摘要
沉水植物可以有效控制湖泊富营养化,但不同水环境下其周期性衰亡对湖泊生态系统的影响不容忽视。以苦草为研究对象,采用分解网袋法进行为期66 d的室内模拟试验,研究高纯水和底泥悬浮液环境下不同生物量密度的苦草腐解过程及水体氮、磷等营养盐的浓度变化。结果表明:①不同生物量密度(0.1、0.2、0.4 g/L)的苦草腐解过程均可以分为快速淋溶和缓慢分解两个阶段,不同阶段内组间质量损失率存在差异,但总体趋势一致。②高纯水环境下,水体营养盐含量(COD、TP)与生物量呈正相关(相关系数r分别为0.478、0.697,P<0.05),0.4 g/L的苦草会明显提高水中各营养盐含量,破坏水体水质;苦草腐解时,磷的矿化速率比氮快。③底泥悬浮液环境下,苦草残体腐解对水体水质的影响有明显的时效性和阶段差异性,TN浓度与水体中DO浓度、pH值显著相关(r分别为0.839、0.806,P<0.05),苦草腐解释放的氮、磷等营养盐在底泥-水界面发生复杂的吸附和降解反应,适量的苦草残体腐解可促进各形态氮、磷的迁移转化。
Submerged plants can effectively control lake eutrophication,but the effects of their periodic decay on lake ecosystems in different water environments can not be ignored.An indoor decay simulation experiment of Vallisneria natans was carried out for 66 days by using the mesh bag method.The decomposition process and variations in concentration of nitrogen,phosphorus and other nutrients in water under different biomass densities in high purity water and sediment suspension were explored.The decomposition process of Vallisneria natans with different biomass densities(0.1 g/L,0.2 g/L and 0.4 g/L)could be divided into two stages including rapid leaching and slow decomposition,and the mass loss rate of each biomass density group in different stages was different,but the overall trend was consistent.In high purity water environment,the nutrient content(COD,TP)of water was positively correlated with biomass(r=0.478 and 0.697,P<0.05).0.4 g/L of Vallisneria natans would significantly increase the content of nutrients and destroy the water quality.When it was decomposed,the mineralization rate of phosphorus was faster than that of nitrogen.Under the environment of sediment suspension,the effect of decomposition of Vallisneria natans on water quality had obvious timeliness and stage difference.TN concentration was significantly positively correlated with DO and pH(r=0.839 and 0.806,P<0.05).Complex adsorption and degradation reactions of nitrogen,phosphorus and other nutrients released by the decomposition of Vallisneria natans took place at the sediment-water interface,and a proper amount of Vallisneria natans could promote the migration and transformation of nitrogen and phosphorus in various forms.
作者
李旭
崔康平
汤海燕
藕翔
LI Xu;CUI Kang-ping;TANG Hai-yan;OU Xiang(School of Resources and Environmental Engineering,Hefei University of Technology,Hefei 230009,China)
出处
《中国给水排水》
CAS
CSCD
北大核心
2020年第7期60-67,共8页
China Water & Wastewater
基金
安徽省科技重大专项(17030801031)。
关键词
苦草腐解
水质
高纯水
底泥悬浮液
质量损失率
营养盐
decomposition of Vallisneria natans
water quality
high purity water
sediment suspension
mass loss rate
nutrients
