Tecnologico de Monterrey, Escuela de Ingeniería y Ciencias, Vía Atlixcáyotl 5718, Reserva Territorial Atlixcáyotl, Puebla, CP 72453, Pue, México.
National Engineering Laboratory for Industrial Wastewater Treatment, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
Environ Sci Pollut Res Int. 2022 Feb;29(6):8746-8757. doi: 10.1007/s11356-021-16221-2. Epub 2021 Sep 7.
The imminent arrival of nanoparticles (NPs) to the wastewater treatment plants (WWTP) brings concern about their effects, which can be related to the wastewater composition. In this work, the effects of titanium dioxide (TiO) NPs in the removal of carbon, nitrogen, and phosphorus by activated sludge bioreactors during the treatment of synthetic, raw, and filtered wastewaters were evaluated. Floc size, compaction of sludge, and morphological interactions between sludge and NPs were also determined. The main effect of TiO NPs was the inhibition of up to 22% in the removal of ammonia nitrogen for all types of wastewaters. This effect is strong dependent on combined factors of TiO NPs concentration and content of organic matter and ammonia in wastewater. The removal of dissolved organic carbon was affected by TiO NPs in lower level (up to 6%) than nitrogen removal for all types of wastewaters. Conversely to adverse effects, the removals of orthophosphate in the presence of TiO NPs were improved by 34%, 16%, and 55% for synthetic, raw, and filtered wastewater, respectively. Compaction of the sludge was also enhanced as the concentrations of NPs increased without alterations in the floc size for all types of wastewaters. Based on TEM and STEM imaging, the main interaction between TiO NPs and the activated sludge flocs was the adsorption of NPs on cell membrane. This means that NPs can be attached to cell membrane during aerobic wastewater treatment, and potentially disrupt this membrane. The effects of TiO NPs on macronutrient removal clearly depended on wastewater characteristics; hence, the use of realistic media is highly encouraged for ecotoxicological experiments involving NPs.
纳米颗粒 (NPs) 即将进入废水处理厂 (WWTP)，这引起了人们对其影响的关注，这些影响可能与废水成分有关。在这项工作中，评估了二氧化钛 (TiO) NPs 在处理合成、原水和过滤废水的活性污泥生物反应器中对碳、氮和磷去除的影响。还确定了絮体大小、污泥压实和污泥与 NPs 之间的形态相互作用。TiO NPs 的主要影响是抑制所有类型废水中氨氮的去除，最高可达 22%。这种影响强烈依赖于 TiO NPs 浓度以及废水中有机物和氨含量的综合因素。与氮去除相比，TiO NPs 对所有类型废水中溶解有机碳的去除影响较小（最高可达 6%）。与不利影响相反，在存在 TiO NPs 的情况下，合成、原水和过滤废水的正磷酸盐去除率分别提高了 34%、16%和 55%。随着 NPs 浓度的增加，污泥的压实程度也得到了提高，而所有类型废水的絮体大小均无变化。基于 TEM 和 STEM 成像，TiO NPs 与活性污泥絮体之间的主要相互作用是 NPs 在细胞膜上的吸附。这意味着 NPs 可以在好氧废水处理过程中附着在细胞膜上，并可能破坏这种膜。TiO NPs 对大量营养素去除的影响显然取决于废水特性；因此，在涉及 NPs 的生态毒理学实验中，强烈鼓励使用实际介质。
