Institute of Environmental Assessment and Water Research (IDAEA), CSIC, 08034 Barcelona, Spain.
J Hazard Mater. 2010 May 15;177(1-3):1102-11. doi: 10.1016/j.jhazmat.2010.01.034. Epub 2010 Jan 13.
Reactive transport modelling of the main processes related to the arsenic natural attenuation observed in the acid mine drainage (AMD) impacted stream of Tinto Santa Rosa (SW Spain) was performed. Despite the simplicity of the kinetic expressions used to deal with arsenic attenuation processes, the model reproduced successfully the major chemical trends observed along the acid discharge. Results indicated that the rate of ferrous iron oxidation was similar to the one obtained in earlier field studies in which microbial catalysis is reported to occur. With regard to the scaled arsenic oxidation rate, it is one order of magnitude faster than the values obtained under laboratory conditions suggesting the existence of a catalytic agent in the natural system. Schwertmannite precipitation rate, which was represented by a simple kinetic expression relying on Fe(III) and pH, was in the range calculated for other AMD impacted sites. Finally, the obtained distribution coefficients used for representing arsenic sorption onto Fe(III) precipitates were lower than those deduced from reported laboratory data. This discrepancy is attributed to a decrease in the schwertmannite arsenate sorption capacity as sulphate increases in the solution.
对与西班牙特内里费圣罗莎（Tinto Santa Rosa）酸性矿山排水（AMD）受影响溪流中观察到的砷自然衰减相关的主要过程进行了反应性迁移建模。尽管用于处理砷衰减过程的动力学表达式很简单，但该模型成功地再现了沿酸性排放物观察到的主要化学趋势。结果表明，二价铁氧化速率与先前在微生物催化作用发生的现场研究中获得的速率相似。就砷氧化的比例速率而言，它比在实验室条件下获得的值快一个数量级，这表明在自然系统中存在一种催化剂。依赖于 Fe(III)和 pH 的简单动力学表达式表示水铁矿沉淀速率，其范围与其他 AMD 受影响地点的计算值一致。最后，用于表示砷在 Fe(III)沉淀物上吸附的获得的分配系数低于从报告的实验室数据推断出的系数。这种差异归因于随着溶液中硫酸盐的增加，水铁矿砷酸盐的吸附能力降低。
