College of Resources and Environment, Southwest University, Beibei, Chongqing, 400715, China.
College of Resources and Environment, Southwest University, Beibei, Chongqing, 400715, China; Lamjung Campus, Institute of Agriculture and Animal Science, Tribhuvan University, Kathmandu, Nepal.
Sci Total Environ. 2024 Nov 1;949:174975. doi: 10.1016/j.scitotenv.2024.174975. Epub 2024 Jul 23.
Nitrogen oxides (NO) emissions can cause air pollution that is harmful to human health, even producing serious ecological problems. Whether it is diluted in the air or not, the management and valorization of NO from industrial emissions have been constrained by technology and finance. This study shows that red soil can be used as a photocatalyst to convert NO into soil nitrate nitrogen (NO-N) in the soil. The addition of zinc oxide (ZnO) and titanium dioxide (TiO) onto the soil surface improves the photocatalytic precipitation efficiency of 1 ppm NO, approaching a removal efficiency of 77 % under ultraviolet (UV) light. The efficiency of red soil in precipitating NO through adsorption exceeded that of photocatalysis at 100 ppm NO (e.g. 16.02 % versus 7.70 % in 0.1-mm soil). Pot experiment reveals that the precipitated NO-N promoted biomass of water spinach (Ipomoea aquatica Forsk). Additionally, adding ZnO or TiO also affects mineral nutrition. This demonstration of converting air pollutants into available nitrogen (N) for plant growth not only provides a new perspective on treatment and valorization for NO but also sheds light on the transport of N in the air-soil-plant path.
氮氧化物（NO）排放会导致空气污染，危害人类健康，甚至产生严重的生态问题。无论是在空气中被稀释，还是不被稀释，工业排放的 NO 的管理和利用都受到技术和资金的限制。本研究表明，红壤可用作光催化剂，将空气中的 NO 转化为土壤中的硝酸盐氮（NO-N）。在土壤表面添加氧化锌（ZnO）和二氧化钛（TiO）可提高 1ppmNO 的光催化沉淀效率，在紫外（UV）光下接近 77%的去除效率。在 100ppmNO 下，红土通过吸附沉淀 NO 的效率超过光催化（例如，在 0.1mm 土壤中分别为 16.02%和 7.70%）。盆栽实验表明，沉淀的 NO-N 促进了水蕹菜（Ipomoea aquatica Forsk）的生物量。此外，添加 ZnO 或 TiO 也会影响矿质营养。将空气污染物转化为可用于植物生长的有效氮（N），不仅为 NO 的处理和利用提供了新视角，也为空气-土壤-植物路径中 N 的迁移提供了思路。
