不同流速下沉水植物对于底泥再悬浮的影响研究

发布时间：2018-08-04 22:09

【摘要】：底泥再悬浮影响着水生态系统的稳定,而水体流速影响着底泥再悬浮的程度。沉水植物对底泥具有固着作用,对底泥的再悬浮具有再沉降的作用。一方面沉水植物的根对底泥具有固定作用,另一方面沉水植物的茎叶可以降低水体的流速,使得水体的悬浮颗粒物可以再次沉降到底泥中或者附着在沉水植物茎叶的表面。为明确不同流速下沉水植物对底泥再悬浮的抑制效果,以黑藻(Hydrilla verticillata(Linn.f.)Royle)和狐尾藻(Myriophyllum spicatum L.)、苦草(Vallisneria natans(Lour.)Hara)和菹草(Potamogeton crispus L.)两组受试植物,分别于夏季和冬季,在室内水槽中进行模拟试验。结果表明:(1)在水体流速分别为0,10,20,40,60,80 cm/s,沉水植物生物量为1 kg/m2时,菹草组和苦草组对底泥再悬浮都具有抑制效果,对浊度的抑制率分别为47%~60%,57%~93%;对总氮的抑制率分别为23%~35.8%,31%~47.1%;对总磷的抑制率分别为19.3%~30.6%,19.8%~43%。菹草的抑制效果优于苦草。对照组、菹草组以及苦草组对应的将动未动状态的流速为:20 cm/s、20 cm/s、10 cm/s;对应的少量动状态的流速为:40 cm/s、40 cm/s、20 cm/s;对应的普遍动状态的流速为:60 cm/s、60 cm/s、40 cm/s,菹草和苦草的种植虽然改变了底泥起动状态的流速,但对每种起动状态下水体浊度影响不大。因此,菹草与苦草的种植可以有效的降低底泥再悬浮对水体影响,能有效的固着底泥,对于维持湖泊生态环境的稳定具有良好的效果。(2)在水体的流速分别为0,10,20,40,60,80 cm/s,沉水植物生物量为2 kg/m2时,黑藻组和狐尾藻组对底泥再悬浮都具有抑制效果,对总悬浮固体含量的抑制率分别为68%~85%,33%~50%;对浊度的抑制率分别为71%~83%,30%~52%;对总氮的抑制率分别为53%~57%,26%~31%;对总磷的抑制率分别为39%~51%,16%~36%。黑藻的抑制效果优于狐尾藻。对照组、黑藻组以及狐尾藻组对应的将动未动状态的流速为:40 cm/s、40 cm/s、20 cm/s;对应的少量动状态的流速为:60 cm/s、60 cm/s、20 cm/s;对应的普遍动状态的流速为:80 cm/s、80 cm/s、40 cm/s,黑藻和狐尾藻的种植虽然改变了底泥起动状态的流速,但对每种起动状态下总悬浮固体含量以及水体浊度影响不大。因此,黑藻与狐尾藻的种植可以有效的降低底泥再悬浮对水体影响,能有效的固着底泥,对于维持湖泊生态环境的稳定具有良好的效果。
[Abstract]:Sediment resuspension affects the stability of water ecosystem, and the velocity of water affects the degree of sediment resuspension. Submerged plants have the function of fixation on sediment and resettling on resuspension of sediment. On the one hand, the roots of submerged plants have fixed effect on the sediment, on the other hand, the stems and leaves of submerged plants can reduce the velocity of water body, so that the suspended particles of the water body can be settled to the end of the mud or attached to the surface of the stems and leaves of submerged plants. In order to determine the inhibitory effect of submerged plants on sediment resuspension at different velocities, (Hydrilla verticillata (Linn.) Royle) and (Myriophyllum spicatum L.), (Vallisneria natans (Lour.) Hara) and (Potamogeton crispus L.) were used in this paper. Two groups of plants were simulated in indoor flume in summer and winter. The results showed that: (1) when the water flow velocity was 0 ~ 10 ~ 20 ~ (20) ~ (40) C ~ (60) cm / s and the submerged plant biomass was 1 kg/m2, both Potamogrium crispus and Prunus crispus had an inhibitory effect on sediment resuspension. The inhibition rates on turbidity were 470.60 and 57.933, respectively; the inhibition rates on total nitrogen were 230.35. 835. 835. 835. 831 and 47.1, respectively; and on total phosphorus were 19. 3 and 30. 6 and 19.843, respectively. The inhibitory effect of P. crispus was better than that of A. crispus. Control group, The velocity of flow in the unmoved state of Potamogriogrium crispus and Prunus crispus is: 20 cm / s / s 10 cm / s; the flow rate of a small amount of moving state is 40 cm / s / s; the velocity of general dynamic state is 60: cm / s 60 cm / s 40 cm / s; the planting of crispus and Prunus crispus has changed although the planting of P. crispus has changed the velocity of 40 cm / s; the velocity of general movement is 60: cm / s 60 cm / s 40 cm / s. The velocity of flow in the starting state of the sediment, But it has little effect on turbidity of water under each starting state. Therefore, the planting of Potamogrium crispus and Prunus crispus can effectively reduce the effect of sediment resuspension on the water body, and can effectively fix the sediment. It has a good effect on maintaining the stability of the ecological environment of the lake. (2) when the flow velocity of water is 0 ~ 10 ~ (20) ~ (40) ~ (60) cm / s, and the biomass of submerged plant is 2 kg/m2, both the black algae group and the foxtail algal group can inhibit the resuspension of the sediment. The inhibition rates of total suspended solids content were 680.The inhibition rates of turbidity were 71and 83300.The inhibition rates of total nitrogen were 5355726262.The inhibition rates of total phosphorus were 3951C 16361g and 3951g / kg, respectively.The inhibition rates of total suspended solids were 3951C and 36361.The inhibition rates of total nitrogen and total nitrogen were respectively 3951and 36361.The inhibition rates of total suspended solids were as follows: (1) the inhibition rate of total suspended solids content was 885%. The inhibition rate of total phosphorus was 3 951%. The inhibitory effect of black algae is better than that of foxtail algae. Control group, The flow rate of the black algae group and the foxtail algae group is: 40 cm / s / s, 20 cm / s respectively, respectively; the current velocity of the normal dynamic state is 20 cm / s / s respectively; the current velocity of the normal dynamic state is: 80 cm / s 80 cm / s 40 cm / s / s; the growth of black algae and foxtail algae is changed though Changing the velocity of flow in the starting state of the sediment, But it has little effect on the total suspended solid content and turbidity in each starting state. Therefore, the cultivation of black algae and foxtail algae can effectively reduce the impact of sediment resuspension on the water, can effectively fix the sediment, to maintain the stability of the lake ecological environment has a good effect.
【学位授予单位】：武汉理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X173;X52

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