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

ABSTRACT

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 CH4oxidation in Weihe River in spring. Besides, this study showed that when there was less NO3⁻-N but more NH4⁺-N in river water, CH4and N2O concentrations would be positively correlated, indicating that different nitrogen sources would impact the coupling mechanism of CH4and N2O productions.