山西省农业水生态系统重金属污染实证研究——以汾河沉积物为研究对象

STUDY ON THE POLLUTION OF HEAVY METALS IN AGRICULTURE AQUATIC ECOSYSTEM——TAKING SHANXI AS AN EXAMPLE

关键词:  水生态 迁移 转化规律 山西

Key words:  water ecology  migration  transformation law  Shanxi

摘要:

［目的］通过分析山西的汾河临汾段、太原市滨河湿地公园沉积物中重金属迁移转化规律，以期为山西生态农业中水生态系统的修复提供数据支持。［方法］对山西的汾河临汾段、太原市滨河湿地公园进行野外采样，试样分别进行好氧、厌氧、高度厌氧、好氧后厌氧等4个方式的培养处理，在室内设置试验所需的氧化还原环境，对比沉积物中重金属赋存形态，对经植被恢复后沉积物、未经植被恢复沉积物进行培养。模拟水生植物生长根际氧化状态，水生植物生长周期，研究山西省农业水生态系统的迁移转化规律。［结果］在不同处理条件下，沉积物迁移转化存在差异，其中好氧处理下汾河沉积物上清液含量呈现出先减小后增加的趋势，在培养过程中，上清液的Zn2+ 含量比高度厌氧、厌氧处理的要高，与汾河相比较，在前16d，湿地公园上清液Zn2+ 浓度变化幅度较小，汾河上清液Zn2+ 浓度降低趋势显著； 经厌氧处理的湿地公园和汾河的Fe2+ 浓度则在后16d呈现快速增加趋势，好氧、高度厌氧的Fe2+ 浓度变化趋势则比较稳定。在中度氧化还原环境中，Fe的释放更容易进行； 在还原条件中，沉积物中可氧化态、可还原态Zn表现的是转移，不是释放，上清液中Zn2+ 来自弱酸提取态的释放。［结论］利用微生物修复法、植物修复法对汾河水生态系统重金属污染治理，效果显著。

Abstract:

Through the analysis of migration regularity of heavy metals in Fen river of Shanxiand Binhe wetland park of Taiyuan, this paper aimed to provide data supportfor the water ecosystem repair ofecological agriculture in Shanxi.Through the field sampling inFen river and wetland park in Taiyuan, andthe cultivation ofthe samples under the 4 treatments ofaerobic, anaerobic,highly anaerobic, and anaerobic aerobic, the chemical speciation of heavy metals in sediments werecompared, and the growth cycle of aquatic plants was simulated.Then, the migration and transformation of water ecosystem in Shanxi ecological agriculture were studied. The results showed that under different treatment conditions, sediment migration in the aerobic treatments showed a trend of first increase and then decrease, the Zn2+ content of the supernatant was higherin anaerobic and anaerobic treatment.Compared with the Fenhe river, the supernatant Zn2+ concentration in wetland park changed more significantly.The Fe2+ concentration in the anaerobic treatment of Fenhe river and wetland parkshowed a rapid increase trend. In the moderate redox environment, the Fe2+releasedmore easily; In reduction condition, the oxidation and reductionstate ofZnin sediments showed a transfer but not a release. Zn2+ in the supernatant fluid was from the release of weak acid extraction condition. It concluded that the effect was remarkableto govern the heavy metal pollutionin water ecological system by using microbial remediation and phytoremediation