Navia Rodrigo, Fuentes Bárbara, Diez María C, Lorber Karl E
Chemical Engineering Department, University of La Frontera, P.O. Box 54-D, Temuco, Chile.
Waste Manag Res. 2005 Jun;23(3):260-9. doi: 10.1177/0734242X05054281.
The volcanic soil of Southern Chile was tested for its heavy metal retention capacity. The maximum uptakes for CrO4(2-) (CrVI), Cu(2+), Zn(2+) and Pb(2+) were determined to be 2.74, 5.32, 5.86 and 7.44 mg g(-1), respectively. At a slightly alkaline pH value (7.5), it seems that a precipitation-adsorption process was responsible for the Cu(2+) and Zn(2+) uptake onto volcanic soil. All the determined values are of the same order of magnitude as natural zeolites heavy metals adsorption capacities. In addition, the heavy metals diffusion model through a 1 m volcanic soil mineral liner shows breakthrough times of 21.6, 10.2 and 8.9 years, for Pb(2+), Zn(2+) and Cu(2+), respectively, confirming the trend obtained in the adsorption isotherms. The natural volcanic soil of Southern Chile is an interesting material for possible use as landfill mineral basal sealing. It has an appropriate sealing potential (average Kf value of 5.85 x 10(-9) m s(-1)) and a heavy metals retention capacity comparable with natural zeolites. About two-thirds of the agricultural land in Chile (approximately 0.4 million km2) is derived from volcanic ash, suggesting an important soil volume for future landfill projects, that could be obtained in sufficient quantities from urban building activities.
对智利南部的火山土壤进行了重金属保留能力测试。测定出CrO4(2-)（六价铬）、Cu(2+)、Zn(2+)和Pb(2+)的最大吸收量分别为2.74、5.32、5.86和7.44 mg g(-1)。在略呈碱性的pH值（7.5）下，Cu(2+)和Zn(2+)在火山土壤上的吸收似乎是由沉淀 - 吸附过程导致的。所有测定值与天然沸石的重金属吸附能力处于同一数量级。此外，通过1米厚的火山土壤矿物衬层的重金属扩散模型表明，Pb(2+)、Zn(2+)和Cu(2+)的穿透时间分别为21.6年、10.2年和8.9年，这证实了吸附等温线中得出的趋势。智利南部的天然火山土壤是一种有潜力用作垃圾填埋场矿物基础密封材料的有趣材料。它具有合适的密封潜力（平均Kf值为5.85×10(-9) m s(-1)）以及与天然沸石相当的重金属保留能力。智利约三分之二的农业用地（约40万平方公里）源自火山灰，这表明未来垃圾填埋项目有大量的土壤可用，且可从城市建筑活动中获取足够数量的土壤。
