Under the Toxic Substances Control Act (TSCA), the Environmental Protection Agency (EPA) is required to perform new chemical reviews of nanomaterials identified in premanufacture notices. However, environmental fate models developed for traditional contaminants are limited in their ability to simulate nanomaterials’ environmental behavior by incomplete understanding and representation of the processes governing nanomaterial distribution in the environment and by scarce empirical data quantifying the interaction of nanomaterials with environmental surfaces. In this study, the well-known Water Quality Analysis Simulation Program (WASP) was updated to incorporate particle collision rate and particle attachment efficiency to simulate multiwalled carbon nanotube (MWCNT) fate and transport in surface waters. Heteroaggregation attachment efficiencies (α_het) values derived from sediment attachment studies are used to parametrize WASP for simulation of MWCNTs transport in Brier Creek, a coastal plain river located in central eastern Georgia, and a tributary to the Savannah River. Simulations using a constant MWCNT load of 0.1 kg d^–1 in the uppermost Brier Creek water segment showed that MWCNTs were present predominantly in the Brier Creek water column, while downstream MWCNT surface and deep sediment concentrations exhibited a general increase with time and distance from the source, suggesting that MWCNT releases could have increasing ecological impacts in the benthic region over long time frames.

中文翻译：

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使用水质分析模拟程序（WASP）模拟地表水系统中的多壁碳纳米管传输

根据《有毒物质控制法》（TSCA），要求环境保护局（EPA）对制造前通知中标识的纳米材料进行新的化学审查。然而，由于对纳米材料在环境中分布的过程的不完整理解和表示，以及通过量化纳米材料与环境表面相互作用的稀少经验数据，针对传统污染物开发的环境归因模型在模拟纳米材料的环境行为方面的能力受到限制。在这项研究中，更新了著名的水质分析模拟程序（WASP），以结合颗粒碰撞率和颗粒附着效率来模拟多壁碳纳米管（MWCNT）的命运和在地表水中的运输。异种聚集的附着效率（α来自沉积物附着研究的_het）值用于对WASP进行参数化，以模拟在Brier Creek，位于佐治亚州中部的沿海平原河以及萨凡纳河的支流中的MWCNTs传输。在最上方的Brier Creek水段中使用0.1 kg d ^–1的恒定MWCNT负荷进行的模拟显示，MWCNT主要存在于Brier Creek水柱中，而下游MWCNT表面和深层沉积物浓度则随着时间和距离的增加而总体增加。消息来源表明，长期以来，碳纳米管的释放对底栖地区的生态影响可能会增加。