湛江东海岛潮间带沉积物硫化物（AVS）和重金属（SEM）及其生物毒效性评估

摘要

The content and distribution of acid-volatile sulfide (AVS) and simultaneously extracted metals (SEM) (Cr Cu, Zn, Cd and Pb) were studied in surface sediments col ected from the tidal flat of Donghai Island, Zhanjiang. The results indicated that for most stations, the AVS concentration was higher in summer with the average of 0.449mmol/g than that in winter with the average of 1.816mmol/g. The AVS contents were higher in southern and northern areas and lower in western and eastern areas. The average content of ∑SEM was between 0.56 mmol/g and 4.60 mmol/g in summer and between 0.65mmol/g and 2.21mmol/g in winter. The concentration change of single metal was Zn>Cr>Pb>Cu>Cd for most stations. The content percentage in ∑SEM was below 1%for Cd and over 70%for Zn. SEMZn was the key pattern to control the distribution of ∑SEM due to its high concentration percentage. Based on the assessment methods of (∑SEM/AVS) with (∑SEM-AVS) and thresholds for metal toxicity to benthic organism, most values of (∑SEM-AVS) in intertidal flats of Donghai Island were between 0 and 5. The most toxicity region was in Tongminghai area located in the west tidal zone of Donghai Island, and the most toxicity metal was zinc in Tongminghai area in summer. The land-based pol ution and the environmental parameters such as sunlight, atmosphere temperature and hydrodynamic characteristics were the main affecting factors on the content level and distribution characteristics of AVS and SEM in intertidal sediments of Donghai Island.%对湛江东海岛潮间带表层沉积物中酸可挥发性硫化物（AVS）和同步提取重金属（SEM）的含量及其分布进行了研究。研究表明，东海岛潮间带表层沉积物中 AVS 含量夏季平均为0.449mmol/g，冬季为1.816mmol/g，大多数站位 AVS 含量冬季高于夏季；AVS 平均含量总体呈南、北区较高，东、西区较低的区域分布规律。潮区沉积物可提取重金属SEM总量夏季在0.56mmol/g ～4.60mmol/g之间，冬季处于0.65mmol/g ～2.21mmol/g之间；各重金属平均含量大小为Zn>Cr>Pb>Cu>Cd，其中Cd含量占SEM总量不到1%，Zn含量则在70%以上，SEMZn是控制着SEM分布的主要模式。联合利用（∑SEM/AVS）与（∑SEM-AVS）法和生物毒性阈值法综合评估重金属对沉积环境的影响，东海岛潮间带大部分区域沉积物中（∑SEM-AVS）处于0～5之间，重金属潜在生物毒性较强的区域为通明海区（7号站和8号站所在），具有较强潜在生物毒性的重金属为夏季通明海区的Zn。