【作者】 焦燕；

【导师】 赵庆良； 金文标；

【作者基本信息】 哈尔滨工业大学 ， 环境科学与工程， 2010， 博士

【摘要】 随着城市发展和人口增加,城市内河污染日趋严重。研发适宜的水体净化技术是恢复河流生态系统健康并实现可持续发展的重要途径之一。本文以我国南方典型的重污染城市内河——深圳布吉河河水为研究对象,贯彻以河流为主体的流域治理理念,以研发高效、经济、可持续、占地面积小的水质净化技术为目的,运用原位-异位联合生物处理技术,结合微生物和水生植物的各自优势处理重污染河水,以期为我国污染水体的生物修复计划提供借鉴。布吉河水质污染状况及微生物群落结构分析表明,布吉河属于典型的耗氧性有机污染,氮素污染是布吉河水质最突出的问题。水体中平均COD和BOD浓度分别为211±50.2 mg/L和117±21.3 mg/L,总氮和氨氮浓度分别为29.8±8.86 mg/L和24.4±8.3 mg/L。氮循环菌群落分布及其功能研究表明,快速的生长能力和较强的活性,使氨化菌和反硝化菌在河流中广泛分布,分别为1012 MPN/ml和106MPN/ml。硝化细菌在水体和底泥中分别仅约102 MPN/ml和104 MPN/g。相关性分析表明,非点源污染的存在,是河流污染严重的原因之一。此外,河流生态系统中氮素循环相关菌群的数量分布严重失衡,使氮素的转化和去除途径受阻,导致大量的氮素以氨氮的形式滞留于水体,加重了河流的氮素污染。因此,采取一些行之有效的生物治理措施迫在眉睫。采用新型的强化生物膜-活性污泥复合工艺(EHYBFAS)对上游高污染河水进行异位处理。复合工艺能够在短停留时间(HRT=3.5h)内有效去除有机污染物,当进水负荷为0.33~0.93 kg BOD/(m3·d)和0.93~2.53 kg COD/(m3·d)时,BOD和COD的平均去除率分别为86.0±3.6%和83.7±4.6%。当进水负荷为0.15~0.32 kg TN/(m3·d)和0.11~0.22 kg NH4+-N/(m3·d)时,总氮和氨氮的去除率分别为25.7±7.2%和22.2±12.7%。MPN-Griess检测结果表明,硝化菌占总菌量的比例在混合液中为0.21%~0.3%之间,在生物膜载体上为0.12%~0.6%之间。自养菌比例过低,削弱了硝化反应,是导致氮素去除率低的主要原因。采用PCR-DGGE对不同生物反应池中的氨氧化细菌(AOB)进行检测,结果显示EHYBFAS工艺完成了AOB的自然选择,与缺氧池相比,好氧池内的AOB菌数量差异不显著,表明好氧池内亚硝化速率较慢。对主要条带进行克隆测序共获得9种不同的16s rDNA序列,其GenBank登陆号为GU073369-GU073378,BLAST结果表明,其中5个序列与已知的Nitrosomonas sp.属细菌均有大于98%的相似性。此外,在活性污泥1号数学模型与生物膜上碳氧化和硝化的经验公式相结合的基础上,建立了生物膜-活性污泥全耦合数学模型,且能够较好的反映出水水质的变化。为配合EHYBFAS工艺对污染河水的异位处理,尝试以河道空间作为处理场所,采用生物接触氧化工艺进一步净化河流水质。以布吉河水质净化厂出水口下游600 m处河水作为试验进水,模拟河道状况设计动态小试试验装置,通过添加微生物功能菌剂构建生物强化系统。生物接触氧化技术能有效去除氮素。平均出水总氮和氨氮浓度分别为13.37±3.52 mg/L和7.28±2.61 mg/L。投加高效菌剂后,TN去除率为50.32%,比投菌前高24.42%,氨氮去除率为60.1%,比投菌前高25.6%。此外,生物膜载体有效增加了微生物生物量,特别是投加高效菌剂后,硝化细菌数量明显增加,占细菌总数的1.31%。微生物群落的DGGE图谱和数量分析也表明,投加的高效菌剂,增加了微生物的群落多样性和种群数量,特别是硝化细菌的数量,优化了氮素循环相关菌群的结构分布。为了再现城市内河的生态景观功能,在生物接触氧化技术处理污染河水的基础上,探讨生物接触氧化工艺结合水生植物处理河水的效果,研究适合河流生态系统恢复的原位生物处理技术。结果表明,水生植物-生物接触氧化工艺能够有效去除氮素,平均出水总氮和氨氮浓度分别为15.5±1.84 mg/L和6.6±0.56 mg/L。种植植物后, TN去除率为56.9%,比种植植物前提高21.0%,氨氮去除率为72.5%,比种植植物前提高28.9%。水生植物增加了水体中微生物的生物量,特别是硝化细菌,其占总菌量的比例从种植植物前的0.12%增长到种植植物后的0.39%,优化了氮循环相关菌群的结构分布。更多还原

