摘要
人工湿地(CW)在城市径流污染源头控制中发挥重要的作用。采用潮汐流(TFCW)-垂直潜流(VFCW)串联的复合人工湿地工艺(TF-VFCW),以砾石为填料构建人工湿地模型,探究TF-VFCW长期运行下COD_(cr)、NH_(4)^(+)-N、NO_(3)^(-)-N、TN和Cu2+的去除效果以及微生物群落变化对污染物去除效果的影响。结果表明:在80 d的运行中,TF-VFCW对COD、NH_(4)^(+)-N、TN的去除效率逐渐下降,平均去除率分别为62.92%、65.54%、80.83%;系统对NO_(3)^(-)-N的去除率先保持稳定,随后在波动中略有下降,平均去除率为95.27%;对TP的去除效果相对较为稳定,平均去除率为87.64%;对Cu^(2+)的去除率虽有较大波动但总体上呈现上升的趋势,平均去除率为40.22%。TFCW单元的去污能力明显优于VFCW单元。随着时间的推移,TFCW单元在门水平上的优势菌种由Proteobacteria(变形菌门)变为Firmicutes(厚壁菌门);在属水平上,TF-VFCW中主要除氮微生物为Thauera(索氏菌属)、Thiobacillus(硫杆菌属)、Hydrogenophaga(噬氢菌属)、Nitrosospira(亚硝化螺菌属),主要除磷微生物为Pseudomonas(假单胞菌属)、Dechloromonas(脱氯菌属)、Bacillus(芽孢杆菌)等。TFCW的除氮、除磷功能微生物的多样性要明显优于VFCW。温度对除氮、除磷功能微生物的多样性和群落结构影响较大,NH_(4)^(+)-N、NO_(3)^(-)-N、TN的去除效果明显受到温度的影响,而磷的去除受温度影响较小,其主要通过基质吸附和植物吸收。
Constructed wetland(CW) plays an important role in the source control of urban runoff pollution. A CW model(TF-VFCW) was constructed by using tidal flow(TFCW)-vertical flow(VFCW) with gravel as filler to explore the removal efficiency of COD_(cr)、NH_(4)^(+)-N、NO_(3)^(-)-N, TN and Cu^(2+)under long-term operation.Then, the impact of microbial community changes on pollutant removal was discussed. The results showed that:(1) During the 80-day operation, the removal efficiency of CODcr, NH_(4)^(+)-N and TN by TF-VFCW decreased gradually, and the average removal rates were 62.92%, 65.54% and 80.83%, respectively. The removal rate of NO_(3)^(-)-N in the system remained stable at first, then decreased slightly with the fluctuation, the average removal rate was 95.27%, and the average removal rate of TP was relatively stable with an average removal rate of87.64%. Although the removal rate of Cu^(2+)fluctuated greatly, it showed an upward trend on the whole, with an average removal rate of 40.22%. The decontamination ability of TFCW unit was obviously better than that of VFCW unit.(2) With the extension of time, the dominant bacteria of TFCW unit at the phylum level changed from Proteobacteria to Firmicutes;at the genus level, the main nitrogen removal microorganisms in TF-VFCW were Thauera, Thiobacillus, Hydrogenophaga, Nitrosospira. The main phosphorus removal microorganisms included Pseudomonas, Dechloromonas, Bacillus, etc.(3) The diversity of functional microorganisms for nitrogen and phosphorus removal of TFCW was significantly better than that of VFCW. Temperature had a great influence on the diversity and community structure of functional microorganisms for nitrogen and phosphorus removal. The removal efficiency of NH_(4)^(+)-N, NO_(3)^(-)-N and TN was obviously affected by temperature, while the removal of phosphorus was less affected by temperature, which was achieved mainly through substrate and plant absorption.
作者
杨雅峥
孙皓珺
孙镱铭
甄志磊
YANG Yazheng;SUN Haojun;SUN Yiming;ZHEN Zhilei(College of Urban and Rural Construction,Shanxi Agricultural University,Taigu 030801,China)
出处
《环境工程学报》
CAS
CSCD
北大核心
2023年第2期471-484,共14页
Chinese Journal of Environmental Engineering
基金
山西农业大学科技创新基金(2017YJ04,2018002)。
关键词
潮汐流-垂直潜流人工湿地
径流污染
微生物群落
温度
tidal flow-vertical flow constructed wetland
runoff pollution
microbial community
temperature
