{"title":"通过数值模拟深入了解污染物释放曲线的相似性与平衡程度之间的关系。","authors":"Yukari Imoto","doi":"10.1016/j.jconhyd.2024.104451","DOIUrl":null,"url":null,"abstract":"<div><div>The assumption of local equilibrium, especially in test standards for assessing the leaching of hazardous substances from materials, is crucial for the use of test results and the robustness of testing. However, previous studies of contact time conditions in percolation test standard have evaluated equilibrium and robustness separately. Therefore, this study tests the assumption of local equilibrium in the up-flow percolation test, standardized as ISO 21268-3 in 2019, and discusses the relationship between the similarity of test results and degree of equilibrium. Thus, we conducted approximately 6000 numerical simulations in total with varying leaching parameters to determine breakthrough curves (BTCs) for the substances investigated by the test standard. The results showed that the two BTCs for the longest and shortest contact time conditions within the standard test were identical over a wide range of parameters, supporting the robustness of the standard test. Interestingly, identical BTCs occur in equilibrium or near-equilibrium and nonequilibrium leaching. This finding indicates the need to reconsider the conventional interpretation that equilibrium is reached when test results with different contact time conditions appear identical and encourages efforts to develop procedures to verify equilibrium leaching.</div></div>","PeriodicalId":15530,"journal":{"name":"Journal of contaminant hydrology","volume":"267 ","pages":"Article 104451"},"PeriodicalIF":3.5000,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Insight into the relationship between similarity and the degree of equilibrium of contaminant release curves through numerical simulations\",\"authors\":\"Yukari Imoto\",\"doi\":\"10.1016/j.jconhyd.2024.104451\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>The assumption of local equilibrium, especially in test standards for assessing the leaching of hazardous substances from materials, is crucial for the use of test results and the robustness of testing. However, previous studies of contact time conditions in percolation test standard have evaluated equilibrium and robustness separately. Therefore, this study tests the assumption of local equilibrium in the up-flow percolation test, standardized as ISO 21268-3 in 2019, and discusses the relationship between the similarity of test results and degree of equilibrium. Thus, we conducted approximately 6000 numerical simulations in total with varying leaching parameters to determine breakthrough curves (BTCs) for the substances investigated by the test standard. The results showed that the two BTCs for the longest and shortest contact time conditions within the standard test were identical over a wide range of parameters, supporting the robustness of the standard test. Interestingly, identical BTCs occur in equilibrium or near-equilibrium and nonequilibrium leaching. This finding indicates the need to reconsider the conventional interpretation that equilibrium is reached when test results with different contact time conditions appear identical and encourages efforts to develop procedures to verify equilibrium leaching.</div></div>\",\"PeriodicalId\":15530,\"journal\":{\"name\":\"Journal of contaminant hydrology\",\"volume\":\"267 \",\"pages\":\"Article 104451\"},\"PeriodicalIF\":3.5000,\"publicationDate\":\"2024-11-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of contaminant hydrology\",\"FirstCategoryId\":\"93\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0169772224001554\",\"RegionNum\":3,\"RegionCategory\":\"环境科学与生态学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"ENVIRONMENTAL SCIENCES\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of contaminant hydrology","FirstCategoryId":"93","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0169772224001554","RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENVIRONMENTAL SCIENCES","Score":null,"Total":0}
引用次数: 0
摘要
局部平衡的假设,尤其是在评估材料中有害物质沥滤的测试标准中,对于测试结果的使用和测试的稳健性至关重要。然而,以往对渗滤测试标准中接触时间条件的研究是将平衡和稳健性分开评估的。因此,本研究测试了 2019 年标准化为 ISO 21268-3 的上流式渗滤测试中的局部平衡假设,并讨论了测试结果的相似性与平衡程度之间的关系。因此,我们总共进行了约 6000 次不同浸出参数的数值模拟,以确定测试标准所研究物质的突破曲线(BTC)。结果表明,标准测试中接触时间最长和最短条件下的两条突破曲线在很大的参数范围内是相同的,这证明了标准测试的稳健性。有趣的是,在平衡或接近平衡和非平衡沥滤条件下会出现相同的 BTC。这一发现表明,有必要重新考虑传统的解释,即当不同接触时间条件下的测试结果看起来相同时,就已经达到了平衡,并鼓励人们努力开发验证平衡沥滤的程序。
Insight into the relationship between similarity and the degree of equilibrium of contaminant release curves through numerical simulations
The assumption of local equilibrium, especially in test standards for assessing the leaching of hazardous substances from materials, is crucial for the use of test results and the robustness of testing. However, previous studies of contact time conditions in percolation test standard have evaluated equilibrium and robustness separately. Therefore, this study tests the assumption of local equilibrium in the up-flow percolation test, standardized as ISO 21268-3 in 2019, and discusses the relationship between the similarity of test results and degree of equilibrium. Thus, we conducted approximately 6000 numerical simulations in total with varying leaching parameters to determine breakthrough curves (BTCs) for the substances investigated by the test standard. The results showed that the two BTCs for the longest and shortest contact time conditions within the standard test were identical over a wide range of parameters, supporting the robustness of the standard test. Interestingly, identical BTCs occur in equilibrium or near-equilibrium and nonequilibrium leaching. This finding indicates the need to reconsider the conventional interpretation that equilibrium is reached when test results with different contact time conditions appear identical and encourages efforts to develop procedures to verify equilibrium leaching.
期刊介绍:
The Journal of Contaminant Hydrology is an international journal publishing scientific articles pertaining to the contamination of subsurface water resources. Emphasis is placed on investigations of the physical, chemical, and biological processes influencing the behavior and fate of organic and inorganic contaminants in the unsaturated (vadose) and saturated (groundwater) zones, as well as at groundwater-surface water interfaces. The ecological impacts of contaminants transported both from and to aquifers are of interest. Articles on contamination of surface water only, without a link to groundwater, are out of the scope. Broad latitude is allowed in identifying contaminants of interest, and include legacy and emerging pollutants, nutrients, nanoparticles, pathogenic microorganisms (e.g., bacteria, viruses, protozoa), microplastics, and various constituents associated with energy production (e.g., methane, carbon dioxide, hydrogen sulfide).
The journal''s scope embraces a wide range of topics including: experimental investigations of contaminant sorption, diffusion, transformation, volatilization and transport in the surface and subsurface; characterization of soil and aquifer properties only as they influence contaminant behavior; development and testing of mathematical models of contaminant behaviour; innovative techniques for restoration of contaminated sites; development of new tools or techniques for monitoring the extent of soil and groundwater contamination; transformation of contaminants in the hyporheic zone; effects of contaminants traversing the hyporheic zone on surface water and groundwater ecosystems; subsurface carbon sequestration and/or turnover; and migration of fluids associated with energy production into groundwater.