Despite the extensive attention paid to the transport of heavy metals in sludge landfills, the processes of transporting these pollutants from a landfill to the underground environment are quite complicated and subject to significant uncertainty. In this study, the transport of typical heavy metal pollutants in a sludge landfill through saturated and unsaturated soil zones during rainfall was investigated via numerical modeling. The objectives of the study are to evaluate the heavy metal pollution risk from a sludge landfill under rainfall infiltration conditions and to propose several management suggestions. The results indicate that, during rainfall, heavy metal concentrations at the top of the unsaturated sludge layer decrease rapidly, but they decrease more gradually at the bottom of the layer. The maximum concentration appears in vertical distribution and decreases gradually through the saturated zone. Nickel is the first heavy metal pollutant to break through the low-permeability natural silt barrier. The transport parameters not only influence the simulated time for heavy metal pollutants to break through the silt layer and cause underground environmental pollution but also affect the extent to which the heavy metal pollutants in pore water exceed the guidelines. On the basis of these results, for dredged sludge with heavy metal concentrations significantly exceeding the standard, the concentration of heavy metals in pore water should be reduced before the sludge is landfilled, and a covering layer should be established on the sludge surface to control rainfall infiltration.

中文翻译：

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污泥填埋场重金属污染风险的数值评估和管理建议-以深圳福永填埋场为例

尽管人们对污泥填埋场中重金属的运输给予了广泛关注，但将这些污染物从填埋场运输到地下环境的过程却相当复杂，并且存在很大的不确定性。在这项研究中，通过数值模拟研究了污泥填埋场中典型的重金属污染物在降雨过程中通过饱和和非饱和土壤区域的迁移。该研究的目的是评估降雨渗入条件下污泥填埋场的重金属污染风险，并提出一些管理建议。结果表明，在降雨过程中，不饱和污泥层顶部的重金属浓度迅速下降，但在污泥层底部的重金属浓度下降更为缓慢。最大浓度以垂直分布出现，并在饱和区逐渐降低。镍是第一个突破低渗透性天然淤泥屏障的重金属污染物。输运参数不仅影响模拟的重金属污染物冲破淤泥层并造成地下环境污染的时间，而且还影响孔隙水中重金属污染物超标的程度。根据这些结果，对于重金属浓度显着超过标准的疏ged污泥，应在填埋污泥之前降低孔隙水中重金属的浓度，并在污泥表面建立覆盖层以控制降雨。浸润。镍是第一个突破低渗透性天然淤泥屏障的重金属污染物。输运参数不仅影响模拟的重金属污染物冲破淤泥层并造成地下环境污染的时间，而且还影响孔隙水中重金属污染物超标的程度。根据这些结果，对于重金属浓度显着超过标准的疏ged污泥，应在填埋污泥之前降低孔隙水中重金属的浓度，并在污泥表面建立覆盖层以控制降雨。浸润。镍是第一个突破低渗透性天然淤泥屏障的重金属污染物。输运参数不仅影响模拟量的重金属污染物冲破淤泥层并造成地下环境污染的时间，而且还影响孔隙水中重金属污染物超标的程度。根据这些结果，对于重金属浓度显着超过标准的疏ged污泥，应在填埋污泥之前降低孔隙水中重金属的浓度，并在污泥表面建立覆盖层以控制降雨。浸润。输运参数不仅影响模拟的重金属污染物冲破淤泥层并造成地下环境污染的时间，而且还影响孔隙水中重金属污染物超标的程度。根据这些结果，对于重金属浓度显着超过标准的疏ged污泥，应在填埋污泥之前降低孔隙水中重金属的浓度，并在污泥表面建立覆盖层以控制降雨。浸润。输运参数不仅影响模拟的重金属污染物冲破淤泥层并造成地下环境污染的时间，而且还影响孔隙水中重金属污染物超标的程度。根据这些结果，对于重金属浓度显着超过标准的疏ged污泥，应在填埋污泥之前降低孔隙水中重金属的浓度，并在污泥表面建立覆盖层以控制降雨。浸润。