SORPTION OF ORGANIC CONTAMINANTS TO AQUIFER SOLIDS

含水层固体中有机污染物的吸附

• 批准号: 3840723
• 负责人: PHILIP M GSCHWEND
• 金额: --
• 依托单位: MASSACHUSETTS INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3840723
• 关键词: adsorption; amorphous solid; biotransformation; diffusion; environmental toxicology; fresh water environment; gas chromatography; ground water; hydropathy; industrial waste; mathematical model; soil; solute; thermodynamics; toluene; toxicant interaction; trichloroethylene; water pollution; water solubility

The long-term objective of this project is to enable us to predict the relevant sorption equilibrium or kinetics for toxic organic compounds present in groundwater environments. Such predictions are necessary, not only to estimate the hazard posed to people living near buried organic wastes and using the surface and subsurface waters polluted by these chemicals, but also to evaluate many clean-up strategies which rely on compound desorption to enable (bio)degradation or removal in pumped water or soil air. The experimental design involves first establishing an equilibrium description for real world subsurface solids acting as sorbents, and then tackling the kinetics problem by identifying the slowest solid-water exchange step beginning at the grain scale and working up to larger and larger scales. First, we hypothesize that nonpolar compound sorption to subsurface minerals (with very low organic contents) involves dissolution in "vicinal" waters filling the solid-phase micropores. By examining the correlation of microporosity and sorptive equilibrium coefficients, we hope to demonstrate the validity of this hypothesis. Next, we speculate that long-term sorptive exchange is limited by the rate of transfer of sorbate molecules into the microporous space of larger grains. We will seek to relate the volume of microporous space and the magnitude of K(D) to the observed rates of uptake and release of sorbates like trichloroethylene. This will help us ascertain the controlling sorption mechanism(s). To gauge the importance of such grain-scale kinetics, we will compare the observed rates with those we see from a set of flow- interrupt breakthrough experiments relying on short, but intact, soil cores drawn from sites within the Aberjona Basin.

该项目的长期目标是使我们能够预测 有毒有机化合物的相关吸附平衡或动力学 存在于地下水环境中。 这样的预测是必要的，而不是 只是为了估计对生活在埋藏有机物附近的人们造成的危害 废物并利用受这些废物污染的地表水和地下水 化学品，还可以评估许多依赖于 化合物解吸以实现泵送水中的（生物）降解或去除 或土壤空气。 实验设计首先涉及建立平衡 描述现实世界中作为吸附剂的地下固体，然后 通过识别最慢的固体水来解决动力学问题 交换步骤从颗粒尺寸开始，逐步扩大到更大的尺寸 规模更大。 首先，我们假设非极性化合物吸附 地下矿物（有机含量非常低）涉及溶解 在填充固相微孔的“附近”水域中。 通过检查 微孔率和吸附平衡系数的相关性，我们 希望证明这一假设的有效性。 接下来我们推测 长期吸附交换受到转移速率的限制 山梨酸盐分子进入较大颗粒的微孔空间。 我们将 寻求将微孔空间的体积与 K(D) 的大小联系起来 观察到的山梨酸盐的吸收和释放速率，例如 三氯乙烯。 这将帮助我们确定控制吸附 机制。 为了衡量这种颗粒级动力学的重要性，我们 将观察到的速率与我们从一组流中看到的速率进行比较 中断依赖于短暂但完整的土壤的突破性实验 从阿伯霍纳盆地内的地点抽取的岩心。