REN Mingcheng1, WANG Dongqi1, HU Beibei2, CHEN Zhenlou1

(1.School of Geographic Sciences, East China Normal University, Shanghai 200241, China;
2.College of Urban and Environmental Sciences, Tianjin Normal University, Tianjin 300387, China; )

Abstract: Acetylene inhibition method was used to measure denitrification rate, potential and their seasonal changes (March and August) in three typical river sediments, which are NY ( Nanyun in downtown), BT (Beitang sewage-received river) and natural river DL (in suburban), and they have different pollution characteristics. Results show that (1)denitrification rates of Tianjin river sediments with different pollution characteristics have significant spatial differences (p<0.05) between summer and winter. Denitrification rate of the sewage-received river sediment is significantly higher than other two rivers in summer, but on the contrary, the lowest in winter; (2)based on the full year data, sediment denitrification rates in each river in summer are higher than winter, and Beitang sewage-received river shows the greatest seasonal variation; (3)Beitangsewage-received rive sediment has higher denitrification potential compared with other two rivers; and (4)denitrification rate and potential decrease with increasing depth of the sediment in three rivers. By using factors correlation analysis, sediment organic carbon, in different types of rivers in Tianjin, may be a significant factor influencing denitrification process, leading to variations in seasons and space. Sediment denitrification rate has a significant positive correlation (p<0.05) with sediment organic carbon. Denitrification potential is 1.50 to 22.8 times higher than denitrification rate in sediment, and denitrification potential in the sewage-received river sediment is higher compared with other clean rivers.

Key words: denitrification rate; denitrification potential

EARTH AND ENVIRONMENT Vol.44, No.5 Tot No.313, 2016, Page 527-533