动态水流条件下河流底泥污染物(COD_(Cr))释放研究

为了研究不同水深、流速等水动力条件对底泥中污染物释放强度的影响,以苏州河底泥为例,通过水槽试验,分析了动态水流条件下河流底泥中污染物释放及其对上覆水体水质的影响.结果表明,CODCr释放率随时间的增大而增大,但CODCr释放强度随时间的增大而减小.底泥中污染物释放率与水深和流速有关,在相同水深的条件下,底泥的释放率随着流速的增加而增大;在相同流速的条件下,底泥的释放率随着水深的增大而减小.在水深10cm、流速0.10m.s-1的动态水流条件下,底泥向上覆水体释放CODCr的释放强度与时间的关系为:C=1.06C0e-0.06t.

Contaminant (CODCr) release from river bottom sediments under flow conditions

Comprehensive treatment and pollution prevention of pollutants in bottom sediments is an important problem in urban river rehabilitation projects. In this paper, the bottom sediment of Suzhou creek was selected as a test sample and the effect of sediment contaminants on upper water body quality was analyzed by means of water flume testing under different hydrodynamic conditions. The results show that the water depth and the flow velocity both contribute to the release rate of sediment contaminants. For a given depth, the release rate increases with velocity, while for a given water flow velocity the amount of bottom pollution released decreases with the water depth. Over time, the CODCr release rate slowed while the CODCr release intensity grew. The variation of the release intensity with time under the test conditions was obtained.