Tecnologico de Monterrey, Escuela de Ingeniería y Ciencias, Reserva Territorial Atlixcáyotl, Puebla, Pue, CP 72453, Mexico; University of California, Center for Environmental Implications of Nanotechnology, Santa Barbara, CA, 93106, USA.
Bren School of Environmental Science and Management, University of California at Santa Barbara, CA, 93106, USA; University of California, Center for Environmental Implications of Nanotechnology, Santa Barbara, CA, 93106, USA.
Water Res. 2021 Feb 1;189:116603. doi: 10.1016/j.watres.2020.116603. Epub 2020 Nov 6.
Metal-based nanoparticles (NPs) can be found in wastewater streams, which are significant pathways for the release of NPs to the environment. Determination of the NPs concentration in wastewater streams is important for performing appropriate ecotoxicological evaluations. The aim of this work was to determine the incidence of NPs from 13 different elements throughout the wastewater treatment process by using single particle inductively coupled plasma mass spectrometry (spICP-MS). The incidence was determined in samples of the influent, post-primary treatment and effluent of the activated sludge process, as well as in the reclaimed water of a full-scale wastewater treatment plant (WWTP). In addition, concentration of NPs was determined in the waste activated sludge and in the anaerobic digester. The concentration of metal-based NPs in the influent wastewater were between 1,600 and 10,700 ng/L for elements such as Ti, Fe, Ce, Mg, Zn and Cu, while that for Ni, Al, Ag, Au, Co and Cd was below 100 ng/L. Concentrations in reclaimed water ranged between 0.6 and 721 ng/L, ranked as Mg > Ti > Fe > Cu > Ni > Ce > Zn > Mn > Al > Co > Ag > Cd > Au. Results indicated that the activated sludge process and reclaimed water system removed 84-99% of natural and engineered metal-based NPs from influent to reclaimed water, except for Mg, Ni and Cd where the removal ranged from 70 to 78%. The highest concentrations of NPs were found in the waste activated sludge and anaerobic sludge, ranging from 0.5 to 39,900 ng/L. The size distribution of NPs differed in different wastewater streams within the WWTP, resulting in smaller particles in the effluent (20-180 nm) than in the influent (23-233 nm) for most elements. Conversely, NPs were notably larger in the waste activated sludge samples than in the anaerobic sludge or wastewater, since conditions in the secondary treatment lead to precipitation of several metal-based NPs. The incidence of metal-based NPs from 13 elements in wastewater decreased significatively after the conventional wastewater treatment train. However, anaerobic digesters store high NPs concentrations. Hence, the disposal of sludge needs to take this into account to evaluate the risk of the release of NPs to the environment.
金属基纳米粒子（NPs）存在于废水中，这是 NPs 向环境释放的重要途径。测定废水中 NPs 的浓度对于进行适当的生态毒理学评价非常重要。本工作旨在通过使用单颗粒电感耦合等离子体质谱（spICP-MS）测定 13 种不同元素的 NPs 在整个废水处理过程中的出现情况。在活性污泥工艺的进水、一级处理后和出水以及全规模废水处理厂（WWTP）的再生水中测定了 NPs 的出现情况。此外，还测定了废活性污泥和厌氧消化池中的 NPs 浓度。废水中金属基 NPs 的浓度对于 Ti、Fe、Ce、Mg、Zn 和 Cu 等元素在 1600 至 10700ng/L 之间，而 Ni、Al、Ag、Au、Co 和 Cd 的浓度则低于 100ng/L。再生水中的浓度在 0.6 至 721ng/L 之间，排序为 Mg＞Ti＞Fe＞Cu＞Ni＞Ce＞Zn＞Mn＞Al＞Co＞Ag＞Cd＞Au。结果表明，除了 Mg、Ni 和 Cd 的去除率在 70 至 78%之间外，活性污泥工艺和再生水系统将天然和工程金属基 NPs 从进水去除至再生水的 84-99%。NPs 的最高浓度出现在废活性污泥和厌氧污泥中，范围为 0.5 至 39900ng/L。在 WWTP 内的不同废水中，NPs 的粒径分布不同，导致大多数元素的出水中的颗粒比进水中小（20-180nm）。相反，在废活性污泥样品中，NPs 明显大于厌氧污泥或废水，因为二级处理条件导致几种金属基 NPs 的沉淀。经过传统废水处理工艺后，废水中 13 种元素的金属基 NPs 的出现情况显著降低。然而，厌氧消化池储存了高浓度的 NPs。因此，在评估 NPs 向环境释放的风险时，需要考虑到污泥的处置。
