底泥微生物活性对蓝藻水华水柱及沉积物间隙水氮磷分布的影响

Microbe activities in the sediment and its influences on N、P distribution of algae bloom water column and interstitial waters

比较研究了蓝藻水华暴发水体与无蓝藻水华暴发水体的沉积物间隙水NH_4^+-N、NO_3^--N和。PO_4^(3-)-P的垂向分布特征和表层沉积物的微生物活性(FDA)、碱性磷酸酶活性(APA),并对它们的相互关系进行了统计分析。结果表明,NH_4^+-N含量在两类水体中,都呈现出表层水<底层水<间隙水的趋势,表明其有从沉积物向上覆水体扩散的风险;而PO_4^(3-)-P、NO_3^+-N浓度则呈现表层水>底层水>间隙水的趋势;沉积物有机质(LOI)、APA和FDA活性也都随着深度增加而逐渐降低。APA与FDA活性之间相关性极显著,暗示碱性磷酸酶的分泌主要受微生物活性的影响。间隙水NH_4^+-N含量与表层10 cm内底泥的APA和FDA活性具有极显著正相关性(a=0.01),表明在厌氧环境中,微生物对氮素的分解和矿化作用主要受二者活性影响。

Sediments from ponds with and without algal blooms were sampled for a comparison study, and the vertical distribution of NH4＋-N, NO3-N and＇PO43-P within the interstitial water were analyzed, as well as the microbial activity （FDA） and alkaline phosphatase （APA） in surface sediments. The results showed the concentration of NHa＊-N increased from superficial waters to interstitial waters in both types of sediments, indicating a risk of NH4＋-N releasing from interstitial waters. However, the concentrations of NO3-N and POn3-P decreased. The decreasing trend was observed for organic matter content （reflected by Loss-on-Ignition, LOI）, FDA activity, and APA in the top 10 cm sediments. Correlation analyses showed that the concentration of NH4＋-N in interstitial waters was-positively correlated with the activities of FDA and APA in surface sediments （0-10 cm）, suggesting that the effect of microbe on N decomposition and mineralization was mainly influenced by the activities of APA and FDA in an anaerobic environment.