Particulate matter (PM, especially PM_2.5 with diameter 2.5 microns) has been regarded as the major air pollutant. Negative air ions (NAIs) could electrically charge PM and remove it much more efficiently. In this study, a bio‐generator of NAIs has been developed, which helps plants to generate NAIs at around 100 × 10⁶ ions/cm³ under pulsed electrical field (PEF) treatment. By using the bio‐generator, PM_2.5 concentration in a growth chamber could be reduced from around 500 to near 0 µg/m³ within 5 minutes. It could also be used to remove continuously generated PM. Upon PEF treatment, genes encoding oxidoreductases and other enzymes were up‐regulated, some of which might contribute to the generation of superoxide anions (one of NAIs). On the other hand, the emission of large numbers of electrons from the surface/edge of plant leaves has been detected upon PEF treatment and these electrons might be captured by surrounding air molecules to generate high concentration of NAIs.

中文翻译：

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基于植物的空气负离子释放系统及其在颗粒物去除中的应用

颗粒物（PM，尤其是直径为 2.5 微米的PM _2.5）已被视为主要的空气污染物。负空气离子 (NAI) 可以使 PM 带电并更有效地去除它。在这项研究中，开发了一种 NAI 生物发生器，它可以帮助植物在脉冲电场 (PEF) 处理下以大约 100 × 10 ⁶离子/cm ³产生 NAI 。通过使用生物发生器，生长室中PM _{2.5 的}浓度可以从大约 500 降低到接近 0 µg/m ³5 分钟内。它还可用于去除连续产生的 PM。PEF 处理后，编码氧化还原酶和其他酶的基因被上调，其中一些可能有助于产生超氧阴离子（NAI 之一）。另一方面，在 PEF 处理时检测到植物叶片表面/边缘的大量电子发射，这些电子可能被周围的空气分子捕获以产生高浓度的 NAI。