【作者】 刘国文；

【导师】 张盼月； 胡茂中；

【作者基本信息】 湖南大学 ， 环境工程， 2007， 硕士

【摘要】 含氟废水主要来源于含氟矿石的开采加工、金属冶炼、铝电解、焦炭、玻璃、电镀、化肥、农药、化工等行业,浓度较高,对环境造成了污染。氟污染日益受到人们的关注,含氟废水治理技术的研究一直是国内外环境保护领域的主要课题。氨氮废水来源广,在化肥、炼油、无机化工、肉类加工、饲料生产、有色金属冶炼,以及农业、动物的排泄和日常生活的垃圾渗滤液中,都存在氨氮废水排放。氨氮废水对自然环境和人体都有较大危害。目前在我国,氨氮废水的处理仍是一个难题,对其治理技术的研究具有重大实际意义。钽铌冶炼加工企业排放的含氟含氨氮废水,是典型的高浓度含氟含氨氮废水,其处理一直是该行业中一个比较大的难题。笔者结合工作实践,通过对湖南省某钽铌冶炼加工企业的钽铌冶炼含氟含氨氮废水处理技术的探索,主持实施了该钽铌冶炼加工企业的钽铌冶炼含氟含氨氮废水治理工程,结合该废水治理工程实例,重点从方法与原理、工艺流程、技术参数、工程效果、经济性分析、存在问题与改进等方面作了系统的介绍,最后提出用电石渣沉淀除氟、吹脱除氨氮和生态氧化塘辅助脱氨氮的“组合处理法”对处理难度大的钽铌冶炼废水可实现有效治理。本工程中,除氟工艺考虑电石渣乳尽量过量,使pH值在11以上,搅拌反应时间30min,沉淀时间60min;实际操作中,采用“三级反应”模式,每级反应时间保证在10min以上,保证总反应时间在30min以上,然后流至辐流式沉淀池沉淀,沉淀时间在60min以上。吹脱除氨氮工艺选择pH值为11.0,将废水用蒸汽加热到50℃,吹脱气液比为3200;1（吹气量3380 m³/h）,吹脱时间为2h。生态氧化塘的辅助脱氨,就地取材利用该钽铌冶炼加工厂的污染防护带、面积90多亩的天然洼地作生态氧化塘来辅助处理废水,利用菌藻共生的作用处理废水中的有机污染物和无机氨等主要污染物,塘中的异养型细菌将水中的有机污染物降解成CO₂和水,氨氮作为菌藻生长的营养成分,同时也消耗水中的溶解氧;塘中藻类则利用太阳能进行光合作用,以CO₂中的碳源合成自身机体并释放氧气,使水质得到净化。本工程的设计处理能力350m³/d。在实施过程中,通过生产工艺改进,使废水量大大减少,实际处理量为200 m³/d左右,既节省了工程费用,也确保了处理效果。本治理工程分为氨吹脱系统、综合处理系统两大处理系统。该废水处理工程是国内对钽铌冶炼含氟含氨氮废水实施完整、系统处理的先例,通过处理,钽铌冶炼废水中的主要污染因子氟离子、氨氮去除率分别达到99.5%和94.7%,效果显著,环境效益突出,在国内钽铌冶炼加工行业中具有良好的示范作用。更多还原

【Abstract】 Fluorine-containing waste water mainly comes from fluorine ore exploration and processing, metal smelting, aluminum electrolyzing, charcoal, glass, electroplating, fertilizer, pesticide and chemical industry, etc. The high concentration of fluorine usually causes pollution to the environment. Fluorine pollution is inviting more and more attention from the public. The investigation on the treatment technology of fluorine containing waste water has always been the major topic of the environmental protection filed at home and abroad. Ammonia and nitrogen containing waste water comes from extensive sources including fertilizer, oil refining, inorganic chemical, meat processing, feedstuff production, nonferrous metal smelting, agriculture, animal excretion and daily garbage liquids etc. It is harmful to the natural environment and people’s health. In China, ammonia and nitrogen containing waste water treatment remains a problem. Therefore, this study of the treatment technology is of practical significance. The waste water discharged from the tantalum and niobium smelting and processing industry has a high concentration of fluorine, ammonia and nitrogen, and its disposal has been a problem in the industry.Based on his work experience, the author takes charge of carrying out the project of waste water treatment by probing into the treatment technology of fluorine and nitrogen containing waste water in a tantalum and niobium smelting plant in Hunan Province. This paper is focused on a systematic introduction of the approach, principle, technique process, technological parameter, engineering effect, economic analysis, existing problems and improvement measures in the light of the concrete examples of the project. Finally, a "combined treatment process" is proposed to effectively treat the waste water from the tantalum and niobium smelting industry, i.e., calcium carbide residue e-fluorine, blowing de-ammonia and nitrogen and ecological oxidation pond de-ammonia and nitrogen.In this project, the process of fluorine removing should be tried best to make the carbide slag water excessive and pH should be controlled above 11. Mixing reaction time is 30 min, and deposition time is 60 min. During the operation, three-stage reaction method will be adopted, each reaction stage should be controlled more than 10 min, and the whole reaction should be controlled more than 30min. Then it goes to basin radial sedimentation tank and the deposition time is more than 60 min. The pH of blowing de-ammonia and nitrogen process should be 11.0. Wastewater should be heated by steam to 50℃, blow-off gas liquid scale is 3200:1 （air blowing amount is 3380 m³/h）, and the blow-off time is 2h.The slave ammonia-separating of the ecological oxidation pond, using local materials of the pollution defending belt of the tantalum and niobium smelting and processing factory which is a natural marsh of more than 90 Mu, utilize the bacterium and alga communal function to deal with the main pollutants for example organic pollutants and abio-ammonia. Heterotrophy bacteria in the pond reduce the organic pollutant in the water into CO₂ and H₂O. Ammonia nitrogen as nutrition for bacterium and algae intergrowth also consume the dissolved oxygen in water. Algae in the pond utilize solar energy to make photosynthesis, and use the carbon from CO₂ to compose itself and release oxygen so that to purify the water.The designed treatment capacity of this project is 350m³/d. In the process of its implementation, the amount of waste water was greatly reduced because of the improvement of the production processes and the actual treatment amount was about 200m³/d. The project expenses were saved and the treatment effect was guaranteed. The project consists of two large treatment systems: the ammonia blown system and the multipurpose treatment system.This waste water treatment project is the first case of complete and systematic treatment of ammonia and nitrogen waste water in the tantalum and niobium smelting industry. The removal proportions of major pollution elements such as fluorine ions, ammonia and nitrogen reach 99.5% and 94.7% respectively after the treatment, bringing about an outstanding effect and prominent environmental benefits. This sets a good example in the tantalum and niobium smelting industry in China.更多还原