Key Laboratory of Urban Stormwater System and Water Environment (Ministry of Education), Beijing University of Civil Engineering and Architecture, Beijing, People's Republic of China.
Environ Technol. 2024 Apr;45(11):2268-2283. doi: 10.1080/09593330.2023.2172616. Epub 2023 Feb 22.
The effects of different soil properties on hydrology and nitrogen removal were studied in a simulated bioretention system. Soil capacity of permeability and water retention, changes in the soil environment, leachate concentrations at the surface and bottom layers, quantification of N removal from soil, microorganism and plant by N isotope tracer technique, and functional genes abundance at different depths were evaluated. The results showed that shallow root plants, soil compaction, and low organic matter content were not conducive to the infiltration of bioretention systems. In the 72 h experiment, compaction (especially surface compaction) and planting of herbaceous plants (Ophiopogon japonicus) were not beneficial to the removal of TN, TP, and COD. Adding an appropriate amount of organic matter also affects nitrogen and phosphorus removal. In the process of denitrification, the order of the ability to remove nitrogen is soil adsorption > microbial assimilation > plant uptake. The contribution of soil denitrification is affected by soil compaction, compaction location, plant species and organic matter content. The abundance of 16S rRNA, nitrifying, denitrifying and nrfA genes decreased with soil depth. More copies of genes in topsoil were thought to be due to sufficient nutrients, aerobic condition, anaerobic microsites and submerged state. Soil compaction, organic matter content and plant species affected nitrification, denitrification and DNRA gene characteristics.
本研究采用模拟生物滞留系统，研究了不同土壤性质对水文和氮去除的影响。评估了土壤渗透和持水能力、土壤环境变化、表层和底层渗滤液浓度、土壤中氮去除量、氮同位素示踪技术对土壤、微生物和植物的定量去除以及不同深度的功能基因丰度。结果表明，浅根植物、土壤紧实和低有机质含量不利于生物滞留系统的渗透。在 72 h 的实验中，紧实（尤其是表层紧实）和草本植物（沿阶草）的种植不利于 TN、TP 和 COD 的去除。添加适量的有机质也会影响氮磷的去除。在反硝化过程中，氮去除的能力顺序为土壤吸附>微生物同化>植物吸收。土壤反硝化的贡献受土壤紧实度、紧实位置、植物种类和有机质含量的影响。16S rRNA、硝化、反硝化和 nrfA 基因的丰度随土壤深度的增加而降低。表层土壤中更多的基因拷贝被认为是由于充足的养分、好氧条件、厌氧微生境和淹没状态。土壤紧实度、有机质含量和植物种类影响硝化、反硝化和 DNRA 基因特性。