【Abstract】 Urban river are often heavily polluted, a situation that is not confined to a particular geographic region of the world, but common to all areas subject to urbanization. It is the potentially cost-effective and environmentally acceptable remediation technology that has been particularly emphasized as a significant approach so as to realize healthy and sustainable river ecosystem. Taking a typical polluted urban stream in Shenzhen (China) as the target stream, the aim of this study is to discuss the pollutants removal by combined bio-trentment technology.The results would provide a basis for reasonable, highly effective, economical remediation technology for the bioremediation scheme of the polluted urban stream. Results of pollution survey indicated that Buji stream suffered from serious organic and nitrogen pollution. The mean value of COD, BOD, TN and NH4+-N were 211±50.2 mg/L, 117±21.3 mg/L, 29.8±8.86 mg/L and 24.4±8.3 mg/L respectively. The investigation of ecological structure and functions of nitrogen-related bacteria showed that fast growth rate and high activity of ammonifying bacteria and denitrifying bacteria made them predominant in Buji stream. The MPN of ammonifying bacteria and denitrifying bacteria reached about 1012 MPN/ml and 106 MPN/ml respectively in Buji stream. In contrast, the MPN of nitrifying bacteria in water and sediment were about 102 MPN/ml and 104 MPN/g respectively. The imbalance distribution of various nitrogen-related bacteria resulted in ammonia nitrogen accumulation and serious nitrogen pollution in Buji stream.Full-scale enhanced hybrid biofilm-activated sludge process (EHYBFAS) with short hydraulic retention time (HRT=3.5h) was a novel and promising for wastewater treatment. Results indicated that EHYBFAS were capable of achieving efficient organic removals. The average removals of BOD and COD achieved 86.0±3.6% and 83.7±4.6% at organic loading rates of 0.33~0.93 kg BOD/(m3·d) and 0.93~2.53 kg COD/(m3·d), respectively.The removal of TN and NH4+-N were 25.7±7.2% and 22.2±12.7% when the influent volume loading was 0.15~0.32 kg TN/(m3·d) and 0.11-0.22 kg NH4+-N/(m3·d), respectively. In EHYBFAS system, nitrogen-related bacteria were rich but the proportion of nitrifying bacteria was very low (0.21~0.3% in mixed liquor, 0.12~0.6% in fibrous carriers), which could weaken nitration and finally resulted in low removal rate of TN and NH4+-N. AOB community was investigated by PCR-DGGE. Results demonstrated the natural successions of AOB were completed successfully. The prominent bands were excised from DGGE gels and sequenced. Nine 16s rDNA sequences were obtained and the Genbank accession no. was from GU073369 to GU073378. Sequence analyses revealed five 16s rDNA sequences belonged to Nitrosomonas lineage and the similarity ranged from 98 to 99%. A fully coupled biofilm-activated sludge model is proposed and the simulation results indicate that the numerical simulation values of the coupled model were more consistent with real values.The combined bio-treatment technology of in-situ and en-situ was a practical and feasible method for stream regulation. In this study, a pilot-scale biological contact oxidation ditch (BCOD) was bioaugmented by inoculating enriched nitrifying bacteria for treatment of nitrogen-rich stream water. Results showed that the augmented BCOD obtained the effluent concentration of 13.4±3.5 mg/L of TN and 7.3±2.6 mg/L of NH4+-N, respectively. The removals of TN and NH4+-N reached 50.3% and 60.1%. The microbial biomass increased greatly in biofilm carriers especially after bioaugmentation and nitrifying bacteria accounted for about 1.31% of the nitrogen-related bacteria. Concomitant increases in the diversity of the bacterial community were also observed which had optimized the community structure of nitrogen-related bacteria and enhanced denitrification capacity.The introduction of aquatic plants into BCOD for treatment of polluted stream water not only improved treatment effect but also could overcome the defects of phytoremediation measures such as high operating conditions, long processing time and large occupation area. Results showed that the effluent TN and NH4+-N concentration were 15.5±1.84 mg/L and 6.6±0.56 mg/L and the removals of TN and NH4+-N reached 56.9% and 72.5% respectively. In addition, microbial biomass increased greatly due to aquatic plant especially the nitrifying bacteria which accounted for about 0.39% of the nitrogen-related bacteria from the initial 0.12%. The results had optimized the community structure of nitrogen-related bacteria and enhanced denitrification capacity.更多还原