|
| Effects of polycyclic aromatic hydrocarbon(phenanthrene)addition on soil nitrogen mineralization processes in rural and urban river wetlands of the Pearl River Estuary, China |
| Received:December 07, 2018 |
| View Full Text View/Add Comment Download reader |
| KeyWord:estuarine wetlands;phenanthrene;nitrogen mineralization;urease activity;ammonia oxidizing microorganism |
| Author Name | Affiliation | E-mail | | YIN Shuo | State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China | | | BAI Jun-hong | State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China | junhongbai@163.com | | WEN Xiao-jun | State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China | | | ZHANG Guang-liang | State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China | | | HAN Ling | State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China | | | HU Xing-yun | State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China | |
|
| Hits: 2145 |
| Download times: 1856 |
| Abstract: |
| Soil samples were collected from rural and urban river wetlands in the Panyu district of the Pearl River Estuary to investigate the effect of polycyclic aromatic hydrocarbon (phenanthrene) addition on soil nitrogen mineralization processes in both types of wetlands. To analyze the changes in nitrogen mineralization rates, urease activities and the ratios of ammonia-oxidizing archaea (AOA) to ammonia-oxidizing bacteria (AOB) in the process of nitrogen mineralization in both wetland soils were analyzed under three phenanthrene-addition treatments (0, 15 mg·kg-1, and 100 mg·kg-1) throughout a 42-day laboratory incubation experiment. Soil nitrogen mineralization rates under all treatments ranged from -4.885 mg·kg-1·d-1 to 5.877 mg·kg-1·d-1.The rate of ammonization varied from -3.823 mg·kg-1·d-1 to 4.677 mg·kg-1·d-1, and the rate of nitrification ranged from -4.990 mg·kg-1·d-1 to 5.369 mg·kg-1·d-1. Urease activities declined with increasing incubation time under all three treatments, with the decreasing percentages ranging between 26.1% and 83.4%. The decrease in percentages under phenanthrene addition was significantly lower than those under control conditions (P<0.05), except for rural river wetland soils under high levels of phenanthrene addition (P>0.05). In rural river wetland soils, the proportion of AOB of ammoxidation microbials under no phenanthrene addition and high levels of phenanthrene addition decreased by 25.85% and 7.31%, respectively, while the proportion increased by 36.37% under low levels of phenanthrene addition. Comparatively less effect was observed in the urban river wetland soils. Phenanthrene is not conducive to nitrogen mineralization except for the improvements observed with high levels of phenanthrene addition to urban river wetland soils. Compared with the control treatment, phenanthrene was beneficial in enhancing urease activities, while no significant effect in rural river wetland soils under high levels of phenanthrene addition was observed. In rural river wetland soils, AOB exhibited higher adaption to phenanthrene, showing the highest adaptability to low concentrations of phenanthrene, while phenanthrene had little effect on the microbial community structure of ammonia oxidation microorganisms in urban river wetlands. |
|
|
|
