通过黄河包头段打不素、昆都仑河及昆都仑河入黄河口下游断面沉积物分层柱状样中Cu、Pb、Zn和Cd等4种重金属的5种形态与矿物组成及有机质的聚类分析,结合腐植酸对Cu、Pb、Zn和Cd在黄河包头段沉积物中吸附影响实验,进行了黄河包头段沉积物组成对重金属形态分布的影响分析。结果表明,伊利石和绿泥石是黄河包头段水环境中颗粒物携带重金属的主要矿物成分,并对重金属次生相的4种形态均有重要影响;碳酸钙(方解石)通过对水环境中CO3^2-浓度的调节,间接对沉积物中重金属形态产生影响,并影响其他矿物对重金属的运移能力;石英、正长石、斜长石及钠闪石等4种矿物对水环境中重金属的固定作用较小,只对可交换态重金属产生影响;沉积物中有机质因易与水环境中的重金属结合及被沉积物矿物组分吸附,从而影响重金属有机质结合态含量。
Based on cluster analysis on the content of mineral constituent, organic matter and species of heavy metals (Cu, Pb, Zn and Cd) in sediment cores of the Dabusu section, the Kundulun River and the Kundulun estuary, and combining with the experiment of effect of humic acid on the adsorption of heavy metals on surface sediments, the influence of the sediment composition on the distribution of the heavy metals in Baotou section of the Yellow River was studied. The results were as follows: The strong adsorption ability of illite and chlorite which are major clay minerals in the Yellow River and important mineral compositions of carrying the heavy metals via particulates, had significant in. fluence on species distribution of the heavy metals in secondary phase; The regulation effect of calcium carbonate (calcite) on the concentration of CO3^2- had indirect influence on the species distributions of the heavy metals in sediment in aquatic environment, thus affecting the mobility of the heavy metals with other minerals; The quartz, orthoclase, plagioclase and riebeckite had a little effect on the fixation of the heavy metals and the fixed heavy metals were liable to release again, therefore only influencing exchangeable form but not that bound to carbonates, to Fe-Mn oxides and to organic matter; The organic matters in sediments were liable to combine with the heavy metals in aquatic phase and be adsorbed by the mineral constituents in sediments, which led to the strong adsorption of the heavy metals and affected the content of binding forms of the heavy metals bound to organic matter.