重金属在水环境中形态分布的随机模拟

STOCHASTIC MODELLING OF HEAVY METAL SPECIES DISTRIBUTION IN WATER ENVIRONMENT

水环境中重金属的毒性，生物可给性，以及活性均与其存在形态密切相关。而重金属的存在形态是由其容量控制参数决定的。水环境中，重金属的容量控制参数在空间上和时间上发生随机变化。本文的目的在于研究容量控制参数的随机变化对重金属形态分布的影响。作者以洋河汞污染为例，将形态分布模型同ＭｏｕｔｅＣａｒｌｏ方法相结合，模拟了河水中ｐＨ值，有机质浓度，总汞含量，以及悬浮物含量的随机变化对汞形态分布的影响。研究结果表明：①容量控制参数的概率分布与汞形态的概率分布不一致；②不能采用河流水质的平均状况来推断汞形态分布的平均状况；

The toxicity, bioavailability, and mobility of heavy metals in water environment depend on their species distribution, which is controlled by CCP (Capacity Coutrolling Parameters). But, CCP vary spatially and temporally in water environment so far, the effect of the stochastic variation of CCP on the distribution of heavy metal species is not well understood. Taking Hg in the Yanghe River as a case study, the authors employ a hybrid model of speciation model and Moute Carlo model to investigate the effect of the stochastic variation of pH value, organic matter concentration, Hg concentration and particulate content in the Yanghe River on Hg species distribution. Results suggest that ① the probability distribution patterns of CCP are different from those of Hg species. ② the average distribution of Hg species can not be derived from the average water quality. ③ in some cases, the variance of Hg species is a nonliner function of CCP′s variance. These findings can be applied to the uncertainty analysis of geochemical modelling.