Anhui Provincial Engineering Laboratory for Rural Water Environment and Resources, School of Civil and Hydraulic Engineering, Hefei University of Technology, Hefei, 230009, China.
State Key Laboratory of Pollution Control & Resources Reuse, School of the Environment, Nanjing University, Nanjing, 210046, China.
Environ Sci Pollut Res Int. 2021 Dec;28(48):69012-69028. doi: 10.1007/s11356-021-15461-6. Epub 2021 Jul 20.
Four subsurface flow constructed wetlands (SFCWs) filled with different substrates including ceramsite, ceramsite+pyrite, ceramsite+ferrous sulfide, and ceramsite+pyrite+ferrous sulfide (labeled as SFCW-S1, SFCW-S2, SFCW-S3, and SFCW-S4) were constructed, and the removal of nitrogen and phosphorus by these SFCWs coupled with intermittent aeration in the front section was discussed. The key findings from different substrate analyses, including nitrification and denitrification rate, enzyme activity, microbial community structure, and the X-ray diffraction, revealed the nitrogen and phosphorus removal mechanism. The results showed that the nitrogen and phosphorus removal efficiency for SFCW-S1 always remained the lowest, and the phosphorus removal efficiency for SFCW-S4 was recorded as the highest one. However, after controlling the dissolved oxygen by intermittent aeration in the front section of SFCWs, the nitrogen and phosphorus removal efficiencies of SFCWs-S2 and S4 became higher than those of SFCW-S1, and SFCW-S3. It was noticed that the pollutants were removed mainly in the front section of the SFCWs. Both precipitation and adsorption on the substrate were the main mechanisms for phosphorus removal. A minute difference of nitrification rate and ammonia monooxygenase activity was observed in the SFCWs' aeration zone. The denitrification rates, nitrate reductase, nitrite reductase, and electron transport system activity for SFCW-S2 and SFCW-S4 were higher than those detected for SFCW-S1 and SFCW-S3 in the non-aerated zone. Proteobacteria was the largest phyla found in the SFCWs. Moreover, Thiobacillus occupied a large proportion found in SFCW-S2, and SFCW-S4, and it played a crucial role in pyrite-driven autotrophic denitrification.
构建了四个地下流人工湿地（SFCWs），分别填充了不同的基质，包括陶粒、陶粒+黄铁矿、陶粒+硫化亚铁和陶粒+黄铁矿+硫化亚铁（分别标记为 SFCW-S1、SFCW-S2、SFCW-S3 和 SFCW-S4），并讨论了这些 SFCWs 与前段间歇性曝气相结合去除氮磷的情况。通过对不同基质的分析，包括硝化和反硝化速率、酶活性、微生物群落结构和 X 射线衍射，得出了氮磷去除的机理。结果表明，SFCW-S1 的氮磷去除效率始终最低，而 SFCW-S4 的磷去除效率最高。然而，通过控制 SFCWs 前段的溶解氧进行间歇性曝气后，SFCW-S2 和 S4 的氮磷去除效率高于 SFCW-S1 和 SFCW-S3。需要注意的是，污染物主要在 SFCWs 的前段被去除。沉淀和基质吸附是磷去除的主要机制。在 SFCWs 的曝气区，硝化速率和氨单加氧酶活性的差异很小。在非曝气区，SFCW-S2 和 SFCW-S4 的反硝化速率、硝酸盐还原酶、亚硝酸盐还原酶和电子传递系统活性均高于 SFCW-S1 和 SFCW-S3。变形菌门是 SFCWs 中最大的门。此外，硫杆菌在 SFCW-S2 和 SFCW-S4 中占据很大比例，在黄铁矿驱动的自养反硝化中起着关键作用。
