浅谈城市污水处理工艺-CASS工艺毕业论文方案.doc

毕 业 实 习 题 目： 学 院： 环境科学与工程学院 专 业： 学 号： 学生姓名： 指导教师： 2015年4 月15 日 摘 要 在维系人的生存，保障经济建设和维护社会发展的所有自然要素中，水的重要性毋庸赘述，然而随着工业化、城市化进程的加快，全世界都面临着水资源短缺，污染严峻的挑战。而在中国尤为严重。我国作为一个新兴的发展中国家，最近几十年，随着经济的发展，环境问题也日益严峻。许多城市水污染事故频繁发生，也使得我国本来十分严峻的水资源供给形势更加严峻。目前中小城市的污水排放量约占全国污水排放总量的一半以上，未来城镇建设的快速发展会使得污水排放量大幅增加，势必会加剧水环境的恶化。且城市污水是一种混合污水，须经处理达到相关排放标准才能排放水体，避免造成水体污染，故污水处理厂处理水再利用时，应按照使用目的执行相应的标准，确定相应的废水处理深度工艺。污水的资源化、污水的再生利用，既提高了水的利用率又有效地保护了环境，有利于实现城市水系统健康、良性循环。是解决水资源短缺，水污染的有效途径。本文较详细的介绍了几种生化处理工艺，比较了它们各自的优缺点，并根据实际情况选择了合适的处理工艺。最终选择CASS工艺来处理城市生活污水。 关键词：城市污水 处理工艺 CASS工艺  Abstract In maintaining peoples survival, protection of economic construction and maintenance of all natural elements of social development, the importance of water needless to say, however, with the speeding up of industrialization and urbanization, the whole world is facing water shortage, pollution serious challenges.And in China particularly serious.In China as an emerging developing countries, in recent decades, with the development of economy, environmental problems are increasingly serious.Many cities water pollution accidents occur frequently, also makes our country have serious water supply situation is more serious.The sewage of small and medium-sized cities which accounts for more than half of total sewage discharge, the rapid development of the future urban construction will make wastewater emissions increased dramatically, will aggravate the deterioration of water environment.And urban wastewater is a kind of mixed sewage, related emission standards must be approved by processing achieve to discharge water, avoid to cause water pollution, so the water recycling, sewage treatment plant should be in accordance with the purpose to perform the corresponding standards, determine the corresponding depth of the wastewater treatment process.Utilization o