Nanosystems Engineering Research Center for Nanotechnology-Enabled Water Treatment, School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ 85287-3005, USA.
NASA Johnson Space Center, Houston 77058, TX, United States.
J Colloid Interface Sci. 2022 Feb;607(Pt 1):720-728. doi: 10.1016/j.jcis.2021.09.033. Epub 2021 Sep 8.
Carbon dioxide nanobubbles can increase effective gas-transfer to solution and enhance buffering capacity given the stable suspension in water of CO gas within nanobubbles and the existence of larger gas/water interface.
The physico-chemical properties and responses of CO nanobubbles were recorded at different generation times (10, 30, 50, and 70 min) and benchmarked against traditional macrobubbles of CO for the same amount of delivered gas. Effective concentration of CO was evaluated by measuring the buffer capacity (β). The size distribution of nanobubbles during the experiments was measured by Nanoparticle Track Analysis.
The mass transfer coefficient (Ka) showed a dramatically increase by 11-fold for the same volume of gas delivered when using nanobubbles. The β values obtained for nanobubbles were 7 times higher than that of traditional bubbles which can lead to significant source of CO availability by using the nanobubble method. Nanobubbles, consequently, undergo mass loss at higher pH corresponding to mass transfer process due to concentration gradient at the surrounding nanobubbles. This is the first report of CO nanobubbles buffer capacity evaluation.
二氧化碳纳米气泡可以增加有效气体转移到溶液中，并增强缓冲能力，因为 CO 气体在纳米气泡中的稳定悬浮和更大的气/水界面的存在。
在不同的生成时间（10、30、50 和 70 分钟）下记录 CO 纳米气泡的物理化学性质和响应，并与相同输送气量的传统 CO 大气泡进行基准比较。通过测量缓冲能力（β）来评估 CO 的有效浓度。在实验过程中，通过纳米颗粒跟踪分析测量纳米气泡的尺寸分布。
当使用纳米气泡时，相同体积的气体传递的传质系数（Ka）增加了 11 倍。纳米气泡获得的β值比传统气泡高 7 倍，这可以通过使用纳米气泡方法显著提高 CO 的可用性来源。由于周围纳米气泡的浓度梯度，纳米气泡在较高的 pH 值下会经历质量损失，这对应于传质过程。这是首次报道 CO 纳米气泡缓冲能力的评估。
