体外消化法评价稳定剂对土壤重金属的稳定效率

Evaluation of Stabilization Efficiency of Stabilizers for Heavy Metals in Soil by Vitro Digestion

土壤重金属污染已成为全球性问题,重金属对人体的危害性已得到广泛的认同,人们采取各样的措施控制和消减重金属的危害。可靠地评估人体经口摄入的土壤中的有毒重金属的有效性,已成为提高我国人民健康质量所不可忽视的焦点问题之一。采用SBET(Simple Bioavailability Extraction Test)评价法研究稳定剂对污染土壤中重金属的稳定效率。三种稳定剂组合分别为T_(1):H_(3)PO_(4)+CaO;T_(2):Na_(2)S+Ca CO_(3);T_(3):H_(3)PO_(4)+Na_(2)S+CaCO_(3)。结果表明,在SBET提取条件下,含(含磷物质)T_(1)和T_(3)有利于磷酸盐沉淀或矿物的形成,可导致Pb和Cd的生物可给度被低估,经T_(1)和T_(3)稳定后,各土壤As的生物可给度升高。经T_(2)(含硫物质)稳定后,各土壤As的生物可给度降低,表明在哺乳动物消化系统内,磷酸根离子与砷酸根离子之间存在着竞争吸附。

Heavy metals contaminated soil has become a global issue. The hazards of heavy metals to human health have been well recognized. At present, human beings take varied methods to reduce the harm and to control the heavy metal’s translation. In many cases, oral ingested soil has become an important source of heavy metals in human. Evaluation on the bioaccessibility of toxic heavy metals in the soil through mouth to human body reliably has become the focus of people’s life quality which can’t be ignored. In this article, SBET(simple bioavailability extraction test)was used to study the stabilizing efficiency of stabilizers on heavy metals in contaminated soil. Three stabilizer combination respectively was as follows T_(1): H_(3)PO_(4)+CaO;T_(2):Na_(2)S+CaCO_(3);T_(3): H_(3)PO_(4)+ Na_(2)S+CaCO_(3). The result showed that including phosphorus material(T_(1) and T_(3)) was beneficial to the formation of phosphate precipitation or mineral, which led to give a low value of Pb and Cd bioaccebility in SBET extraction conditions.After the T_(1) and T_(3) stability, the soil As bioability could give a degree rise;After the T_(2)(including sulpfur material) stability, the soil As creatures could give a lower degree,which showed that phosphate ions and arsenic ion existed adsorption competition in the digestive system in mammals.