黑藻叶、茎腐解释放溶解性有机物的特性

摘要

The characteristics of DOM in the decomposed process of Hydrilla verticillata's leaf and stem were studied by the combination of three-demensional fluorescence spectrum (3DEEM) and ultraviolet-visible (UV-vis) with parallel analysis (PARAFAC). And the effect mechanism of aquatic plants decomposition on the water was further revealed. The results showed that the leaf decomposed quicker than the stem and released more TN and TP. Drying treatment of stem and leaf slowed the release of their TN (P<0.05) while it had no obvious influence on the TP (P>0.05). One protein-like component C1and two components (C2 and C3) in the leaf, two protein-like components (C1 and C3) and two humic-like components (C2 and C4) in the stem were identified by PARAFAC. In the beginning of decomposition (0~40d), the protein-like substances were dominant and the ratio of it in leaf and stem was 1:1.5, and the content of DO in water was low, but the concentration of DOC and NH3-N rised. During 40~60d, both components were present. At the end of decomposition (60~90d), the humic-like acids had a high proportion, the ratio of content in leaf and stem was 1:1, and the value of CDC, TN and PO4-P increased, DOM in the decomposed process of submerged plants may affect the value of DO and pH in water.%通过三维荧光光谱(3DEEM)和紫外吸收光谱(UV-vis)技术结合平行因子分析法(PARAFAC),研究了沉水植物黑藻死亡过程中叶、茎腐解释放DOM的特性,进一步揭示草型湖泊中水生植物腐解对水体的影响机制.结果表明,黑藻叶比茎腐解地更快,释放出更多的TN、TP,烘干处理减缓了叶和茎中 TN 的释放(P<0.05),对 TP 的释放无明显影响(P>0.05).采用平行因子分析法鉴别出叶中含有1种类蛋白质组分C1和2种类腐殖酸组分C2、C3,茎中含有2种类蛋白质C1、C3及2种类腐殖酸组分C2、C4.腐解前期(0~40d)DOM中类蛋白物质占主导地位,且叶与茎中类蛋白质含量比值约为1:1.5,此时水中DO偏低,DOC和NH3-N含量升高,腐解中期(40~60d)类蛋白和类腐殖酸组分共同作用,腐解后期(60~90d)以类腐殖质为主,且叶与茎中类腐殖质含量比值约为1:1,此时电导率、TN和PO4-P含量明显升高,腐解释放DOM可能影响水体的DO和pH值.