Wen Zhang, Ph.D., P.E., BCEE
Principal Investigator
Professor
Phone: (973) 596-5520
Fax: (973) 596-5790
Email: wen.zhang@njit.edu
Office Location: Colton Hall 211
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Dr. Zhang’s group published a paper in Water Research on removing algogenic odorous micropollutants using nanobubble-enabled foam fractionation.
The presented study evaluated the nanobubble-driven foaming processes and the use of the enabled foam fractionation for the removal of odorous compounds from water. To simulate foaming, one cationic and one anionic surfactant (CTAB and SDS) were compared. The cationic surfactant CTAB yielded greater foaming ability as indicated by the higher foam volume compared to SDS. A low pH and high ionic strength and high surfactant concentrations generally improved the foam stability as described above and also enhanced the removal of geosmin and 2-MIB to different extent. At the same surfactant concentration, CTAB led to the removal rates of geosmin and 2-MIB at 85% and 58%, respectively, within 60 minutes, much greater than those (74% and 48%, respectively) obtained by SDS, because CTAB has longer hydrophobic alkyl chains and elicits a stronger attraction with hydrophobic odor compounds. The removal kinetics for nanobubble-enabled foam fractionation was increased by about 5-6 times compared to that for microbubble-enabled foam fractionation. The optimized foam fractionation operation was subsequently applied to treat real lake water with spiked odorous compounds, which reveals the removal performance was not affected the lake water matrixes such as turbidity or natural organic matter and thus highlight the promising practical values of nanobubble-driven foam fractionation in micropollutant mitigation from impaired water. Implementing nanobubble-enabled foam fractionation can lead to significant environmental and health benefits. This study provides a foundation for promoting the application of foam fractionation in real-world scenarios by integrating it into existing water treatment systems as a complementary process to enhance the removal of algogenic micropollutants, particularly during harmful algal blooms (HABs). However, further research is necessary to advance practical applications. For instance, it is crucial to evaluate and mitigate the presence of residual surfactants, such as CTAB, following foam fractionation. This could be achieved through additional treatments like GAC adsorption or coagulation to ensure drinking water safety and minimize human exposure. Additionally, exploring environmentally friendly alternative foaming agents beyond those currently used could further optimize the process. By addressing these challenges, our research contributes to the advancement of sustainable water management practices. This project was funded by a subaward of the NOAA Prevention, Control and Mitigation of HABs (PCMHAB) award (NA22NOS4780172) to the University of Maryland Center for Environmental Studies (UMCES) through the US HAB Control Technologies Incubator (US HAB-CTI), a partnership between the National Oceanic and Atmospheric Administration (NOAA), UMCES and Mote Marine Laboratory.
成果简介
近日，新泽西理工大学张文团队博士生章逸寒在Water Research上发表了题为“Nanobubble-enabled foam fractionation to remove algogenic odorous micropollutants”的研究论文。该研究利用空气纳米气泡产生的泡沫分馏技术，搭配两种常见的表面活性剂CTAB和SDS, 实现了从废水中去除和富集两种常见的臭味化合物——1-乙基-4-异丙基环己醇（geosmin）和2-甲基异丁醇（2-MIB）。本研究评估了纳米气泡驱动的发泡过程以及使用泡沫分馏去除水中气味化合物的方法，比较了阳离子表面活性剂（CTAB）和阴离子表面活性剂（SDS）。结果显示，阳离子表面活性剂 CTAB 的发泡能力强于 SDS，表现为泡沫体积更大。低 pH 值、高离子强度和高表面活性剂浓度通常能改善泡沫的稳定性，并且不同程度地提高了对geosmin和 2-MIB 的去除率。在相同表面活性剂浓度下，CTAB 在 60 分钟内对geosmin和 2-MIB 的去除率分别为 85% 和 58%，显著高于 SDS 的去除率（分别为 74% 和 48%）。这归因于 CTAB 具有较长的疏水烷基链，对疏水性气味化合物有更强的吸引力。与微气泡泡沫分离相比，纳米气泡泡沫分离的去除动力学提高了约 5-6 倍。优化后的泡沫分离操作随后应用于额外添加了气味化合物的真实湖水，结果表明去除效果不受湖水基质（如浊度或天然有机物）的影响，凸显了纳米气泡驱动的泡沫分离在污染水体中去除微污染物方面的实际应用价值。实施纳米气泡泡沫分离可以带来显著的环境和健康效益，本研究为将泡沫分离技术应用于现实场景奠定了基础，并将其作为一种补充工艺，整合到现有水处理系统中，以增强对藻类微污染物的去除效果，特别是在有害藻华（HAB）期间。然而，还需要进一步研究以推进该技术的实际应用。例如，评估并减轻泡沫分离后残留表面活性剂（如 CTAB）的存在至关重要。可通过 GAC 吸附或凝聚等附加处理方法来确保饮用水安全并将人体接触降至最低。此外，探索当前使用的发泡剂之外的环保替代品，亦能进一步优化工艺。通过应对这些挑战，我们的研究有助于推动可持续水管理实践的发展。这项研究得到了美国国家海洋和大气管理局 (NOAA) 防治和缓解有害藻华 (PCMHAB) 资助 (NA22NOS4780172)。
第一作者：章逸寒
通讯作者：张文
通讯单位：新泽西理工大学
文章链接: https://www.sciencedirect.com/science/article/pii/S0043135424014398?dgcid=author
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