珠江口贫氧区沉积物中微量金属元素的地球化学特征

GEOCHEMICAL CHARACTERISTICS OF TRACE METALS IN THE SURFACE SEDIMENTS OF OXYGEN-DEFICIENT WATERS OF THE ZHUJIANG ESTUARY

研究了珠江口贫氧区表层沉积物中Cu,Pb,Zn,Cd,Fe和Mn含量的相互关系;探讨它们在迁移和固-液平衡过程相互作用的特征;研究了沉积物的环境因素和重要组分对其沉积-溶解作用的影响;研究了表层沉积物对它们的富集作用。结果发现,沉积物对Cu,Pb,Zn和Cd的富集系数(K)排列次序为K_(Cd)>K_(Pb)>K_(Cu)>K_(Zn)。K_(Cd)大于对照区和长江口的相应值。此结果说明,上述区域的表层沉积物中可能有自生的CdS。且贫氧水的表层沉积物中Fe,Mn,Cu,Pb和Cd的地球化学特性尚未有显著的改变。

The relationship between the contents for Cu, Pb, Zn, Cd, Fe and Mn in the surface sediments of oxygen-deficient waters of the Zhujiang estuary was analyzed statisti-cally. Their characteristics of interaction in the processes of transport and sold-liquid equilibrium, and the influence of the environmental factors and major compositions of sediment on the deposition-solution process of the surface sediments, as well as the enrichment effect of the surface sediment to the metals were discussed. The result showed that the enrichment factors (K) of the sediment to Cu, Pb, Zn and Cd are arranged in the order of Kc.d>Kpb>Kcu>Kzn, where Kcd value is higher than the ones of the reference area and the Changjiang estuary. This revealed that in the surface sediments of the waters there might be authigenic sediments of CdS, and also no obvious change in geochemical characteristics of the trace metals.