The concentrations of nitrous oxide varies between 57 and 329 nmol/dm3, saturation is 674%～4 134% in the Zhujiang River Estuary. This suggests that the area is an emissive source of nitrous oxide. The acetylene inhib...The concentrations of nitrous oxide varies between 57 and 329 nmol/dm3, saturation is 674%～4 134% in the Zhujiang River Estuary. This suggests that the area is an emissive source of nitrous oxide. The acetylene inhibition technique is employed to evaluate the rates of nitrification, denitrification and nitrate reduction by bacterial activities in the sediments at three sites. The average of nitrification, denitrification and nitrate reduction rates ranges from 0.32 to 2.43, 0.03 to 0.84 and 4.17 to 13.06 mmol/(m2·h), respectively. The ver- tical profiles of the sediments show that the nitrification and denitrification processes mainly take place in the depth from 0 to 4 cm and depend on regional conditions. The rates of nitrification, denitrification and nitrate reduction are dominated by Eh, nitrate and ammoni- um concentrations in sediments and DO in overlay water. There is a coupling between nitrification and denitrification.展开更多
基金supported by the Knowledge Innovation Engineering of Chinese Academy of Sciences under contract No.KZCX3-SW-214,KSCX2-SW-132the Natural Science Foundation of Guangdong Province under contract No.032622.
文摘The concentrations of nitrous oxide varies between 57 and 329 nmol/dm3, saturation is 674%～4 134% in the Zhujiang River Estuary. This suggests that the area is an emissive source of nitrous oxide. The acetylene inhibition technique is employed to evaluate the rates of nitrification, denitrification and nitrate reduction by bacterial activities in the sediments at three sites. The average of nitrification, denitrification and nitrate reduction rates ranges from 0.32 to 2.43, 0.03 to 0.84 and 4.17 to 13.06 mmol/(m2·h), respectively. The ver- tical profiles of the sediments show that the nitrification and denitrification processes mainly take place in the depth from 0 to 4 cm and depend on regional conditions. The rates of nitrification, denitrification and nitrate reduction are dominated by Eh, nitrate and ammoni- um concentrations in sediments and DO in overlay water. There is a coupling between nitrification and denitrification.
