在线金汞齐浓集冷原子吸收法测定海水中p mol/dm3级汞

将在线两步金浓集与冷原子吸收法结合,测定海水中p mol/dm~3级汞。用国产有机金水制备涂敷金膜玻璃微珠,并对还原剂用量,介质酸度、载气流量、反应时间、加热及浓集方法等进行了条件实验,选取最佳条件。该法对海水中汞的测定检出限约为1p mol/dm~3,比普通直接冷原子吸收法降低一个数量级。对p mol/dm~3级汞的海水,测定相对标准偏差<10％。海水盐度对测定结果无明显影响。对我国部分近岸海水及河口水中弱结合汞的测定表明,其浓度与世界近海和外海水中的近期测值相当。     

DYNAMIC MODEL FOR OIL SLICK DISPERSION INTO A WATER COLUMN- A WINDDRIVEN WAVETANK EXPERIMENT

A dynamic experiment for oil dispersion into a water column was performed with a 21 m long, 0.5 m wide, and 1 m high wind-driven wave tank. At wind velocity between 6-12 m/s and with the oil slide kept constant (about 1 um), the rate of the oil content increase in the water column could be approximated from the difference between the dispersion rate (R) of the oil slick and the coagulation rate (R') of the dispersed oil slick. Assuming the coagulation rate is directly proportional to the concentration of the water dispersed oil slick (i. e. R' =KC),, the integral form of the dynamic model can be expressed as C=R*[1-exp(-K*t)]/K and parameters R and K can be regressed with a computer. The relative deviation of model results from the experimental data was mainly less than 10%. The oil slick dispersion rate (R) had exponential relationship with the wind velocity (V), and can be fitted with a formula R=A*(U+1)B.The fitted constant of the coagulation rate, K(0.8-3.0* 10-3 min-1) did not have significant rela     

中型海洋围隔生态系中汞通量、形态和收支的研究

在海洋围隔生态系实验中加入迄今最低浓度的无机汞,以研究汞的迁移通量、形态分布和收支。加汞后,汞从水柱中被排除的行为可用一级反应动力学描述。在该生态系内汞被排除的半寿期,与初级生产力和浮游植物特性如个体大小、浮游能力等有关。对照围隔生态系内,0.01μg Hg/cm~2·a的汞垂直通量与海湾现场测量值一致。在自然条件下,溶解汞是水中的主要形态,占73％。加汞后,颗粒汞迅速上升,可达70％以上。浮游植物对汞的富集因子为10~5级。汞在沉积物、器壁和水体中的回收只占52.3％。     

沙奈奇湾汞的通量研究

用近岸沉积物捕集器测定了沙奈奇湾5站位不同深度的汞、沉积颗粒物和有机碳通量。通量值与生产力有一致的季节变化,而且比太平洋值高约1—2个数量级。与水柱中汞浓度值结合,计算出汞在沉积物-水间的分配系数(155级)和汞的停留时间(2.4年)。     

A STUDY ON THE FLUX, SPECIATION, AND BUDGET OFMERCURY IN CONTROLLED EXPEEIMENTAL ECOSYSTEMS

The lowest addition of mercury (0.1 ug Hg 1-1) was used in CEEs for research on mercury flux, speciation and budget. The removal behavior of mercury by phytoplankton in water columns of CEEs can be described by first order kinetic equations for total and particulate mercury in the CEE spiked by mercury. The removal rate of mercury in water columns depends on the size and productivity of phytoplanton in a water column to which mercuric ions were added. A 4.4 day half-life time and a 2.8 day half-life time for total and particulate mercury respectively was obtained in diatom bloom. During microflagellate bloom a 30 day total mercury half-life time was estimated with increase of particulate mercury in the water column. The 0.010 ug Hg cm-2y-1 mercury flux rate that was attained in the control bag agreed with the values from field measurements in Saanich Inlet where the bags Were launched.The proportion of total mercury to dissolved and particulate mercury depended also on the size, productivity, and concen