【作者】 胡梅芬；

【导师】 李小明； 曾光明；

【作者基本信息】 湖南大学 ， 环境科学， 2005， 硕士

【摘要】 随着我国经济的发展和城市化水平的提高,城市污水排放量逐年增加。高效厌氧技术作为一种具有节约能耗和投资、回收能源、产生的剩余污泥少等优点的技术,对经济尚不够发达而污染亟待治理的我国,尤其是绝大多数没有污水处理设施的小城镇,在城市污水的处理方面显示出了很强的吸引力。 近二十年来,国内外学者通过动力学理论的研究,认识到厌氧工艺中提高污泥龄和水力停留时间(SRT/HRT)比值的重要意义,并随着对颗粒污泥和生物膜等生物固定技术的深入了解成功开发出了一系列的高效厌氧工艺,使得厌氧技术在较高温度下处理城市污水取得了巨大的成功,但将厌氧城市污水处理工艺在热带地区成功的经验,扩大到亚热带和温暖气候地区仍然面临着重大挑战。 本课题立足于国内外厌氧处理低浓度污水的最新研究成果,以普通活性污泥接种,在上流式厌氧污泥床反应器(UASB)中处理低浓度污水培育颗粒污泥。在成功培养颗粒污泥的基础上,研究两步AF+AH系统在亚热带气候下对实际城市污水的处理效果及可行性。 研究结果表明,UASB反应器中,在中低温度下(25～9℃),即使进水浓度低至100～200mgCOD/L,仍能在两个月内形成成熟的颗粒污泥,颗粒的平均粒径大于0.5mm,沉降性能好,污泥体积指数(SVI)在23.4～27.7ml/g之间;颗粒污泥的比产甲烷活性(SMA)随培养条件的不同差异较大:进水浓度100～200mgCOD/L,35℃下形成的颗粒污泥的SMA最高,为0.23gCOD/(gVSS·d);而室温(25～9℃)下形成的颗粒污泥产甲烷活性最低,仅为0.05gCOD/(gVSS·d)。将不同条件下形成的颗粒污泥混合接种至两步AF+AH系统中处理实际的城市污水,试验表明:该系统的AF部分能有效截留及水解城市污水中的悬浮性物质,提高进水的溶解性和可生化性。AH反应器中的颗粒污泥是生物降解的主体,能去除进水中33.9～93.5%的COD,其中平均有70.3%转化为甲烷,但能以气体形式回收的只占甲烷总产量的65.5%。两步AF+AH系统稳定运行情况下总的COD去除率在47.6%～98.1%之间,室温下、25℃和30℃时的平均去除率分别为77.4%、89.1%和93.5%。 研究表明亚热带气候下低浓度污水的厌氧处理中能在60天内形成颗粒污泥;以颗粒污泥接种的两步AF+AH系统对于处理城市污水十分有吸引力,即使在很低的温度和很短的HRT下也能取得高的有机物去除效果,并且产生的剩余污泥少且稳定,但对于营养物质的去出效果十分有限。更多还原

【Abstract】 Rapid urbanization and economic development in China has led to the annual increase of quantity of discharged municipal wastewater. Therefore, it becomes more and more important to develop appropriate wastewater treatment process, which combines high treatment efficiency with low capital investment, maintenance costs and simple operation requirements, especially in most of small cities and towns. Anaerobic treatment technology is an attractive alternative process for small communities wastewater treatment because its advantages including lower energy consumption, lower investment, operation and maintenance costs, little sludge production and energy recovery in the form of biogas and etc. It seems to be an ideal and sustainable solution for water environmental protection.Over the last two decades, researchers all around the world have realized the significance of the high ratio of SRT/HRT by the studying on the dynamics theories, and developed a series of advanced anaerobic reactor systems along with the deep understanding of the biology fixation technologies such as sludge granule and biofilm. Although the anaerobic treatment of domestic sewage has been applied on a large scale in several tropical countries (many as UASB reactors) with great success, the process is so far not applied on a full scale in sub-tropical countries. It’s a big challenge to extend the experiences from tropical areas to sub-tropical and moderate climate areas.In this paper, based on the newest relevant research results, we researched the granulation process in UASB reactors which treating very low strength wastewater, inoculated with digested sludge. Then, a feasible municipal wastewater treatment process, the AF+AH system, seeding with the granular sludge we had cultivated, was developed and the process performance was discussed.It shows that the sludge granulation can be realized in about two months even the influent concentration low as 100-200mgCOD/L at ambient temperature(25-9℃) in UASB reactors. The average diameter of the granule is more than 0.5mm. The SVI of the granule is between 23.4 to 27.7 ml/g, means good settlebility. The SMA of the granule is 0.05-0.23gCOD/(gVSS.d), depending on the used temperature and influent concentration. The granule growing in the wastewater of 100-200mgCOD/L and at the temperature of 25-9℃ has the lowest SMA of 0.05 gCOD/(gVSS-d).The AF+AH system was used to treat the real sewage seeded with the mixture of更多还原