摘要
反硝化细菌在人工湿地对N元素去除的过程中发挥着关键作用。为了解湿地类型、基质、植被和水力负荷及物理参数对人工湿地反硝化功能细菌丰度的影响,构建了9个不同工艺组合的人工湿地小试装置。利用实时荧光定量PCR技术检测湿地基质中反硝化功能基因nir S,nir K和nos Z的丰度。结果显示,湿地中nir S,nir K和nos Z丰度(以每ng总DNA中的拷贝数计)分别为4.88×103~2.13×105copies/ng,1.2×101~2.14×103copies/ng和1.98×103~2.09×105copies/ng,其中nir S显著高于nir K丰度,nir S丰度与湿地出水的p H显著正相关。分析湿地4种设计参数对反硝化功能基因丰度的影响程度,结果显示,对nir S丰度影响程度大小依次为湿地类型>植被类型>水力负荷>基质类型,水平潜流和上行垂直流人工湿地中nir S丰度显著高于下行垂直流人工湿地,无植物人工湿地nir S丰度显著高于有植物人工湿地;对nir K丰度影响程度大小依次为湿地类型>植被类型>基质类型>水力负荷,水平潜流人工湿地nir K丰度显著高于下行垂直流湿地;对nos Z丰度影响程度大小依次为湿地类型>水力负荷>植被类型>基质类型,但影响都不显著。
Denitrification bacteria play a key role in the process of nitrogen removal in constructed wetland( CWs). In order to better understand the influence of wetland types,substrate,vegetation and hydraulic loading rate( HLR) on the abundance of denitrifying genes,we conducted 9 different pilot-scale CWs and measured the copy numbers of nir S,nir K and nos Z genes in the CWs using real-time quantitative PCR( q PCR). The results showed that the abundance of nir S,nir K and nos Z genes were 4. 88 × 103~ 2. 13 × 105 copies / ng,1. 2 × 101~ 2. 14× 103 copies / ng and 1. 98 × 103~ 2. 09 × 105 copies / ng,respectively. The abundance of nir S gene was significantly higher than that of nir K gene,and was positively correlated to p H of the effluent in the CWs. The results indicated that the extent of the influence of wetland types,substrate,vegetation and HLR on the abundance of nir S gene was ranked as follows: wetland types > vegetation > HLR > substrate,successively. The abundance of nir S gene in the horizontal flow CWs and the upward vertical flow CWs was significantly higher than that in the downward vertical flow CWs,and nir S gene in the unplanted CWs was significantly more abundant than that in the CWs planted with vegetation. The extent of the influence of four designing factors on nir K gene abundance was ranked as follows: wetland types > vegetation > substrate > HLR,successively. The abundance of nir K gene in the horizontal flow CWs was found significantly higher than that in the upward vertical flow CWs. In terms of nos Z gene,the extent of the influence of four designing factors on its abundance was ranked as follows: wetland types > HLR >vegetation > substrate,successively. However,none of them played a significant role on nos Z gene abundance.
出处
《环境工程学报》
CAS
CSCD
北大核心
2015年第6期2645-2652,共8页
Chinese Journal of Environmental Engineering
基金
国家"十二五"科技支撑计划课题(2012BAJ21B07-04)
国家自然科学基金资助项目(41201506)
