硫酸铝对苏打盐碱土中氟迁移规律的影响

采用土柱淋洗法,研究不同铝氟摩尔比下苏打盐碱土中氟的迁移过程及pH值变化情况。结果表明,苏打盐碱土施铝后,能够明显降低淋洗液的pH值,与空白相比,差异均达极显著水平。并且随着淋洗次数和铝相对含量的增加,pH值呈现逐渐降低的趋势。不同铝氟摩尔比作用下,氟在碱土中的迁移动态及总淋失率存在较大的差别。随着淋洗次数的增加,1∶1处理的每次淋失率变化较缓,(1∶2)～(1∶4)处理呈先增加后降低的趋势,而(1∶5)～(1∶7)处理明显下降。与对照相比,苏打盐碱土上施用硫酸铝可以降低氟在土壤中的总淋失量,进而可以减少土体中的氟向地下水中的迁移,降低人畜通过饮用地下水而带来的摄氟量。但是氟总淋失率的降低程度与铝的相对含量有关,其中1∶4铝氟处理的总淋失率相对较高,而1∶1处理的淋失率相对较低。这可能与添加硫酸铝后苏打盐碱土的pH值变化、铝氧化物和氢氧化物数量变化、土壤胶体带电性变化及土壤自身铝的释放有关。

Effect of Aluminum Sulfate on the F Migration Regularity in Soda Alkali-Saline Soil

The paper researched F migration regularity and the change of pH in soda alkali-saline soil at different ratio of Al3+ and F-by leaching method.The results showed that,pH of eluent was decreased obviously by applying aluminum sulfate to soda alkali-saline soil which showed extremely significant difference compared with the blank control.And a decreasing tendency of pH was found when leaching times and the relative content of Al3+ were increasing.There were great differences in the dynamic migration and total leaching loss rate of F under the action of different ration of Al3+ and F-in the soil.The leaching loss rate of each time changed little for 1∶1 treatment,decreased slightly after an increase for treatments of（1∶2）^1∶4,decreased obviously for treatments of（1∶5）^1∶7.Compared to the control,the total leaching loss rate was decreased in soda alkali-saline soil by applying aluminum sulfate.So it could decrease F migration from soil body to groundwater and reduce daily fluoride intake for people and animals by drinking groundwater.But the degreased degree of total F leaching loss rate was relevant to the relative content of Al3+.It was relative higher for 1∶4 treatment and lower for 1∶1 treatment due to the change of pH,quantity of Al oxide and hydroxide,electric charge of soil colloid and aluminum releasing by soil itself.