【作者】 赵淼；

【导师】 闫永胜；

【作者基本信息】 江苏大学 ， 环境工程， 2010， 硕士

【摘要】 水体富营养化是困扰着世界各国的水污染问题之一。我国湖泊河流众多,也受到不同程度的污染。太湖作为重点治理的富营养化浅水湖泊之一,外污染源目前得到了一定程度的控制,但其内源污染仍在持续。影响湖泊沉积物营养盐内源释放的因素有很多,其中富营养化的产物藻体将与其它环境因素共同作用影响沉积物营养盐释放。本文以太湖梅梁湾为研究原型区域,采集水样和泥样,通过室内模拟实验,研究莱茵衣藻(Chlamydomonas Reinhardtii)增殖、沉降与死亡过程对底泥氮素动态的影响。通过添加莱茵衣藻藻液于含有不同浓度的NO3--N和NH4+-N水-泥体系中,在实验室培养条件下研究莱茵衣藻对无机氮利用偏好,结果表明：莱茵衣藻在增殖过程中同时消耗NO3--N、NH4+-N,但较NH4+-N而言,莱茵衣藻更倾向于利用NO3--N；而且,以NO3--N含量为主导的培养体系更有利于藻体增殖。添加莱茵衣藻藻液于水-泥体系中,在实验室不同温度培养条件下研究莱茵衣藻增殖与沉降过程对底泥氮素动态的影响,结果表明：①莱茵衣藻在大量增殖过程中伴随着藻体沉降,藻体沉降过程部分藻体死亡分解(高温条件比较明显)。高温条件虽然有利于藻体大量增殖,但是也加速了藻体个体的死亡分解,低温条件下藻体具有较低的增殖速率和分解速率,存活时间较长。②莱茵衣藻在大量增殖过程中促进了底泥中NH4+-N的释放,死亡过程加速了上覆水中NH4+-N的增加。③莱茵衣藻在大量增殖过程中Nar、Nir和Urease活性明显增强,氮素转化的结果是加速硝态氮反硝化逸失,而不是导致异化成氨过程(铵态氮含量增加)。添加不同浓度的莱茵衣藻藻液于太湖水样中,在实验室培养条件下研究无底泥条件莱茵衣藻增殖、沉降与死亡过程对水体氮素动态变化影响,结果表明：莱茵衣藻增殖、沉降过程消耗体系中NO3--N、NO2--、NH4+-N,死亡过程中释放数量可观的NH4+-N。更多还原

【Abstract】 Water eutrophication is a serious environmental problem in the world. There are numerous lakes and rivers that have been polluted in different levels in China. Taihu lake in China is one of the key administration eutrophication Shallow lakes. Currently, external pollutant sources got certain degree of control but releases of nutritive salt from sediment have always stimulated entrophication in Lake Taihu. As an important parameter that affects the release processes of nutrition salt from sediment, algae itself and various environmental parameters take actions together. Water and sediment samples from Meiliang Bay in Lake Taihu, Eastern China, were employed to investigate the effects of Chlamydomonas Reinhardtii proliferation, sedimentation and decay on nitrogen release processes from sediment under incubation conditions.Through studying utilization preference of Chlamydomonas Reinhardtii on inorganic nitrogen, the results showed that algae proliferation consumed NO3--N, NH4+-N. But NO3--N in the system more tended to been utilized by algae than NH4+-N. Moreover, the culture system with the dominant NO3--N was beneficial to enhance algae proliferation. This would be significant to further study effects of Chlamydomonas Reinhardtii proliferation and sedimentation on changes of nitrogen from water and sediment.Through studying effects of Chlamydomonas Reinhardtii proliferation and sedimentation on nitrogen concentrations in water and sediment, the results showed high temperature (35℃) was not only beneficial for algae proliferation and sedimentation but also accelerating algae decay. In contrast, there were only low proliferation and decay rates of algae under the low temperature condition (15℃) Algae sedimentation was found to be simultaneous with their proliferation and suspending. Most of algae died and decayed during the sedimentation, and minority of them survived on the surface of sediment. In addition,the mount of NH4+-N released from sediment got rise with algae proliferation, and the NH4+-N concentrations in water increased with algae decay. The algae proliferation obviously enhanced the activities of nitrate reductase, nitrite reductase and urease in sediment, which maybe accelerate NO3--N being transformed into the gaseous N rather than NH4+-N.Effects of Chlamydomonas Reinhardtii proliferation, sedimentation and decay on dynamic processes of nitrogen in water were studied under exclusive sediment condition. The results showed that NO3--N, NO2--N and NH4+-N in the system were all consumed by algae. And the release of NH4+-N from water was enhanced in the process of algae decay.更多还原