生态沟渠净化稻田排水动力学分析和生物相特征

本研究以太湖流域常见的菱角、水葫芦、梭鱼草、圆币草等水生植物和人工水草、塑料立体弹性填料为生态强化载体,构建"水生植物-载体生物膜-菌藻"复合型生态系统,研究了稻田排水中的氮、磷等营养元素的去除特性,构建氮、磷污染物的降解动力学模型,并调查了沟渠内"微生物-藻类"生物相特征.结果表明,生态沟渠运行期间,随着水稻进入不同...

Dynamics analysis and biofacies characteristics of drainage from paddy fields purified by ecological ditches

In this study,artificial aquatic weeds,plastic stereoelastic fillers and aquatic plants native to Taihu Lake,such as water hyacinth,water chestnut,pickerelweed,and pennisetum,were used as ecological reinforcement carriers to construct an aquatic plant-carrier biofilm-bacteria and algae complex ecosystem.Ecological ditches were utilized as research environments to reveal the removal characteristics of nitrogen(N),phosphorus(P)and other nutrients in paddy field drainage,to construct the degradation kinetic models of nitrogen(N)and phosphorus(P)pollutants,to clarify the biofacies characteristics of"microorganism-algae"interactions in ditches.The results showed that during the operation of ecological ditches,the removal rates of nitrogen(N),phosphorus(P)and other nutrients decreased as the rice enters different growth stages.The mean concentration removal efficiencies in the ecological ditches for total phosphorus(TP),ammonia nitrogen(NH3-N),total nitrogen(TN)and nitrate nitrogen(NO3-N)were 87.1%,92.3%,77.5%and 88.6%,respectively.Among them,the ammonia nitrogen(NH3-N)removal rate was the highest,while the chemical oxygen demand(CODMn)removal efficiency was not significant.The degradation trends of the pollutants in each experimental period conform to first-order kinetic degradation models.Biofacies analysis revealed that the species of microorganisms and algae,the Shannon-Weiner index and other diversity indices increased with the continuous operation of the complex ecosystem.This showed that the improved water quality of the complex ecosystem was more suitable for the survival and reproduction of many kinds of bacteria and algae.Additionally,bacteria,algae,aquatic plants and biofilms attached on the surfaces of the complex ecosystem had synergistic effects on pollutant removal,and strengthen the self purification capacity of the ecological ditch.