沿海表层沉积物中重金属的有效结合态

以浙江沿海表层沉积物为研究对象,系统地研究了重金属有效结合态与沉积环境、矿物组成和人为排放等环境因素之间的相互关系.结果表明:沿海表层沉积物中重金属的积累数量,呈现出潮汐河口沉积物>沿海沉积物>强潮汐河口沉积物的趋势,这反映了不同沉积类型对重金属富集作用的差异;重金属的有效结合态,总体上以铁锰氧化物结合态>碳酸盐结合态>硫化物及有机结合态>可交换态的顺序存在,但是不同的重金属或同种重金属在不同的采点,主要有效结合态的比例存在明显的差异,这不仅与重金属的地球化学性质、沉积环境和沉积物中的粘土矿物组成有关,更受到重金属污染物的人为排放量的影响.

APPROACH TO EFFECTIVE SPECIES OF HEAVY METALS IN COASTAL SURFICIAL SEDIMENTS

The heavy metal effective species, sedimentary environment, mineral compositions and heavy metals released by human activities in surficial sediments along Zhejiang coastal area were studied. The results revealed that the accumulative amount of heavy metals having a tendency towards tidal estuary sediment > coastal sediment > stronger tidal estuary sediment, which reflected the difference of enrichment of heavy metals with various types of sediments. The effective species of heavy metals showed metals bound to Fe Mn oxides > metals bound to carbonates > metals bound to sulphide and organic matter > exchangeable metals. Obviously, the distribution of heavy metals and its major effective species were varied from place to place, which was related not only to the heavy metal geochemistry behavior, sedimentary environment and clay minerals, but also closely to release by human activities.