闽江口鳝鱼滩芦苇湿地沉积物甲烷产生与氧化潜力对外源物质输入的响应

研究河口湿地沉积物甲烷(CH4)产生和氧化对外源物质输入的响应,对环境保护及温室气体减排具有重要意义.本研究基于室内培养-气相色谱法,探讨了闽江河口半咸水芦苇(Phragmites australis)沼泽湿地沉积物CH4产生与氧化对不同外源物质(底物、电子受体和营养物质)输入的响应.结果表明:CH3OH(500 mg·kg-1)、C3H9N(500 mg·kg-1)和Fe2+(0~500 mg·kg-1)对CH4产生潜力起促进作用(p0.05);NO-3(0~500 mg·kg-1)、NO-2(0~500 mg·kg-1)、Fe3+(50 mg·kg-1)和NH+4(50~500 mg·kg-1)表现为抑制CH4产生潜力(p0.05);而0~50 mg·kg-1的CH3OH和C3H9N、0~500 mg·kg-1的CH3COOH、SO2-4、Mn4+、PO3-4和低剂量的NH+4(0~5 mg·kg-1)对CH4产生的影响不显著(p0.05).实验剂量内(0~500 mg·kg-1),Fe3+和Mn4+的添加可促进CH4氧化(p0.05);CH3COOH、CH3OH、C3H9N、NO-3、NO-2、SO2-4、NH+4和低剂量的PO3-4(0~50 mg·kg-1)对沉积物CH4氧化潜力均有显著的抑制作用(p0.05);而Fe2+对CH4氧化没有显著影响(p0.05).综合分析表明,CH3COOH、CH3OH、C3H9N、NO-3、NO-2、SO2-4、PO3-4、NH+4和Fe2+的输入对沉积物CH4产生和氧化的综合作用为增加CH4排放通量,而Fe3+和Mn4+输入的综合作用则与之相反.

Response of methane production and oxidation potential to exogenous substances in the Phragmites australis marsh sediments of Shanyutan wetland in the Min River estuary

Methane, a powerful greenhouse gas, is both produced and consumed in estuary sediments. Studying the response of methane production and oxidation potential to exogenous substances in estuarine marsh sediments is important to environment protection and greenhouse gas emission reductions. The rates of methane production and oxidation of sediments under the Phragmites australis marsh in the Shanyutan wetland in the Min River estuary were determined using incubation experiment. Different exogenous substances, including substrates, electron acceptors and nutrients, were added to explore the affecting factors of methane production and oxidation potential. High concentration (500 mg · kg^-1) of methyl alcohol and trimethylamine and 0~500 mg · kg^-1 of ferrous ion promoted methane production potential, nitrate (0~500 mg · kg^-1), nitrite (0~500 mg · kg^-1), ferric iron (50 mg · kg^-1) and ammonium (50~500 mg · kg^-1) inhibited methane production potential, while there was no significant influence for methyl alcohol (0~50 mg · kg^-1), trimethylamine (0~50 mg · kg^-1), low concentration of ammonium (0~5 mg · kg^-1) and acetic acid, sulfate, manganese ion and phosphate radical at the concentration of 0~500 mg · kg^-1. Furthermore, 0~500 mg · kg^-1 of ferric iron and manganese ion promoted methane oxidation potential, while methyl alcohol, trimethylamine, nitrate, nitrite, sulfate, ammonium and low concentration of phosphate radical (0~50 mg · kg^-1) inhibited methane oxidation potential. However, various concentrations of ferrous ion didn't make significant difference on methane oxidation potential. Methane emissions will increase as a response of methane production and oxidation potential to acetic acid, methyl alcohol, trimethylamine, phosphate radical, ammonium and ferrous ion, but will mitigate in response to ferric iron and manganese ion.