沙颍河温室气体含量及沉积物对其贡献

Preliminary Study on Greenhouse Gas Content in Shaying River and the Contribution of Sediment

通过现场采样及沉积柱的现场培养,研究了碳氮污染严重的沙颍河表层水体二氧化碳、甲烷和氧化亚氮浓度及沉积物对温室气体的贡献率。结果表明：沙颍河水体溶存CO2、CH4和N2O的浓度分别398.8~1 052.2、0.263 5~4.020 5、0.013 1~0.070 3μmol/L,在世界范围内,沙颍河CO2、N2O浓度处于中上等水平,CH4处于较高的浓度水平;昼夜变化显示,CO2昼间浓度显著低于夜间的,CH4和N2O昼夜浓度差异性不显著;CO2浓度受水体理化因子影响较小,CH4浓度主要受DO的影响,N2O浓度受DO和TN影响显著;沉积物对水体溶存CO2和N2O的贡献率分别为16.52%和9.40%,表明除沉积物外,沙颍河水体CO2和N2O还有其他重要来源,沉积物对水体溶存CH4的贡献率高达78.83%,是沙颍河溶存CH4的主要来源。

Measurements and an in-situ incubation and was conducted in Shaying River, in which nitrogen pollution was serious and organiccarbon was high. The results show that the concentrations of CO2 , CH4 and N2O are 398.8-1052.2, 0.2635 -4.0205 and 0.0131 -0.0703 pmoL/L respectively. Comparing to the greenhouse gas content in other rivers in the world, the CO2 and N2O concentration in Shaying River belong to above average level, CH4 concentration is at a higher level. Diel variations show th a t, CO2 content in the daytime is significant lower than that at night, while the content of CH4 and N2O demonstrates no differences between that in the daytime and at night. Theenvironmental factors have no apparent effect to the CO2 concentration; while the CH4 concentration is mainly controlled by DO. N2O concentration in Shaying River is mainly effected by DO and TN. Sediment is an important source to CO2 and N2O , but its contribution ratio to CO2 and N2O is 16.52% and 9.40% respectively, which demonstrates that there are other important sources to CO2 and N2O in Shaying River; while the sediment is the main source of CH4 and its contribution is 78.83%.