【作者】 杨禹；

【导师】 王鹏；

【作者基本信息】 哈尔滨工业大学 ， 环境科学与工程， 2009， 硕士

【摘要】 青霉素生产废水中含有大量的抗生素,发酵残余基质及营养物、溶媒提取过程的萃取液、水中不溶性抗生素的发酵滤液、发酵产生的微生物丝菌体,具有COD值高（10000～80000mg/L）、BOD/COD （B/C）值低、难降解的特点,能够抑制微生物的生长,给废水处理带来极大的困难。本文针对青霉素生产废水中可生化性差、难降解的问题,研究开发了酸析—微波强化Fenton混凝处理工艺,并对微波强化Fenton混凝体系的反应机制进行了初步探讨。在酸析预处理工艺中,调整pH为4-5,静沉过滤后测定溶液中COD值,去除率达到70%左右（由172587mg/L降至49912mg/L）。将酸析处理后出水进行微波-Fenton混凝预处理,考察各工艺参数对去除效果的影响,获得最佳工艺条件如下:在初始pH为4.5-5的条件下,加入4900 mg/L Fe₂（SO₄）₃,1300 mg/L H₂O₂,在微波功率为300W的条件下辐照6min,,COD和UV₂₅₄的去除率分别达到57.53%和55.06%。B/C从初始的0.165提高到0.470。对微波在处理工艺中的作用进行了系统研究,比较相同反应条件下微波-Fenton、水浴-Fenton、常温-Fenton处理青霉素生产废水的效果,实验表明微波-Fenton体系处理后COD去除率略有提高,达到57%。B/C为0.47,较水浴-Fenton体系高出0.177,较常温-Fenton高出0.094,微波的加入有利于提高Fenton混凝体系的处理效果。利用高效液相色谱考察反应前后分子量分布变化,大分子有机物和小分子有机物均得到大量去除。采用透射电子显微镜考察絮体结构,所有的颗粒之间连接得非常好,并呈网状结构。采用Ferron逐时络合光度法分析不同反应条件下Fe³⁺水解产物的形态分布。实验结果表明,在功率为300W的条件下,产生Fe（c）的含量最多,达到72.61%,说明适当的微波作用有利于促进体系中高聚态铁的生成。对照微波与水浴加热下铁的水解产物,发现在相同温度条件下,微波作用产生更多的Fe（c）,较水浴条件下高出25%。此外,不同pH下铁的水解形态有很大差异,强酸条件下铁的水解产物以Fe（a）为主,随着pH的增大,Fe（c）的含量增多。更多还原

【Abstract】 There are a large deal of antibiotics exist in penicillin production wastewater, as well as residual substances and nutrient of fermentation, extracting liquid of solvent extraction, insoluble antibiotics of fermentation filtrate and microorganism cells generated in fermentation. This kind of wastewater is characterized by high COD （10000⁸0000 mg/L）, low BOD5/COD （B/C） ratio and bad biodegradability, which is hard to be treated due to its inhabitation to the growth of microorganisms.Under the context, the present work focused on the investigation of microwave enhanced Fenton-coagulation process for the pre-treatment of high concentration penicillin production wastewater. It is aimed to optimize the operating conditions and explore the mechanism of the effluence of microwave on coagulation system.During the experimental runs of acid precipitation, by adjusting the pH in the range of 4 to 5, the load of COD in supernatant decreased from 172587 mg/L to 49912.5 mg/L, resulting in 70% of COD removal was achieved. Then, the effluent was treated by means of Fenton-coagulation. The operating parameters of microwave enhanced Fenton-coagulation process for treatment of penicillin production wastewater were examined, and the optimal conditions were as follows: microwave power was 300 W, radiation time was 6 min, initial pH was 4.45 to 4.5, the dosages of Fe₂（SO4_）3 and H₂O₂ were 4900 mg/L and 1300 mg/L, respectively. Within these conditions used, the removal ratio of COD and UV₂₅₄ were 57.53% and 55.06%, respectively. Meanwhile, the value of B/C ascended from 0.165 to 0.470. By comparing the results of microwave-Fenton, water bath-Fenton and ambient temperature-Fenton for the treatment of such wastewater under the identical conditions, the B/C of microwave-Fenton was 0.470, which was higher than both of two other processes （0.293 for water bath-Fenton and 0.376 for ambient temperature-Fenton）. Therefore, it was believed that microwave was favorable to the enhancement of removal efficiency of Fenton-coagulation system.The variation of molecular weight distribution between pre and post treatment were monitored by means of high performance liquid chromatograph. The result suggested that a large amount of both macromolecular and micromolecular organic compounds were eliminated. The structure of flocs was observed with transmission electron micrograph. It displayed a fine linkage between each particle to form a layer-like structure. A ferron-complexation timed spectrophotometric method was used to examine the hydrolysates of Fe³⁺ at different reaction conditions. When microwave power was set at 300 W, the generated Fe（c） reached its maximum, accounting for 72.61% of total ferric, suggesting that proper microwave power was successful to promote the formation of high polymeric ferric species. On the basis of comparative results of microwave and water bath heating, at the same temperature, Fe（c） generated in the former procedure was 25% more than that of latter. Furthermore, the distribution of ferric hydrolysis species was of evident difference at different pH. In the strong acid, the main product is Fe（a）. As the increase of pH, the amount of Fe（c） increased gradually.更多还原