【作者】 苏彩丽；

【导师】 余泳昌；

【作者基本信息】 河南农业大学 ， 农业生物环境与能源工程， 2010， 博士

【摘要】 玉米、大豆、小麦、薯类等农产品加工利用过程中,会产生大量废水,这类废水不仅有机物浓度高,而且还含有高浓度硫酸盐和氨氮。研究人员对高硫酸盐废水的厌氧处理工艺和设备进行了广泛研究,但在厌氧处理过程中,硫酸盐会转化成有毒且对设备腐蚀性强的硫化物,氨氮也不能有效去除,需经过进一步处理才能有效解决农产品加工废水污染问题。目前采用的传统好氧生物脱氮除硫工艺,存在着工艺复杂、投资和运行费用高等缺点。寻求低成本、高效率的先进废水处理工艺,对农产品加工企业的发展具有重要意义。好氧颗粒污泥工艺是近年来发展起来的污水处理新工艺,与传统的絮状活性污泥相比,具有容积负荷高、沉降性能好、占地小、投资低等优点。由于颗粒污泥对溶解氧传质的限制,使好氧颗粒污泥内部形成好氧区、缺氧区和厌氧区,可使好氧和厌氧微生物在颗粒内部共存,实现多种污染物的同步去除,具有良好的发展前景。本研究利用好氧颗粒污泥的特点,进行了脱氮除硫好氧颗粒污泥的培养及特性研究,并重点对其脱氮除硫的过程及影响因素进行了研究,为好氧颗粒污泥在农产品加工废水处理中的应用提供理论依据。主要研究结果如下:（1）在SBR反应器中对脱氮除硫好氧颗粒污泥的培养和污泥特性进行了研究。以厌氧颗粒污泥为接种污泥,采用人工配制的含硫化物和氨氮的有机废水,通过控制运行条件,在21d内可培养出脱氮除硫好氧颗粒污泥。好氧颗粒污泥粒径以1～1.5mm为主,SVI为30～40mL/g,微生物组成以短杆菌为主,外部包裹大量丝状菌。进水硫化物、COD和NH₄⁺-N浓度分别保持在50mg/L、550mg/L和55mg/L时,好氧颗粒污泥对硫化物、COD和NH₄⁺-N的去除率分别达到99%、80%和99%以上。（2）研究了硫化物对好氧颗粒污泥脱氮除硫效果和污泥稳定性的影响。当进水COD和NH₄⁺-N浓度分别保持在550mg/L和55mg/L时,硫化物浓度从50mg/L逐步提高到300mg/L时,硫化物去除率一直保持在99%以上,COD和NH₄⁺-N的去除率在提高浓度初期略有下降,但下降幅度不大,经过一周左右的恢复,COD和NH₄⁺-N去除率又可分别达到80%和99%以上。但硫化物浓度超过100mg/L时,引起丝状菌过度繁殖,SVI大于100mL/g,系统变得不稳定。（3）对脱氮除硫好氧颗粒污泥的微生物种群进行了研究。PCR-DGGE分析结果表明,稳定运行期,脱氮除硫好氧颗粒污泥中微生物种群比较丰富,其结构也比较稳定。微生物群落以β-变形菌（β-proteobacterium）和拟杆菌（Uncultured Bacteroidetes bacterium）为主,分别占总数的27.27%和18.18%。优势菌群有反硝化细菌（Thauera sp.）、异氧硝化反硝化细菌（pseudomonas alcaligenes）及发硫菌属（Uncultured Thiothrix sp.）等。（4）对好氧颗粒污泥的脱氮除硫过程及影响因素进行了研究。SBR反应系统中的脱氮途径包括硝化反硝化、同步硝化反硝化和异养硝化反硝化;硫化物主要是通过发硫菌属（UnculturedThiothrix sp.）的生物氧化作用去除的。DO对好氧颗粒污泥脱氮除硫的效果有显著影响。（5）对高硫化物浓度下,好氧颗粒污泥仍能高效脱氮的原因进行了分析。硫化物的氧化去除主要发生在反应开始前30min,而氨氮的去除主要发生在30～120min。在高进水硫化物浓度下,SBR系统仍表现出良好的脱氮效果,是由硫化物比氨氮快速氧化的特点及好氧颗粒污泥的层状结构决定的。（6）对好氧颗粒污泥的传质及动力学进行了研究。DO和硫化物的传质对硝化反硝化脱氮影响较大,而氨氮的传质对其去除速率影响较小。好氧颗粒污泥对COD和NH₄⁺-N去除的动力学模型分别为:更多还原

