重金属污染底泥泥沙粒径分布与重金属富集规律研究

Research on particle size distribution and heavy metal enrichment of polluted sediment

通过分析典型泥质河流(泥质、泥沙混合质)中重金属污染底泥的泥沙粒径分布与重金属富集的规律,结合相关资源化利用标准,确定底泥粒径筛分目标,进而为河流疏浚工程中底泥的资源化利用提供参考.实验结果表明:泥质底泥均以粒径<75μm的泥沙为主,沙质底泥以粒径>150μm的泥沙为主;不同泥质重金属污染底泥中不同粒径泥沙的重金属和有机质含量变化趋势一致,基本随着粒径的减小而增大;A河(泥质)底泥建议的筛分目标是150μm,筛上底泥适于建材利用;B河(泥沙混合质)底泥建议的筛分目标是300μm,筛上底泥适于园林利用、土地改良、建材利用.该实验为今后的河流清淤工程提供了一种更好地实现重金属污染底泥资源化利用的方法.

The law of particle size distribution and heavy metal enrichment of polluted sediment in two different type rivers（muddy,muddy and sandy）are analyzed in combination with the standards of resource utilization.With the aim to determine the sieving target of the particle size in sediment,the paper provides reference for the sediment resource utilization.The experimental results indicate that muddy sediment is dominated by the particle size〈75μm sediment,and sandy sediment is dominated by the particle size〉150μm sediment;the content change tendency of heavy metals and organic matters in the different argillaceous sediments are consistent,which basically increased with the decreased of particle size.The proposed target of sieved sediment in river A is focused on the particle size of 150μm,and the sieved sediment is suitable for using as building materials;the proposed target of sievedsediment in river B is the part of 300μm,and the sieved sediment is suitable for landscape application,land improvement and building materials utilization.This research offers a better method for realizing the resource utilization of heavy metal pollution sediment for river dredging engineering in future.