Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China.
Sci Total Environ. 2019 Feb 15;651(Pt 1):1451-1456. doi: 10.1016/j.scitotenv.2018.09.220. Epub 2018 Sep 18.
Hazardous outdoor air pollution has severely affected indoor air quality, threatening the health of billions of people. However, existing indoor air purification technologies are unsatisfactory due to some inherent limitations such as poor efficiency, limited target pollutants, the need to frequently replace filters or adsorbents, or the generation of harmful by-products. Here, we studied the effect and mechanism of cryogenic circulation for indoor air purification. Experimental results show that up to 99% of indoor PM from ambient air was removed at -18 °C. The morphological measurements indicate that micrometer-sized particles are formed concomitantly with the reduction of nanometer- or submicron-sized particles, suggesting that condensational growth of fine particles is responsible for the removal. Applying the method to gaseous pollutant purification demonstrates that 98% of NO is condensed and removed from the ambient air at -50 °C, implying that the method would be effective for multiple indoor pollutants with higher boiling points. Cryogenic condensation may provide a principle for continuous indoor air purification via modified air conditioners and humidifiers in cases where health benefits outweigh energy consumption concerns.
危险的室外空气污染严重影响了室内空气质量，威胁着数十亿人的健康。然而，由于一些固有的局限性，如效率低下、目标污染物有限、需要频繁更换过滤器或吸附剂、或产生有害副产品等，现有的室内空气净化技术并不令人满意。在这里，我们研究了低温循环对室内空气净化的效果和机制。实验结果表明，在-18°C 时，高达 99%的环境空气中的室内 PM 被去除。形态测量表明，微米级颗粒与纳米级或亚微米级颗粒的减少同时形成，表明细颗粒的凝结生长是去除的原因。将该方法应用于气态污染物净化表明，在-50°C 时，98%的 NO 从环境空气中被冷凝和去除，这意味着该方法对于沸点更高的多种室内污染物将是有效的。低温冷凝可能为通过改进空调和加湿器进行持续的室内空气净化提供了一个原理，在这种情况下，健康益处超过了对能源消耗的关注。
