【作者】 蒋丽娟；

【导师】 王光华；

【作者基本信息】 武汉科技大学 ， 化学工艺， 2011， 硕士

【摘要】 我国钢铁生产过程中耗水量极大,特别是伴随着炼焦工艺所产生的大量焦化废水。焦化废水含有大量的对环境和人类健康有害的却难以降解的多环芳烃,若不处理而直接排入环境中,产生的危害是难以估量的。我国吨钢耗新水量和外排废水量与国际的先进技术相比仍存在着很大的差距,因此提高我国钢铁企业特别是炼焦行业的水资源综合利用率和外排水的再生利用率,将对我国水资源合理利用、经济的稳定而快速地发展和社会和谐发展具有举足轻重的现实意义。焦化废水中含有大量“三致”和难降解的组分——的多环芳烃,因此处理焦化废水的关键是低耗能和无二次污染的绿色环保技术。萘类和喹啉类是焦化废水中百分含量最高的多环芳烃类化合物,以此两类物质为对象研究微生物降解,对焦化废水的深度处理和再生循环利用具有着重要意义。生物活性炭(BAC)水处理技术作为一种绿色水处理技术在微污染废水和工业废水深度处理有着广泛地应用,但在焦化废水的深度处理的回用的应用研究却鲜见报道。本课题就是根据BAC工艺特性,研究萘和异喹啉多环芳烃类可微生物降解性、生物活性碳工艺在焦化废水深度处理工艺中的实用性、可行性和优越性,为后续的研究和焦化废水的循环回用提供理论依据。研究结果表明:(1)本实验成功从焦化厂土壤和曝气池活性污泥中通过富集、驯化和纯化等实验,成功地筛选出以萘和异喹啉分别为唯一碳源的菌株N-3和菌株K-4,对底物萘和异喹啉分别具有最高去除率和菌株生长量;并为后续的生物活性炭试验提供高效降解微生物。(2)根据高效降解菌株N-3的生理生化特性及16Sr DNA序列分析结果,鉴定菌株N-3为枯草芽孢杆菌Bacillus subtilis,其GenBank序列号是AEHM01000002.1。(3)根据高效降解菌株K-4的生理生化特性结果,初步确定菌株K-4为Pseudomonas。(4)采用单独投加高效降解菌混合液、GAC-3型活性炭和生物活性炭分别处理焦化废水二沉池出水。经过72h处理,生物活性炭对CODcr去除率分别比GAC-3型活性炭和高效微生物提高了17.80%和61.61%;色度去除率分别提高了2.2%和89.41%,满足中水回用标准。经过15次重复处理,生物活性炭对CODcr平均去除率分别比GAC-3型活性炭和高效微生物分别提高了11.90%和86.08%;色度平均去除率分别提高了26.6 %和79.02%。生物活性炭显示出其在深度处理回用焦化废水的优越性和可行性。(5)高效降解微生物与活性炭共同研制出的生物活性炭装置对模拟废水中的有机物具有较好去除率并稳定在60%左右。(6)生物活性炭上的高效降解微生物经循环泵入高效降解混合菌悬液和营养水,均匀、紧密地附着、生长在活性炭表面并形成具有降解性能的生物膜。生物活性炭上的生物量随着碳层高度的增加呈现下降的趋势;装置的试验最终出水中OD值呈现先上升后下降,并趋于稳定。生物活性炭吸附降解模拟废水中的有机物的动力学模型符合一级动力学模型,InC=-0.0318t+6.0143。更多还原

【Abstract】 A enormous amount of water is consumed in our steel production process, especially the coking wastewater accompanied by coking production process. Coking wastewater contains lots of polycyclic aromatic hydrocarbons (PAHs) which is harmful for environment and human health. If the coking wastewater is directly discharged into emvironment, the generated hazard will be inestimable. There are still a large gap in our per ton steel fresh water consumption and efflux, comparing with the international advanced technology. Therefore, improving steel enterprises, especially coking industry, comprehensive utilization of water resources and recycling rate of outer drainage will have important practial significance on rational use of water resources, steady and rapid economic development and harmonious development of society.There are plenty of leading to mutagenesis, carcinogenesis and teratogenesis and refractory components, PAHs, in the coking wastewater, so the key to treating coking wastewater is low energy consumption and green technologies without secondary pollution. Naphthalenes and quinolines are the highest percentage of PAHs in the coking wastewater. It play important role in coking wastewater advanced treatment and regeneration recycling utilization.Biological activated carbon (BAC) as a kind of green water treatment technology has been widely used in micro-polluted water and industrial wastewater treatment, but rarely reported in coking wastewater advanced treatment and regeneration recycling utilization. This research is based on BAC technology characteristic, studying in naphthalene and isoquioline biodegradability, BAC’s practicality, feasibility and superiority in coking wastewater advanced treatment technology and providing theoretical basis for the follow-up research and coking wastewater recycling utilization.Research results show that: (1)The experiment successfully has separated high efficiency degradation strains (HES) respectively named N-3 and K-4 as naphthalene or isoquinoline the unique substrate from the coking plant and aeration tank activated sludge through enrichment, domestication and purification. The high efficiency degradation strains provide with microorganism in the following BAC experiments. (2)According to the HES N-3 physiology and biochemistry 16Sr DNA sequence analysis experiment result, the strain N-3 is identified as Bacillus subtilis, which GenBank sequence number is AEHM01000002.1. (3)Accoeding to the HES K-4 physiology and biochemistry experiment result, the strain K-4 is initially identified as Pseudomonas. (4)The HES, GAC-3 and BAC are respectively applied to ttreating sedimentation tank effluent of coking process. After treatment for 72h, the removal rate of COD by BAC was 17.80% higher than GAC-3 and 61.61% higher than HES; the removal rate of chromaticity by BAC was 2.2% higher than GAC-3 and 89.41% higher than HES. The treated water by BAC can reach the renewable water stanedard. After reduplicative treatments for 15 times, the average removal rate of COD by BAC was 11.90% higher than GAC-3 and 86.08% higher than HES; the average removal rate of chromaticity by BAC was 26.6% higher than GAC-3 and 79.02% higher than HES. The BAC showed the superiority and feasibility in coking wastewater advanced and regeneration recycling treatment. (5)The BAC device jointly researched and produced by HES and GAC-3 had a good removal rate of organic matter in simulated wastewater, steadily around at 60%. (6)The high efficiency degradation microbe on the BAC was circularly pumped though high mixed efficiency bacteria and nutritive water, uniformly and closely attached and grew on the carbon surface and formed the degrading biomembrane. The biomass on the BAC is lower along with higher carbon layer. The BAC device final effluent OD value increased at first then decreased, stabilized at last. The BAC adsorbed and biodegraded the organic matter in simulated wastewater kinetic model fit first level kinetic model,InC=-0.0318t+6.0143.更多还原