环境中金属生物有效性的预测模型——生物配体模型研究进展

生物配体模型(BLM)是一种用于预测环境中金属生物毒性的机理性模型.模型理论起源于自由离子活度模型(FIAM)和鱼鳃络合模型(GSIM),考虑了自由金属离子的活度以及自然环境存在的其他离子(如Ca2+、Na+、Mg2+、H+)、非生物配体(如可溶性有机质、氯化物、碳酸盐、硫酸盐)和生物配体的竞争.目前,在水生生态系统中,基于鱼鳃络合模型的框架基础,通过生物化学实验手段并结合数学方法,建立了预测铜、锌、银、镍对Rainbowtrout(虹鳟鱼)、Fatheadminnow(黑头呆鱼)和Daphniamagna(水蚤)的急、慢性毒性的BLM版本,并积极探索其在陆地生态系统中的应用.虽然生物配体模型在实验室模拟条件下取得了较为满意的结果,但其中包含着一些假设,在实际应用中还具有一定的局限性,尤其是陆地生态系统生物配体模型的发展还需要做许多研究工作.本文主要论述了生物配体模型的理论基础、实现手段和应用情况,讨论了生物配体模型的优势和局限性并对其未来研究方向进行了展望.

Advances in Biotic-Ligand Model to Predict the Bioavailability of Metals in Environments

The Biotic-ligand Model(BLM)is a mechanistic model used to predict the ecotoxicity of metals in environments. The theory of the BLM evolves from Free-Ion-Activity Model(FIAM)and Gill Surface Interaction Model(GSIM), and incorporates the competition of the free metal ion with other naturally occurring cations(e.g. Ca2 , Na , Mg2 , H ), together with complexation by abiotic ligands(e.g. DOM, chloride, carbonates, sulfide)for binding with the biotic ligand. Using biochemistry and mathematics methods, different versions of acute and chronic BLM for the toxicity of Cu, Zn, Ag and Ni to fish(Rainbow trout, Fathead minnow)and Daphnia magna in aquatic ecosystems had been published. Although the BLM was found to be satisfactory in laboratory conditions, but there are some limitations in practice, especially in terrestrial ecosystems. In this article, theoretical basis, development, application and the limitations of BLM were reviewed, meanwhile the investigation in the future were prospected.