摘要:
内分泌干扰物(EDCs)作为一种新兴污染物,具有憎水性、低剂量效应和半衰期长等特征,在全球的土壤/沉积物中已被广泛检测到,并发现已给环境带来了严重的威胁。本文重点综合评述了近10年来土壤/沉积物中EDCs的来源、浓度水平、空间分布及吸附特性的研究。结果发现,EDCs来源涉及农业、工业和生活等多个方面;空间分布上,一般呈近海地区沉积物中EDCs浓度水平较河流底泥及土壤低,而高度工业化、城市化地区土壤/沉积物中EDCs浓度亦较高;EDCs的吸附受土壤/沉积物理化性质、EDCs自身性质和环境条件的共同影响,一般土壤有机质的含量和成熟度、土壤颗粒的比表面积与其吸附能力呈正相关,黏土矿物类型对EDCs的吸附也有重要的影响;EDCs的吸附能力与其自身的疏水性和结构特征有关;温度升高和溶液pH值增加都不利于EDCs的吸附,而溶液离子强度的增加对其吸附起着促进作用。土壤/沉积物对EDCs的吸附是一个复杂的过程,因此对其吸附特性需要进一步的探讨。
Abstract:
Endocrine disrupting compounds (EDCs), a kind of emerging pollutant, have the character of hydrophobicity, low-concentration effects and long half-life. They have been globally detected (and are still being detected) in soils/sediments, making a serious menace to the environment. In this paper, the sources, concentrations, spatial distribution and adsorption properties of EDCs in soil/sediments are comprehensively reviewed. Numerous publications have shown that the sources of EDCs involved agriculture, industry and household wastes. In spatial distribution, the concentration of EDCs in marine sediments is usually lower than that in river sediments, and the levels of EDCs in soils/sediments of urbanized and highly industrial areas are much higher. In terms of adsorption property of EDCs, it has been affected by the physicochemical properties of soils/sediments, its own characters and the environmental conditions. In general, the adsorption capacity is positively correlated to the organic contents in soil, the soil maturity and the specific surface area of soil particles. The type of clay minerals also has influences on the adsorption. In addition, the hydrophobicity and structural features are related to the adsorption capacity. The increase of temperature and pH shows the disadvantages to the adsorption of EDCs, while the increase of ionic strength has a positive effect. In summary, the adsorption of EDCs on soils/sediments is a complex process, which needs further explorations.