中文摘要：

关于重金属污染的风险评价及其预测模型日益成为环境领域的研究热点。近年来,一种用于预测和评价环境中重金属生物毒性的机理性模型一生物配体模型（BLM）被广泛应用于水体及陆地生态系统。本研究以我国土壤的陆地生物配体模型（TBLM）建构为目标,以土壤溶液系统为媒介,通过17种土壤上重金属铜离子与大麦根长的相互作用关系,发现了土壤中Cu-TBLM的主要影响因素为Cu2＋、CuOH＋、Mg2＋以及铜离子与大麦根系表面的专性结合能力。基于模型大麦根长预测值与实测值之间的相关关系,通过数学拟合功能求得TBLM中各参数值为logKCuBL=4.87、logKCuOH＋=7.62、logKMgBL=1.91、f50%=0.103、β=1.09。本研究所得到的TBLM模型能很好地预测我国土壤中铜对大麦根长的毒害程度,预测值与实测值的相关性达到了90%。本研究结果不仅可以为我们降低重金属离子生物有效性提供有力的理论借鉴,更对我国土壤环境质量保护和长期良性可持续发展具有重要意义。文160余篇。

英文摘要：

The terrestrial biotic ligand model （TBLM） is a newly developed method for evaluating bioavailability of heavy metal ion in soils. Seventeen soil samples covering China were selected in this study by adding a series of Cu concentrations. The soil solutions were extracted according to the method of maximum water holding capacity. The cation and anion concentrations as well as dissolved organic carbon （DOC） in soil solu- tions were measured for the predictions ofCu （Cu2＋ and CuOH＋ especially at high - pH conditions）and Mg ion activities. The WHAM 6 model was used to predict free Cu2＋, CuOH＋ and Mg2＋ activities using 65% DOM as active fluvic acid （FA） and adjusted binding constant 1OgKcuFA = 1.5. The predicted ion activities and measured barley relative root elongation as variables were input into TBLM equation, and binding constants and parameters were fitted out as 1OgKcuBL = 4.87, IogKcuoH＋ = 7.62, 1ogK fl = 1.09 by DPS statistic software according the best agreement between measured and predicted barley relative root lengths. The results showed that predicted and measured barley root elongation can match quite well with an R2 = 0.90, RMSE = 11.4 and almost all predicted values lied within 2-fold of measured values. In order to ensure accuracy of TBLM in our study, some parameters from relative studies were compared with the values in this study, which showed that our TBLM was better than others and more suitable for Cu prediction of bioavailability in Chinese soils because a series of high-pH soils samples were included. The study will help a lot on formulating guidance of soil environment risk assessments not only for China but for the other areas around world.