人工甜味剂在不同类型土壤中的淋溶行为研究

Study on the Leaching Behavior of Typical Artificial Sweeteners in Soils

人工甜味剂(artificial sweeteners)是一类人工合成或半合成的蔗糖替代品,广泛应用于食品、药物、个人护理品和饲料中,但是大多数人工甜味剂在人和动物体内几乎不被代谢而随尿液和粪便直接进入环境。在天津污水河沿线及甜味剂厂附近不同深度土层中检测到安赛蜜、糖精、甜蜜素和三氯蔗糖。为探讨人工甜味剂在土壤中的移动性及其对地下水污染的风险,应用土柱淋溶实验研究了安赛蜜和三氯蔗糖在2种土壤中的淋溶行为,并观测了人工甜味剂淋溶对土柱淋出液的溶解性有机质(DOM)、pH以及电导率(EC)的影响。结果表明安赛蜜和三氯蔗糖在2种土壤中表现出较强的移动性,超过87%的甜味剂均被淋出,只有不到13%的甜味剂被土壤截留或损失,因此对地下水具有较大的风险。安赛蜜和三氯蔗糖能够促进土壤溶解性有机质的溶出,但对淋出液的pH和电导率无显著影响。

Artificial sweeteners（ASs） are used worldwide as sugar substitutes in remarkable amounts in food, pharmaceuticals, personal care products as well as in animal feed, however, the majority of artificial sweeteners ingested by human and animals are almost not absorbed or metabolized and get into environment through the urine and feces directly. In this study, acesulfame, saccharin, cyclamate, and sucralose were detected in different soil layers along a sweage canal and around a sweetener factory in Tianjin. Soil column leaching experiments on acesulfame and sucralose were conducted to study their mobility and the possible risk to contaminate ground water. The results showed that more than 87% of the two tested sweeteners were detected in leachates and less than 13% of them existed insoil column or lost, mainly in the deep layer, indicating the strong mobility. Therefore, it may cause risk to groundwater. Furthermore, the influence of acesulfame and sucralose on dissolved organic matter（DOM）, pH and electrical conductivity（EC） of the leachates were measured. The results indicated that both of the two artificial sweeteners could enhance the leaching of DOM, while they rarely had any impact on pH or EC of the leachates.