric dust and soil samples are collected and analyzed. Based on these tested samples, this paper firstly analyzed the geochemistry characters of Cd in atmospheric dusts and soils using the statistic analysis method. Then according to the time accumulation model about the influence of Cd exerts on soil, this paper predicates the influence that atmospheric Cd in dust exerts on soil 20 years later. Analysis results show that atmospheric Cd has great influence on the accumulated soil. For example, it can cause the deterioration of soils quality. Therefore, to prevent soil from Cd pollution, the detection and control of atmospheric Cd should be strengthen.

Abstract: This thesis has provided a detailed survey of the basic situation of air pollution sources (point sources, non-point sources and line sources) in Chengdu urban agglomeration and calculated the pollutant emissions for each type of pollution sources by using the pollution source monitoring data (on-line monitoring and routine monitoring) or emission factor method. A temporal allocation has been carried out for the emissions of each type of sources (point sources, non-point sources and line sources) according to the production characteristics of the industrial enterprises which discharge air pollutants, the working and living law of human being and driving rules of vehicles. As for the spatial allocation of pollution sources, enterprises with confirmed location have been located by their latitude and longitude. For pollution sources whose location is unknown, their spatial allocation has been carried out and a detailed emission inventory of the pollution sources has been compiled on the basis of the population ratio of each grid and GDP output ratio, which provides basis data for the air quality stimulation and policy-making for prevention and control of air pollution of urban agglomeration.

Abstract: Using artificial light source to supplement light for submerged plants in water where the illumination is insufficient can promote the growth and improve the purification ability of submerged plants. The attenuation rule of underwater irradiation is the key to design and place the lamps. High-precision underwater spectrograph was adopted to study the underwater light spectrum and attenuation rule of underwater irradiation. The results showed that the attenuation rate of total irradiation (E) with depth (h) and turbidity (t) in algae water is the most remarkable; the relationships of E with h and t in different water were E₁(t,h)=E₀e^-K(t)h=E₀e^{-(0.1345t+0.1206)h}(muddy water), E₂(t,h)=E₀e^-K(t)h=E₀e^{-(0.203t+0.4684)h}(algae water) and E₃(t,h)=E₀e^-K(t)h=E₀e^{-(0.1708t+0.2279)h}(mixed water). By these relationships, the position of artificial light could be calculated.