中文摘要：

应用模拟试验方法,研究了外源As（Ⅲ）在第四纪红土、紫色砂页岩和花岗岩3种母质发育土壤中的老化过程,并分析了该过程中砷的有效性、结合态等的变化.结果表明：经过120 d老化后,3种土壤中均只能检测到As（Ⅴ）的存在;伴随老化过程的进行,土壤中有效态砷的含量均呈下降趋势,且下降幅度为：紫色砂页岩发育土壤（RS2）〉花岗岩发育土壤（RS3）〉第四纪红土发育土壤（RS1）.应用准二级动力学方程可以较好地模拟3种土壤中有效态砷含量的变化（P〈0.05）,土壤p H、有机质及铁铝锰氧化物是影响砷老化的主要因素,且锰氧化物的影响大于铁铝氧化物（P〈0.05）.相关分析表明,非专性吸附态砷和专性吸附态砷是构成土壤有效砷的主要形态.

英文摘要：

An incubation test was conducted to study the bioavailability and fractionations of exoge- nous arsenite [ As （ Ⅲ ） ] during the aging period in three soils originated from different parent materials, including quaternary red clay, purple sandy shale and granite. The results indicated that the exogenous arsenite As（ Ⅲ ） were totally transformed into As（V） after 120 d aging. The available As content in soils derived from the three soils generally decreased sequentially throughout the aging period in the order of purple sandy shale, granite and quaternary red clay. The pseudo-second-order model well fitted the change of available As content with aging time （P〈0.05）. Soil pH, organic matter （SOM） content and the concentrations of Fe, A1 and Mn oxides were the main factors influencing the red soil arsenic in aging, especially, Mn oxides played a more crucial role than Fe and A1 oxides in As aging （P〈0.05）. Correlation analysis absorbed As constituted the primary forms of available revealed that the non-specially and specially As.