Nature Environment and Pollution Technology

Liqin Zhu ¹, Cuiling Jiang ², Youheng Wang ², Yanmei Peng ², Peng Zhang ²

Affiliations
1 Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Nanjing, 210098, CN
2 College of Hydrology and Water Resources, Hohai University, Nanjing 210098, CN

Abstract

Lihe River as an important water conveyance canal of diversion project from Luanhe River to Tianjin should convey 40-50 m³/s water in each spring and autumn. With the variation of water discharge, the sediments with poor viscosity and great suspension capability were very prone to re-suspension and pollutants release easily. In order to study the effects of pollutants release in sediments on river during water diversion period and set out proper protection scheme to prevent the second pollution, experiments were done to make clear the levels of accumulation and release mechanism of pollutants in sediments. First, compared with those in Haihe River, Wulihu Lake and Xuanwuhu Lake, the average content of organic matters of sediments in Lihe River was 0.21%, lower obviously, TP with the average value of 5.18 mg/kg was much higher, while TN reaching 2.99 mg/kg, a little higher than others. Second, water diversion indeed made pollutants in sediments release quickly and threaten water quality seriously. TN was the main pollutant, a high level in both river and sediments, which kept releasing with the maximum release amount of 9.16 g/m² and intensity 4.2 g/m²/d and had a great negative influence. TP and Fe with the maximum release amounts were 0.248 g/m² and 1.7 g/m² with maximum release intensities of 0.248 g/m²/d and 1.7 g/m²/d respectively. They released fast and deposited also fast, and were the potential pollutants and the release amounts could not be neglected during the initial water diversion period.

Keywords

Lihe River, Water Conveyance Canal, Sediments, Pollutants.

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Yeqiu Wu ¹, Angui Li ¹, Jiangyan Ma ¹, Ran Gao ¹, Jiang Hu ¹, Bin Xiao ², Peng Zhang ²

Affiliations
1 School of Environmental and Municipal Engineering, Xi’an University of Architecture and Technology, Xi’an, 710 055, CN
2 China Hydropower Engineering Consulting Group Co., Xi’an, 710 065, CN

Abstract

The use of computational fluid dynamics (CFD) is becoming more common and reliable as a tool for kinds of buildings fire safety design, but it is not easy to be validated. In this paper, Fire Dynamics Simulator v5.0 is used to investigate the spill plume and the resultant natural filling in the underground transport passage of main transformer of a hydropower station due to the adjacent main transformer hall fire. Ceiling jet temperature decay along the transport passage and smoke layer interface height are simulated. Series of scale model experiments are carried out using pool fires placed at the centre of the main transformer hall. The data obtained from these experiments are later used in a validation study of the FDS simulated results. The FDS simulated results are also compared with the expressions proposed in the literature. The results show good agreement between experimental and numerical predictions. And through suitable adjustment of the constants of the exponential equation, good agreements are also found between the predicted data and calculated results.

Keywords

Smoke, Underground Passage, Reduced-Scale Experiments, FDS, Spill Plume.

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