2000m3/d印染废水处理工程设计
致 谢
毕业设计是学生理论联系实际的桥梁，是对课本知识的扩展和补充,是体察工程实际问题复杂性、学习和工作的又一次尝试。本次设计使我充分认识到生产实际过程中的灵活性和多变性，设计中培养了我发现问题、解决问题的能力。在许中坚老师的精心指导下，我们从最初的茫然到后来对整个设计的了解，虽然遇到了很多的困难,也体会到了做设计的辛苦，但我们却收获了许多，不论在处理问题的方法上，还是在个人的实际能力上，都得到了很大提高。在许老师的帮助下，在我们的努力下，经过不懈努力，本次毕业设计顺利完成了。
在本次设计过程中，首先要感谢张勇老师的严格要求和耐心指导，老师严谨的治学态度、热忱的待人方式深深地感染了我，使我受益匪浅，在此，特向张老师表示最诚挚的敬意和最衷心的感谢。
最后，我要对四年来辛勤培养我的老师在此表示衷心的感谢，对评审本设计和参加论文答辩的老师表示诚挚的敬意，并感谢所有给予我帮助的老师和同学们！感谢在大学学习期间与我一起度过的所有老师和同学们，这段难忘的时光是我一生的财富。
由于时间仓促，知识有限，本设计难免存在不足之处，敬请各位老师批评指正，完善这个设计。谢谢！
46
南京师范大学学士学位论文
英文文献
Combined treatment of dyeing wastewater by a new sequential bicycling biological fluidized bed
XU Gong di
1 Introduction
Dyeing wastewater is a kind of industrial wastewater which is difficult to treat. It contains not only high concentrations of bigger molecules, egnitryl and amino compounds, but also a large amount of heavy metals, which are toxic composition for most of microorganisms. The removal of color is also a troublesome task. The study on the biofilm reactor showed that the diversity and the long food chain may bring the bacteria cultivated in a biofilm reactor a stronger ability to survive in this stringent environment . Sequential batch operation has been proved to help the bacteria to adapt different kinds of foods and then keep high activity.The bacteria cultivated under a controlled variation process have shown a stronger resistance to the dramatically changed loadings than thebacteria cultivated under a constant process. A treatment plan combining anoxic process with aerobic process became gradually prevalent in the treatment of the dyeing wastewater. Though this composite treatment process has been successfully used in some cases, there are some practical disadvantages, such as longer retention time, bigger area, etc . Likewise the threephases fluidized bed reactor is a versatile bioreactor in this regard, and has been successfully applied in the treatment of urban wastewater and industrial wastewater. In general, the performance of a threephase fluidized bed bioreactor largely depends on the performance and stability of the biofilm itself. Some important characteristics of the fluidized bed bioreactor have been validated. Many researchers have examined the effect of the shear on the biofilmdetachment rate. The shear is one of the main factors to control biofilm thickness. Improved homogeneity and uniformity may improve the operation
of FBBs. Some problems have arisen when the traditional fluidized bed is used in the treatment of industrial wastewater. It is difficult to control the thickness of the biofilm and separate the carriers from the effluent, which may cause the loss of the supporting
solids. A recently invented internal circulation biofluidized bed reactor can be used to control biofilm thickness. But some shortcomings exist, difficulty of separating the carrier from the effluent, complex structure and much resistance lead over much biofilmdetachment in some part. In order to solve these problems, a new wastewater treatment equipment, the external recycling biological fluidized bed, was developed for the treatment of dyeing wastewater and had better efficiency. It improved the
separation gassolid from liquid and reduced flow resistance. Whereas it was difficult for this equipment to remove color in dyeing wastewater, and the degradation efficiency for refractory or noxious organic chemicals was low because only the aerobic process was operated. The sequential batch operation, which cancombine anaerobic digestion and aerobic processes, is not easy to be adopted in this kind of fluidized bed.
Therefore a new sequential biexternal recycling biological fluidized bed (BRBFB) reactor system has been developed, which can be controlled automatically and applied to treat
47
2000m3/d印染废水处理工程设计
wastewater of high concentration and color. The BRBFB and its application in treating dye wastewater will be described and discussed in this paper.
