Mikkonen A, Li T, Vesala M, Saarenheimo J, Ahonen V, Kärenlampi S, Blande J D, Tiirola M, Tervahauta A
Department of Biological and Environmental Science, University of Jyväskylä, Jyväskylä, Finland.
Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland.
Indoor Air. 2018 May 6. doi: 10.1111/ina.12473.
Botanical air filtration is a promising technology for reducing indoor air contaminants, but the underlying mechanisms need better understanding. Here, we made a set of chamber fumigation experiments of up to 16 weeks of duration, to study the filtration efficiencies for seven volatile organic compounds (VOCs; decane, toluene, 2-ethylhexanol, α-pinene, octane, benzene, and xylene) and to monitor microbial dynamics in simulated green wall systems. Biofiltration functioned on sub-ppm VOC levels without concentration-dependence. Airflow through the growth medium was needed for efficient removal of chemically diverse VOCs, and the use of optimized commercial growth medium further improved the efficiency compared with soil and Leca granules. Experimental green wall simulations using these components were immediately effective, indicating that initial VOC removal was largely abiotic. Golden pothos plants had a small additional positive impact on VOC filtration and bacterial diversity in the green wall system. Proteobacteria dominated the microbiota of rhizosphere and irrigation water. Airborne VOCs shaped the microbial communities, enriching potential VOC-utilizing bacteria (especially Nevskiaceae and Patulibacteraceae) in the irrigation water, where much of the VOC degradation capacity of the biofiltration systems resided. These results clearly show the benefits of active air circulation and optimized growth media in modern green wall systems.
植物空气过滤是一种很有前景的减少室内空气污染物的技术，但其中的潜在机制仍需深入了解。在此，我们进行了一系列长达16周的室内熏蒸实验，以研究对七种挥发性有机化合物（VOCs；癸烷、甲苯、2-乙基己醇、α-蒎烯、辛烷、苯和二甲苯）的过滤效率，并监测模拟绿墙系统中的微生物动态。生物过滤在亚ppm级VOC水平下起作用，且无浓度依赖性。有效去除化学性质各异的VOCs需要气流通过生长介质，与土壤和陶粒相比，使用优化的商业生长介质进一步提高了效率。使用这些组件进行的实验性绿墙模拟立竿见影，表明初始VOC去除主要是非生物性的。绿萝植物对绿墙系统中的VOC过滤和细菌多样性有微小的额外积极影响。变形菌门在根际和灌溉水中的微生物群中占主导地位。空气中的VOCs塑造了微生物群落，在灌溉水中富集了潜在的VOC利用细菌（特别是涅斯捷连科氏菌科和类土杆菌科），生物过滤系统的大部分VOC降解能力都存在于灌溉水中。这些结果清楚地表明了现代绿墙系统中主动空气循环和优化生长介质的益处。
