卫河新乡市区段春季溶解CH4与N2O浓度特征

对卫河新乡市区段春季CH_4与N_2O浓度进行调查分析,初步探讨了城市河流中典型温室气体的溶存量空间变化及其影响因素.结果表明,受到水中污染物质浓度及人类活动影响,春季卫河表层水中CH_4与N_2O浓度处于超饱和状态,饱和度分别为147.59~2 667.85和4.06~188.25.影响市区内N_2O浓度的主要环境因素为NH~+_4-N(P0.01),而新区污水处理厂排水输入显著提高了N_2O的溶存量,说明污染物类型影响温室气体的产生和积累,NH~+_4-N的硝化过程是城市河流N_2O产生的主要来源.逐步回归分析表明CH_4浓度是NH~+_4-N浓度与水温的相关函数,其中CH_4浓度与NH~+_4-N极显著相关(R2=0.70,P0.01),说明春季卫河中NH~+_4-N浓度是影响卫河春季CH_4溶存的关键因素.此外研究结果显示在NO~-_3-N浓度较低并且NH~+_4-N浓度高时水中CH_4与N_2O浓度具有显著正相关关系,表明有效态氮浓度差异影响CH_4与N_2O产生过程的耦合机制.

Characteristics of Dissolved CH4 and N2O Concentrations of Weihe River in Xinxiang Section in Spring

Distributions of CH₄ and N₂O concentrations in Weihe River in Xinxiang City were monitored in spring of 2015, and their influencing factors were discussed. The result showed that CH₄ and N₂O were super-saturated in surface water of Weihe River. The variation ranges of two gases''saturations in the surface water of Weihe River were 147.59-2667.85 (CH₄) and 4.06-188.25 (N₂O). In the urban area, significant correlation existed between N₂O and NH₄⁺-N concentrations (P<0.01), but in the new district, dissolved N₂O concentration showed sharp increase because of the water input from the urban sewage plants, illustrating that the controlling mechanism on N₂O production varied as pollutant characteristics changed. Stepwise regression analysis showed that CH₄ concentrations could be explained by NH₄⁺-N concentrations and water temperature, and CH₄ concentrations in the surface water of Weihe River was significantly correlated with NH₄⁺-N concentrations (R²=0.70, P<0.01), suggesting that NH₄⁺-N was the key factor in regulating the production and assumption of CH₄ oxidation in Weihe River in spring. Besides, this study showed that when there was less NO₃^--N but more NH₄⁺-N in river water, CH₄ and N₂O concentrations would be positively correlated, indicating that different nitrogen sources would impact the coupling mechanism of CH₄ and N₂O productions.