2 Materials and methods
2.1 Apparatus
The fluidized bed is made of plexiglass and shown schematically in Fig. 1, which consists of a main bed and an auxiliary bed. The inner diameter and height of the main bed are 100 mm and 970 mm respectively,while those of the auxiliary bed are 200 mm and 770mm respectively. The total volume of the fluidized bed is 38 L. Granular activated carbon (GAC) is chosen as the microorganism carrier. The change between aerobic and anaerobic state and sedimentation, idle and discharge in this reactor is facilitated by an automatic control box. Five sets of different combinations of operating procedures are investigated in this study.
The wastewater used in this study is simulated as a type of typical effluent of a dyeing plant in Shanghai,China, which contains CMC ( sodium carboxymethyl cellulose), acidic red B, detergent powder, soluble starch, ammonium chloride, potassium diphosphate, and sodium bicarbonate, monobasic.
2.2 Analytical methods
Water quality was analyzed according to the Standard Chinese National Methods: CODCr ( MethodGB11914- 89); BOD5(Method GB7488- 87); pH (Method GB6920- 86); Color (Method GB11903- 89).
3 Results and discussion
3. 1 The gradient cultivation procedure for themicroorganism As the system was operated in frequent transformation among aerobic and anaerobic states and the wastewater contains a lot of toxic organics, the cultivation of the microorganism was difficult. In this study, the gradient cultivation method was used. Theactivatedsludge up to 30% of the total reactor volume was put into the fluidized bed, which was taken fromthe aeration tank in a local wastewater biological treatment plant. At the beginning, the nutrient solution with C N P = 200 5 1 was supplied in several periods, which was prepared from glucose, ammonium chloride, potassium diphosphate. After a couple of days, 10% of the nutrient solution was substituted by dyeing wastewater inexperiment and the removal efficiency of CODCr of the outflow was determined in every period till it reached up to 75%.Then the proportion of dyeing wastewater in the nutrient solutionwas raised to 30%,70% and 100% respectively. For all the cultivation period, both the anoxic and the aerobic processes were set to be accomplished in 8 h, sedimentation process in 1 h, discharge in 1 h, and idle process in 5 h respectively.It can be seen clearly that the removal efficiency decreases obviously at every beginning of the increase of influent CODCr due to the increase of the proportion of dyeing wastewater in this case. The removal efficiency can go up to 75% after several periods of cultivation and ascend to 80% at the end of the cultivation. The
48
南京师范大学学士学位论文
results indicate that microorganism has been accustomed to this environment which contains higher concentration of toxic dyeing wastewater and possessed the ability to resist the impact of changed loading.
3.2 The dosage of the granular activated carbon (GAC)
The dosage of GAC was tested from 0 to 20g/L for the influent CODCr of 510.2mg/L. the removal efficiency of CODCr increases dramatically from 53. 3% to 84. 6% as the dosage of the GAC increases from 0 to 10 g/L. Whereas it decreases slightly with the further increase of the dosage of the GAC from 10 g/L to 20 g/L. Because the increase of GAC causes the increase of biofilm in the reactor but overabundance of GAC induces the collisions between each other and results in biofilm detachment from the GAC. Therefore, the optimal dosage is 10g/L. In this case, the removal efficiency of color is over 90% .
3.3 The effect of circling flux to removal efficiency of CODCr
In order to ascertain the effects of circling flux on COD removal, the circling fluxes in anaerobic course were changed and the removal efficiencies of CODCr were measured after 4 h anaerobic and 4 h aerobic course when CODCr of influent was 502.6 mg/L. It is obvious that the optimal circling flux is 0.18m3/h and the highest removal efficiency is 84. 2% . In this case, the fluidized bed is in its best state as the
appropriate turbulence intensity gives the thickness of the biofilm on the surfaces of the carriers an optimal value and a higher mass transfer rate synchronously. The removal efficiency of CODCr declines with the further increase of the circling flux due to the enhancement of the turbulence intensity and the shear strength on the biofilm surface, which leads to excessive detachment of the biofilm. When circling flux further increases to 0.22 m3/h, the removal efficiency of CODCr drops markedly to72.3% .On the other hand, the removal efficiency of CODCr declines with the decrease of circling flux from 0. 18 m3/h since the renewal of the biofilm and mass transfer rate are slower because of lower shear strength. When the circling flux drops to0.12 m3/h, the removal efficiency of CODCr declines dramatically to 61.3?cause in this case the fluidized bed can not be fluidized normally and part of carriers are settling in the bottom of the fluidized bed
4 Conclusions
Gradient cultivation of the microorganisms was adopted in this study as the system was operated in a frequently changing mode. The results have demonstrated that the microbes of the selected cultivation have the stronger ability to remove CODCr in toxic wastewater. The optimal operation parameters were determined as follows: the dosage of GAC is 10 g/L,circling flux is 0. 18 m3/h and aeration quantity is 0.08 m3/h
.The best combined treatment for the dyeing wastewater is 4 h anaerobic process and 4 h aerobic process. The BRBFB has also strong ability for color removal. For a wastewater with a color of 250- 500, the color is decreased to 16 after 5 min and the
wastewater becomes colorless after 10 min. The color removal efficiency is close to 100% . Compared with previous results, the advantages of the combined treatment technology of BRBFB are obvious, such as shorter treating time, smaller space and no waste sludge to treat and so causes little secondary contamination.
