• 关键词：颤蚓  迁移  分布密度  底泥性质

• 基金项目：国家重大科技专项课题(No.2009ZX07423-003);国家科技支撑计划项目(No.2006BAJ08B08)

• 聂小保
• 1. 西安建筑科技大学环境与市政工程学院, 西安 710055; 2. 长沙理工大学水利学院, 长沙 410076

• 黄廷林
• 西安建筑科技大学环境与市政工程学院, 西安 710055

• 张金松
• 深圳水务集团, 深圳 518031

• 李伟
• 西安建筑科技大学环境与市政工程学院, 西安 710055

• 李晓钰
• 西安建筑科技大学环境与市政工程学院, 西安 710055

• 王宝山
• 西安建筑科技大学环境与市政工程学院, 西安 710055

• 摘要：通过实验室模拟颤蚓的迁移,研究了颤蚓分布密度、底泥性质对颤蚓迁移运动的影响.结果表明,分布密度增大引起食物短缺,颤蚓迁移率首先增大,之后由于迁移运动的能量消耗导致迁移率减小,当分布密度大于8×10⁴条·m^-2后,颤蚓对食物极度竞争使其开始大规模迁移,最大迁移率为36.75%.底泥有机质在丰富颤蚓食物源,增大其迁移率的同时,也降低了溶解氧浓度,导致迁移率减小,有机质含量由3.93%增加至5.90%时以迁移率增大为主,大于5.90%时则以迁移率减小为主.TN、TP可改变底泥中微生物群落结构,引起颤蚓食物组分变化,从而影响颤蚓迁移,TN和TP含量分别在3.36～5.65mg·g^-1和0.95～1.87mg·g^-1范围时,TN含量的增加减小了颤蚓迁移率,TP含量的增加则增大颤蚓迁移率;继续增大含量,颤蚓对TN具有一定耐受性,迁移率稳定在20%左右,对TP则表现出排斥性,含量超过1.87mg·g^-1后,迁移率从42%降为0.5%.颗粒粒径对颤蚓迁移的影响主要是由颗粒中有机质含量而非粒径本身决定,粒径小于0.15mm和大于0.55mm的颗粒适宜颤蚓生存,前者有机质含量高,后者则颗粒间空隙大,颤蚓可快速通过并获取更多的食物.

• Abstract：In this study,the effects of population density and sediment properties on the migration of Tubifex tubifex were investigated using a lab-scale simulation system. The results indicated that both the population density and the sediment properties had significant effects on the migration behavior of T. tubifex. The migration rate increased when population density increased since the increased population density resulted in a shortage of food. Thereafter,the migration rate decreased because the energy for migration was consumed in the migration process. The maximum migration rate was observed when the population density was 8×10⁴ in d·m^-2. This may be due to the extreme competition for food at that specific population density. The results show that the food source increased when organic matter content increased from 3.93% to 5.90%. This results in the increase of migration rate of T. tubifex and acts as the dominant factor affecting the migration rate. The dissolved oxygen (DO) decreased when organic matter content was higher than 5.90%. This,however,results in a decrease of migration rate. Total nitrogen (TN) and total phosphorus (TP) could change the structure of the microbial community in the sediment. This subsequently leads to a change of food source and migration behavior of T. tubifex. The results show that the migration rate decreased when TN concentration increased from 3.36 mg·g^-1 to 5.65 mg·g^-1. It is more important however to note that the increasing TN concentration did not affect the migration rate at TN concentrations higher than 5.65 mg·g^-1. The migration rate increased when TP concentration increased from 0.95 mg·g^-1 to 1.87 mg·g^-1. However,the migration rate significantly decreased from 42% to 0.5% at TP concentrations higher than 1.87 mg·g^-1. The results show that the migration rate was significantly affected by particulate matter more due to the organic matter content in the particles rather than the particle size. Sediments with particle size less than 0.15 mm and larger than 0.55 mm are more suitable for the survival of T. tubifex. The former had higher organic matter content,while the latter had larger pore size in the particles,which allows the T. tubifex to move and obtain more food from the particles.

• Key words：Tubifex tubifex  migration  population density  sediment properties

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