| 蓝藻越冬期湖湾沉积物磷吸附特征和释放风险 |
| 摘要点击 1791 全文点击 781 投稿时间：2021-06-12 修订日期：2021-09-14 |
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| 中文关键词 蓝藻 沉积物 磷 释放 微生物 |
| 英文关键词 cyanobacteria sediment phosphorus release microbe |
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| 中文摘要 |
| 越冬过程是蓝藻暴发的前置阶段，该时期沉积物内源磷是蓝藻水华发生的主要磷源之一.在调查藻型湖湾蓝藻越冬两个时期（休眠期和复苏期）水质和沉积物污染物指标的基础上，进一步分析了水平和垂直方向上沉积物磷吸附特征，阐明沉积物磷释放风险及微生物群落结构变化.结果表明，研究区域两个时期湖湾基本为中度富营养水平，并且水质和沉积物氮磷污染较为严重，越冬期叶绿素a含量（Chl-a）仍然处于较高水平.准二级动力学模型和修正后的Langmuir模型能分别较好地描述沉积物对磷的动力学和等温吸附行为，沉积物理论磷最大吸附量（Qmax）呈现：底层>中层>表层的规律，最高可达1.648 mg·g-1，且底层对磷的吸附速率较高，其准二级动力学模型吸附常数达6.292 g·（mg·min）-1，其吸附参数（Qmax、NAP和EPC0）主要受沉积物自身理化性质和湖体营养水平影响.休眠期沉积物主要扮演着磷汇角色，而复苏期部分沉积物扮演着磷源角色，存在较高的内源磷释放的风险.沉积物微生物群落结构分析结果显示，蓝藻休眠期沉积物中微生物多样性高于复苏期，且部分具有解磷功能的微生物门类相对丰度较高. |
| 英文摘要 |
| The overwinter period is the pre-stage of the algal bloom, and the endogenous phosphorus (P) in sediments is one of the main P sources of algal blooms during this period. Based on the investigation of the water quality and sediment pollutants during the overwinter period of cyanobacteria (recruitment period and dormancy period), this study analyzed the P release characteristics of sediments in the horizontal and vertical directions and clarified the P release risk of sediments and the change in microbial community structures. The results showed that the lake bay was moderately eutrophic in the two periods of the study area, and the water quality and sediment nitrogen and P pollution were more serious, and the chlorophyll a content (Chl-a) was still at a high level in the overwinter period. The pseudo-second order model and the modified Langmuir model could respectively describe the P kinetics and sorption isotherm behavior in the sediment. The theoretical maximum P sorption capacities (Qmax) of sediments were bottom layer>middle layer>surface layer, and the highest value was 1.648 mg·g-1 with the highest P sorption rate constant of the pseudo second-order kinetic model of 6.292 g·(mg·min)-1. Additionally, the P adsorption parameters (Qmax, NAP, and EPC0) were mainly affected by the physical and chemical properties of the sediment itself and the nutritional level of the lake bay. The surface sediments from the dormancy period mainly played the role of P sinks, and the part of sediments from the recruitment period played the role of P sources, in which existed the risk of endogenous P release. The analysis of the microbial community structure in sediments indicated that the microbial diversity in the sediments during the dormancy period was higher than that during the recruitment period, and some microbial categories with phosphate-solubilizing function of relative abundance was high. |
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