Zhang Ning, Yang Yixiao, Huang Lihua, Xie Huijun, Hu Zhen
Environment Research Institute, Shandong University Jinan 250100 China
School of Resources and Environment, Linyi University Linyi Shandong 276005 China.
RSC Adv. 2019 Nov 4;9(62):35931-35938. doi: 10.1039/c9ra07364g.
At low temperature, plants wither and microbial activities decrease, leading to a decline in the pollutant-treatment performance of constructed wetlands (CWs). In this study, vertical flow CWs (VFCWs) with birnessite (Mn oxides)-coated sand (Mn-CWs) were developed to investigate the pollutant removal performance and mechanism in a cold climate. The results showed that the average removal efficiencies for NH-N, NO-N, TN, and TP were 73.81%, 90.66%, 82.44%, and 57.89% in Mn-CWs, respectively, while the average removal efficiencies for NH-N, NO-N, TN, and TP were 29.07%, 90.40%, 62.80%, and 26.32% in the control, respectively. Mn-CWs enhanced microbial denitrification and matrix storage, as well as inhibited P release in Mn-CWs at low temperature. According to GC-MS analysis of the organic compounds, the Mn-CWs matrix contained much more short-chain volatile organic compounds, such as carboxylic acid derivatives, while the control matrix had more ethyl acetate. The absolute quantities of bacterial 16S rRNA, , , , and were significantly higher than the control at 20 cm height from the bottom ( > 0.05). Illumina high-throughput sequencing analysis revealed that the relative abundances of nitrifying and denitrifying bacteria were both higher in Mn-CWs than that of the control. CWs filled with birnessite-coated sand represent an innovative approach for improving nutrient removal performance in cold climates through chemical absorption and microbial transformation.
在低温下，植物会枯萎，微生物活动会减少，导致人工湿地（CWs）的污染物处理性能下降。在本研究中，开发了具有水钠锰矿（锰氧化物）包覆砂的垂直流人工湿地（VFCWs，即Mn-CWs），以研究寒冷气候下的污染物去除性能及机制。结果表明，Mn-CWs中NH-N、NO-N、TN和TP的平均去除效率分别为73.81%、90.66%、82.44%和57.89%，而对照中NH-N、NO-N、TN和TP的平均去除效率分别为29.07%、90.40%、62.80%和26.32%。Mn-CWs增强了微生物反硝化作用和基质储存，并且在低温下抑制了Mn-CWs中磷的释放。根据对有机化合物的气相色谱-质谱分析，Mn-CWs基质含有更多的短链挥发性有机化合物，如羧酸衍生物，而对照基质中乙酸乙酯更多。在距底部20 cm高度处，细菌16S rRNA、、、和的绝对数量显著高于对照（>0.05）。Illumina高通量测序分析表明，Mn-CWs中硝化细菌和反硝化细菌的相对丰度均高于对照。填充有水钠锰矿包覆砂的人工湿地是一种通过化学吸附和微生物转化来提高寒冷气候下养分去除性能的创新方法。