49
2000m3/d印染废水处理工程设计
中文翻译
新型生物流化床处理印染废水的序批式组合工艺研究
徐功娣
1．介绍
印染废水是一种工业废水是难处理的工业废水。它包含不仅高浓度的更大的分子,氨基化合物,而且大量的重金属毒性成分,对大部份的微生物。除去颜色也是一个麻烦的任务。研究表明,生物膜反应器的多样化和漫长的食物链中可以提起细菌生物膜反应器培养能力较强生存在这个严格的环境。连续间歇操作已经被证明有助于细菌适应不同种类的食物,然后继续保持较高的活性。下一个被控制的细菌培养变化过程都表现出了较强的阻力，戏剧性地改变了载荷不变情况下培养细菌的过程。在处理印染废水，一个处理方案包含有氧过程结合缺氧过程是日益普遍的。虽然这一复合处理工艺已成功应用在一些案例里,但是仍有一些实用的缺点,例如长滞留时间、需要更大的面积,等等。同样的流化床反应器是一种用途广泛的生物反应器,在这方面,已成功地应用于处理城市污水和工业废水。一般来说,说明的性能很大程度上取决于流化床生物反应器的性能和稳定性的生物膜本身。一些重要的特性描述流化床生物反应器已经经过验证。许多研究人员检验了这个效果在生物过滤处理剪切率。剪切的主要因素之一是控制生物膜的厚度。改进的均匀性和均匀性可以改善操作。出现了一些问题时,传统的流化床用于治疗的工业废水。很难厚度的控制生物膜的载体,分离出水,这可能导致亏损的支持固体。最近发明了内部循环生物流化床反应器可用于控制生物膜的厚度。但是一些缺陷存在,困难的分离承运人从废水、结构复杂、多少阻力的领先优势在某些部分。为了解决这些问题,提出了一种新的污水处理设备,外部循环生物流化床,研制了适用于处理印染废水治理和最好的效率。它提高了从液体和降低分离流动阻力。而很难在这个设备清除颜色印染废水,并对耐火材料的降解效率很低，因为只有有氧过程操作了。序贯间歇操作,可以结合起来,厌氧消化和有氧过程,不易被采用在这种流化床。
因此,一个新的序列循环生物流化床(BRBFB)反应器系统已研发出可自动控制,并将其应用于高浓度废水处理和颜色。这BRBFB及其应用,在处理染料废水的描述,并在此基础上探讨了。
2材料和方法
2.1仪器
流化床包括主要的床和一个辅助的床。内在的直径及高度的主要床是100mm和970mm的分别,而那些辅助床是200mm和770mm分别。总容量的流化床颗粒状活性炭被选择作为微生物载体。之间的变化喜氧和厌氧状态和沉积、闲置和排放在这个反应堆由各行业自动控制盒。五套不同的组合,操作程序进行实验研究。分析中采用的废水进行了模拟是一个类型的典型废水的一种染色植物在中国上海,含有羧甲基纤维素钠(CMC)、酸性红B、洗衣粉、可溶性淀粉、氯化铵、钾磷、碳酸氢钠、一代。 2.2分析方法
根据水质标准分析了中国传统方法:CODCr-89);(MethodGB11914 GB7488-87BOD5(方法);pH值(方法);GB6920-86-89GB11903颜色(方法)。
50