Nature Environment and Pollution Technology

Yali Yu ¹, Xunchi Pu ¹, Ran Li ¹, Hong Jiang ², Yong Li ¹

Affiliations
1 State Key Laboratory of Hydraulics & Mountain River Engineering Sichuan University, Chengdu 610065, CN
2 Chengdu Engineering Corporation Limited Power China, Chengdu 610072, CN

Abstract

Water landscape quality is an important part of environmental quality. However, in the environment impact assessment, there is no method at present that can quantitatively assess the colour changes of the water landscape affected by sediments. This paper presents a conception of organoleptic chromaticity according to the engineering requirement. Water organoleptic chromaticity is defined as a water chromaticity which is caused by both soluble substances and insoluble substances and observed directly by naked eyes. Using the spectrophotometry, it was found that the maximum absorption peak of coloured-turbid water occurred at 350nm which is defined as the characteristic wavelength of water organoleptic chromaticity. Based on the standard turbidity and chromaticity solutions, the metric system of organoleptic chromaticity was established. The absorbance of water with different turbidity and chromaticity showed that it is linear with the organoleptic chromaticity. Measuring the organoleptic chromaticity of different sandy waters, the results demonstrated that the metric system of organoleptic chromaticity could apply to the quantitative assessment of landscape quality for engineering sandy water in practical engineering.

Keywords

Organoleptic Chromaticity, Sediment Water Landscape, Spectrophotometry.

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Jin-lan Niu ¹, Ran Li ¹, Xia Shen ¹, Le-le Wang ¹

Affiliations
1 State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu 610065, CN

Abstract

Spill discharge and abrupt water temperature rising may result in total dissolved gas (TDG) supersaturation, which can lead to gas bubble disease (GBD) and even cause mortality of fish. Studies on the mitigation measures about how to promote the dissipation process of supersaturated TDG are essential for the protection of fishes. In this paper, the experimental research about the promotion of supersaturated TDG dissipation by using activated carbon was conducted in static water and stir-induced turbulent water respectively. Supersaturated TDG dissipation processes with different content of activated carbon have been monitored and the dissipation coefficients of supersaturated TDG under various conditions were obtained. The results indicate that the activated carbon can increase the dissipation speed of TDG obviously. The higher the activated carbon content is, the greater the dissipation coefficient is. It can be concluded that the TDG supersaturation problem can be mitigated by introducing activated carbon and enhancing water turbulence when supersaturated TDG occurs in the fish ponds or fish proliferation stations. This study can provide scientific data for the exploration of mitigation measures of supersaturated TDG, which is fundamental for the protection of fishes.

Keywords

Activated Carbon, Total Dissolved Gas, Supersaturation, Dissipation.

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Hui-Xia Yang ¹, Ran Li ², Juan Wei ³

Affiliations
1 College of Civil Engineering, Guizhou University, Guiyang 550025, CN
2 State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu 610065, CN
3 Sichuan Port and Channel Development Co. Ltd, Chengdu 610072, CN

Abstract

High concentration of total dissolved gas (TDG) in the tailrace of high dam may induce gas bubble disease to the fish for lethal effect. Thus, the distribution of the TDG concentration in the plunge pool and immediately in the downstream of dam becomes critical. In order to proves to be effective and convenient, but the determination of the model parameter relies on field observed data and the calibration of the parameter is time-consuming. In this paper, the predictive relationship of the parameter in the TDG transport equation with a source term is developed. Observed field data from six spillways in China were used to fit the source parameter that the predictive relationship needed. The inclusion in the predictive relationship will allow for the estimation of the source parameter representing the mass transfer between bubble/water interfaces and may give an insight into the mitigation of high TDG concentration downstream of spillways.

Keywords

Total Dissolved Gas, Dissipation Coefficient, Bubble Distribution, Mass Transfer, Parameter Analysis.

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