【摘要】 矮慈姑（Sagittaria pygmaea Miq）是常见的稻田杂草类沉水植物,但在水污染防治中较少被研究应用.本研究利用典型黑臭河道中厌氧还原态的底泥模拟构建污染水体,考察矮慈姑在其中的生长情况和主要污染物的变化.结果表明,矮慈姑及其根系对底泥具有非常强的耐受性,经过180 d的生长,其植株数量扩增了20倍以上,生物量（干重）达到（411.09±136.19）g·m^-2,不但地上部分形成了对底泥密集覆盖的沉水植被层,而且地下部分在底泥中也形成了发达的根系.对矮慈姑根与茎叶生物量进行对比分析发现,矮慈姑的根冠比高达0.66±0.36,远高于其它沉水植物,表明矮慈姑的根可以抵御底泥中还原态物质的胁迫作用,从而发育出较庞大的根系.矮慈姑生长使得底泥中还原性物质浓度大幅下降,相较初始底泥,矮慈姑根系到达的底泥区域中典型还原物质亚铁（Fe（Ⅱ））和酸挥发性硫化物（AVS）分别下降了92.6%和96.3%.此外,矮慈姑生长也较好地阻控了底泥中氮、磷向上覆水释放,使得上覆水氮、磷维持在较低的浓度范围.上述研究结果首次发现,矮慈姑能够很好地耐受重污染水体中厌氧还原态的底泥并可对其中的主要污染物进行去除,在黑臭河道等重污染水体的生态修复中具有很大的应用潜力,可以作为沉水植被修复的先锋种,是值得进一步开发的野生水生植物资源.更多还原

【Abstract】 Sagittaria pygmaea Miq is a common macrophyte submerged in paddy fields, yet it has been seldomly studied or applied in water pollution control. This study investigated the growth of Sagittaria pygmaea Miq along with the change of major pollutants in a simulative polluted water body, which was constructed using the anaerobic sediments obtained from atypical black and odorous river. Results showed that Sagittaria pygmaea Miq, especially its root system, has strong tolerance to contaminated sediments. After 180 days of growth, the plant number has increased over 20 times and the biomass（dry weight） has reached（411.09 ±136.19） g·m^-2.A dense submerged vegetation layer has formed above-ground covering the sediments, and a developed root system was found in the sediments below ground. A comparative analysis on the biomass of root and leave for Sagittaria pygmaea Miq revealed that the root to shoot ratio has reached 0.66±0.36, which was far greater than that of other submerged plants. It indicated the capability of Sagittaria pygmaea Miq to resist the stress from reducing substances in sediments and to develop huge root systems under such circumstances. The growth of Sagittaria pygmaea Miq could significantly reduce the concentrations of reducing substances in sediments. For instance, compared with the initial state, typical reducing substances such as Fe（II） and acidic volatile sulfide（AVS） were lowered by 92.6% and 96.3%, respectively, in sediments reachable by the root system. Meanwhile, the growth of Sagittaria pygmaea Miq also controlled the emission of nitrogen and phosphorus from sediments to overlaying water, maintaining their concentrations in relatively low range. Our study demonstrated, for the first time, that Sagittaria pygmaea Miq could well tolerate the anaerobic sediments in heavily polluted water bodies and remove the major pollutants, possessing great potentials for applications in remediation of ecological systems in black and odorous rivers. Sagittaria pygmaea Miq may be applied as a pioneer species for restoration of submerged vegetation and is a wild aquatic resource worthy of further development.更多还原