【作者】 陈翠雪；

【导师】 卢英华；

【作者基本信息】 厦门大学 ， 生物化工， 2009， 硕士

【摘要】 随着城市化进程的加快和工业化程度的提高,城市湖泊受到的污染越来越严重,水域呈富营养状态。水环境的恶化,严重制约城市的经济可持续发展,并影响到市民的生存质量。生物修复是近年来兴起的一项低投资、见效快、无二次污染的技术,目前已成功应用到废水处理、农业、畜牧业、水产养殖业和环境保护等领域。本文针对筼筜湖尽管经过十几年的综合整治,目前仍存在部分污染的状况,对其污染水平进行了比较全面的调查研究,并选用不同的复合微生物菌剂进行微生物修复试验研究,主要研究工作及结果如下:（1）利用等离子电感耦合质谱仪、气相色谱、元素分析仪等现代分析仪器对沉积物中的重金属、氮、硫、有机物等进行测试,采用聚合酶链反应—变性梯度凝胶电泳技术（PCR-DGGE）检测方法对沉积物样品的微生物多样性进行初步的分析。结果表明,筼筜湖沉积物中重金属的污染程度目前属于中度污染,沉积物中重金属元素的污染程度顺序是:As>Ni>Pb>Cu>Cr>Zn;筼筜湖表层沉积物中总氮、总碳、总有机碳和总硫含量最高,各站位分布规律如下:内湖>干渠>外湖>松柏,污染主要来源为陆源物质;筼筜湖各站位沉积物中16种多环芳烃的总含量顺序为:内湖>干渠>外湖>松柏,PAHs主要来自汽油、柴油及煤等燃料不完全燃烧的污染;正构烷烃主要分布于nC₂₂-nC₃₀,来源主要以水生植物和陆源高等植物为主;四个站位中均含有如下饱和脂肪酸:C10:0、C12:0、C14:0、C15:0、C16:0和C18:0,指示了筼筜湖沉积物中微藻对沉积物的贡献;使用酚氯仿抽提沉积物中菌体总DNA,以341F和517R为引物,对16SrDNA基因片段进行PCR扩增,可得到长度为200 bp的DNA片段,通过DGGE进行生物多样性分析,基本把握筼筜湖各站位的微生物群落多样性。（2）选择合适的复合菌剂,在实验室进行生物修复筼筜湖污染水体的初步探索,以期有效的改变水质状况,为实现对筼筜湖的治理提供基础数据。试验结果表明,复合菌剂修复筼筜湖污染水体的试验中保持微量曝气,维持水体中的溶解氧在5⁶ mg/L,有利于生物修复过程;在相同的试验条件下,对比投加CB菌剂和EM菌剂对筼筜湖污染水体的修复效果,发现EM菌剂有较大降解有机物的潜力,修复污染水体的综合效果较佳;采用特定的培养基复壮EM原液,得到富集光合菌、酵母菌、乳酸菌和放线菌四种有益微生物菌的最佳培养条件;对EM富集菌剂不同投加量的效果进行试验,结果发现,投加0.8 mL富集菌液（四种优势菌群按1:1:1:1的比例混合）的试验组修复污染水体具有显著效果,试验期间水体中化学需氧量、总氮和总磷分别降低了39.56%、66.98%和68.42%;水体的污染情况对生物修复的效果有影响:EM菌剂对高污染水体的化学需氧量降解效果优于低浓度污染水体,且对高污染水体化学需氧量的去除周期较短。更多还原

【Abstract】 With the acceleration of urbanization and the improvement of industrialization process,the level of pollution in urban lakes is more and more serious and the waters are in eutrophic state.The eutrophication of water environment seriously restricts the city’s economic sustainable development and has effect on the resident life quality. Bioremediation is a new technology which has many advantages such as low investment,high efficiency and no secondary pollution.Now the technology has been successfully applied to the fields of wastewater treatment,agriculture,animal husbandry,aquaculture and environmental protection.This study is focused on the pollutant level of sediments after 20 years continuous rehabilitation in Yundang Lagoon and bioremediation of the polluted water by direct adding different kind of mixed microorganisms.Main work and results are as follows:（1） Different techniques such as Inductively Coupled Plasma Mass Spectrometry, Gas Chromatography and elemental analysis were employed to characterize the heavy metals,nitrogen,sulfur and organic matter in the sediment of Yundang Lagoon. Polymerase Chain Reaction--Denaturing Gradient Gel Electrophoresis（PCR- DGGE） analysis of 16S rDNA genes was carried out in order to determine the microbial diversity of Yundang Lagoon.The results show that the pollution in Yundang Lagoon was moderate and the ranking of heavy metals followed the order:As＞Ni＞Pb＞Cu＞Cr＞Zn.The contents of TN,TC,TOC and TS from surface sediments of Yundang Lagoon were the highest and the distribution of the stations were as follows:S2＞S3＞S1＞S4.The total content of sixteen PAHs from four stations of Yundang Lagoon followed the order:S2＞S3＞SI＞S4,and mainly came from incomplete combustion of fuels such as gasoline,diesel and coal.n-Alkanes were mainly distributed in the nC₂₂-nC₃₀ and mainly from aquatic plants and land-based plants.Fatty acid from four stations contained the following:C10:0,C12:0,C14:0,C15:0,C16:0 and C18:0, indicating the contribution of microalgae to the sediments.Total DNA was extracted from sediments with the Phenol-Chloroform Extraction method,and the V3 variable region of 16S rDNA gene was PCR-amplified.DNA fragments of 200 bp were obtained as PCR products.DGGE analysis of 16S rDNA genes showed that the community diversity was abundant in different stations of Yundang Lagoon.（2） Bioremediation of real wastewater from Yundang Lagoon was carried out by direct adding different kind of effective microorganisms（EM） in order to change water quality effectively and provide the basic data for rehabilitation.The results show that maintaining dissolved oxgen at 5-6 mg/L by gentle aeration was effective to bioremediation process.EM were more capable of degrading organic matter than CB and had combined effect on bioremediation of polluted water.The enrichment of EM showed that four predominant microorganisms（photosynthetic bacteria,yeast, lactobacillus and actinomycete） could be cultivated by different methods.Change of the dosage of microorganisms in EM would influence the effect of bioremediation. The optimal adding dosage was 0.8 mL enriched bacteria（four predominant microorganisms in accordance with the proportion of 1:1:1:1）.The removal rates of COD_Mn,TN and TP were 39.56%,66.98%and 68.42%during the experiment, respectively.The concentration of pollutants in water also influenced the effect of bioremediation.COD degradation rate was increased and the removal time of COD was shorter during the treatment of higher polluted water bodies by EM.更多还原