水质恢复能力评价方法及其在黄河流域的应用

Evaluation Method of Water Quality Recoverability and Application to the Yellow River

在探讨水体水质恢复途径的基础上,建立了水质恢复能力评价标准和方法。根据黄河干流1998年的纳污情况及河水中三类主要污染物(BOD、氨氮和挥发酚) 的浓度对黄河干流的水质恢复能力进行了评价,发现对于单位河长,除潼关—三门峡河段水质恢复能力属中等以外,其余河段水质恢复能力均较弱。物理稀释作用对水相中污染物浓度降低的贡献相对较小;各河段的水质恢复能力与泥沙含量呈显著正相关,与水温呈一定程度的正相关。黄河干流这种较差的水质恢复能力表明黄河干流的环境功能较弱,且现有的污染物排放已经超过了其水质恢复的能力,从而致使水质恶化,影响水资源的可持续利用。

The evaluation of water quality recoverability is the basis for the realization of sustainable usage of water resources. In this research project, the criteria and method for the assessment of water quality recoverability have been set up based on the analyses of mechanism of water quality recovery. Water quality recoverability in the mainstream of the Yellow River has been evaluated through the analyses of pollutant discharge and the three main pollutant concentrations including BOD, NH 4+ -N and volatile phenol in river water. The results show that the water quality recoverability is weak in the mainstream of the Yellow River except that it is moderate in the section of Tongguan-Sanmenxia. The contribution of physical dilution to the water quality recoverability is relatively small; and water quality recoverability is remarkably and positively correlated to the silt content in river water and positively correlated to water temperature to some extent. The weak recoverability of water quality in the mainstream of the Yellow River manifests that the environmental function is also weak. Yet the pollutant discharge to the mainstream of the Yellow River is beyond the water quality recoverability, which leads to the deterioration of water quality and exerts negative effects on sustainable utilization of water resources.