孙驰 王俊 吴用 赵胜男

摘 要：为了探究乌梁素海冰体和水体中重金属的行为特征，于2016年12月至2017年3月连续采集乌梁素海典型区域冰体和水体，并将其均匀分层，对冰体和水体中重金属含量进行分析。通过绘制重金属分布图定性描述冻融过程中重金属的分布和迁移规律;通过构建冻结过程和消融过程中重金属冰-水迁移模型，分时段估算了重金属在冰-水界面的迁移通量和迁移总量，并结合冰厚、冰生长率、重金属质量浓度变化率等参数，量化了重金属在冻融过程中的迁移特征。结果表明：在湖水结冰过程中，冰体中重金属质量浓度较低，随着冰厚的增加，冰下水体重金属质量浓度逐渐增大;在湖冰消融阶段，冰体中重金属质量浓度增大，融冰水的淡化作用致使冰下水体中重金属的质量浓度逐渐减小;乌梁素海不同重金属迁移总量Fe>Zn>Mn>Cr>As>Cu>Pb>Hg>Cd。

关键词：乌梁素海;重金属;冻融过程;迁移量;分布特征

中图分类号：TV882.9;X524 文献标志码：A

doi：10.3969/j.issn.1000-1379.2021.08.019

引用格式：孙驰，王俊，吴用，等.乌梁素海重金属在冰-水介质中的行为特征[J].人民黄河，2021，43（8）：102-107.

Abstract： In order to explore the behavior characteristics of heavy metals in the ice and water of Lake Ulansuhai， the ice and water in the typical area of Lake Ulansuhai were collected continuously from December 2016 to March 2017， and the contents of heavy metals in the ice and water were analyzed. The distribution and migration of heavy metals during freezing and thawing were qualitatively described by drawing the distribution map of heavy metals; by constructing the ice water transport model of heavy metals during freezing and thawing process， the transport flux and total amount of heavy metals at the ice water interface were estimated in different periods， and the migration characteristics of heavy metals during freezing and thawing process were quantified by combining with the parameters of ice thickness， ice growth rate and mass concentration change rate. The results show that the mass concentration of heavy metals in the ice is low during the freezing process of the lake water， and the mass concentration of heavy metals in the ice increases with the increase of ice thickness; in the stage of lake ice melting， the mass concentration of heavy metals in the ice body increases， and the mass concentration of heavy metals in the subglacial water gradually decreases due to the desalination of deicing water; the order of the total migration amount of different heavy metals in Lake Ulansuhai is Fe>Zn>Mn>Cr>As>Cu>Pb>Hg>Cd.

Key words： Lake Ulansuhai; heavy metal; freezing-thawing process; migration; distribution characteristics

烏梁素海位于我国蒙新高原湖区中部，是北方寒旱区草型浅水湖泊的典型代表。自20世纪70年代以来，乌梁素海主要承担上游河套灌区的农田退水，这使得湖区水体污染严重，生物多样性遭到破坏，生态功能退化。随着当地经济的快速发展和人民生活水平的提高，湖泊水体近年来遭受着有机污染、盐化污染、重金属污染等[1]。乌梁素海的重金属污染致使湖区生态环境受到严重破坏[2-3]。此外，乌梁素海退水口是乌毛计，退……