【Abstract】 The processing and utilization of agricultural products such as maize, soybean, wheat and potato can generate a large amount of organic wastewater which contains high concentrations of sulfate and ammonia. Researchers conducted an extensive investigation of the technologies and equipments of anaerobic biological treatment of sulfate-rich wastewater, However, in the process of anaerobic treatment, sulfate changed into a kind of toxic sulfide that was highly corrosive to the equipments, besides, the ammonia could not remove effectively,it required a further treatment to resolve the problem of wastewater pollution from agricultural products processing. There are several defects in the currently-adopted aerobic sulfide and ammonium removal technology, namely, complex processing, big investment and high operating cost. Therefore, to seek an advanced, low-cost and highly-efficient wastewater treatment is of great significance to the development of agricultural products processing business.Compared to the conventional activated sludge flocs, the newly-developed aerobic granular sludge technology have Several advantages,such as high volumetric loading, good settling ability, small occupying space, low investment and so on. Owing to the restrict mass transfer of the dissolved oxygen in granules, so inside the aerobic granules it form Aerobic zone, Anoxic zone and anaerobic zone, which enables the co-existence of aerobic and anaerobic microorganism and realizes simultaneous removal of many kinds of pollutant. The aerobic granular sludge technology has a good prospect.Drawing on the properties of aerobic granular sludge, this research investigated the cultivation and characters of the aerobic granules for ammonium and sulfide removal, especially the removal process and influencing factors, which will provide theoretical basis for the application of aerobic granules in agricultural products processing wastewater treatment.The main results are as follows:（1） Cultivation and characters of the aerobic granules for ammonium and sulfide removal in a sequencing batch reactor were studied. Using anaerobic granular sludge as seed sludge, the aerobic granules for ammonium and sulfide removal were cultivated fed with synthetic ammonia and sulfide-rich wastewater under controlled operational conditions in 21 days. The diameter of most of the aerobic granules was about 1-1.5 mm and the SVI was 30-40 mL/g. The granule was dominated by Brevibacterium, and wrapped by a large number of filamentous bacteria. When the sulfide influent, COD and NH₄⁺-N concentration were 50mg/L,550mg/L and 55mg/L, the removal efficiencies of S^2-, COD and NH₄⁺-N were >99%, >80% and >99%, respectively.（2） The influence of sulfide on removal effect and sludge stability was investigated. When the COD and NH₄⁺-N concentration were 550mg/L and 55mg/L and the S^2- concentration increased from 50mg/L to 300mg/L, the removal efficiency of S^2- maintained above 99%, and the removal efficiencies of COD and NH₄⁺-N were slightly decreased at the early stage of concentration increase, but after one week, they could reach above 80% and 99% respectively. However, when the S^2- concentration exceeded 100mg/L, filamentous bacteria would overgrowth and SVI >100mL/g, so the system would become instable.（3） The microbial population of aerobic granules for ammonium and sulfide removal was also studied. The PCR-DGGE analysis showed that: during stable operation, the microbial population of aerobic granules was comparatively rich and their structures were steady. The population mainly includedβ-proteobacterium and Uncultured Bacteroidetes bacterium, which accounted for 27.27% and 18.18%, respectively. Dominant consortium in granules were denitrifying bacteria （Thauera sp.）, Heterotrophic Nitrification Bacteria （pseudomonas alcaligenes）and Uncultured Thiothrix sp..（4） The removal process and influencing factors were studied. The nitrogen removal pathways including nitrification and denitrification, Simultaneous nitrification and denitrification and heterotrophic nitrification and denitrification in the SBR system. Sulfide was removed mainly through the biological oxidation processes of Uncultured Thiothrix sp.. DO had a great impact on the removal efficiency of ammonium and sulfide.（5） The reason why aerobic granules could keep a highly-efficient ammonium removal performance under high concentration of sulfide was also discussed. The sulfide removal mainly took place in the first 30 minutes of the cycle of the SBR, while ammonium removal in the range of 30-120min.The SBR reactor showed high removal capacity of NH₄⁺-N under the high S^2- concentration, which was possible due to the layered structure of aerobic granules or the characteristics that sulfide could be fast oxidized prior to the ammonium.（6） The mass transfer and kinetics of aerobic granules were also considered. The mass transfer of DO and sulfide showed more influence on nitrification and denitrifying, while the mass transfer of ammonium showed little. The kinetic models of aerobic granules for COD and NH4+-N removal were as follows:更多还原