【作者】 帅兴华；

【导师】 谢益民；

【作者基本信息】 山东轻工业学院 ， 制浆造纸工程， 2007， 硕士

【摘要】 造纸废水是我国水体污染的主要污染源之一,已成为制约我国造纸工业发展和水污染治理的瓶颈。由于废水排放量大,污染物浓度高,含有生物难降解的木素及其衍生物,常规的物理、化学、生物等处理手段很难保证日益严格的废水达标排放标准。尤其对于在数量上占有优势的中小型造纸企业,由于原料复杂、生产技术相对落后、工厂规模不够大,目前还没有经济、有效的废水处理技术。本论文提出了仿酶氧化结合絮凝法处理造纸废水的新工艺,先通过模型物和磨木木素的反应证实此仿酶反应能够氧化降解木素模型物及磨木木素,然后应用于处理废水的研究中,并成功用于造纸企业废水处理。本文首先合成了一种酚型的木素模型化合物(愈创木基丙三醇-β-愈创木基醚)。采用新方法成功地合成了愈创木基丙三醇-β-愈创木基醚化合物,用乙醇代替三氯甲烷和乙酸乙酯做反应溶剂,对关键的中间产物4-(α-溴代乙酰基)-愈创木酚的合成方法进行了改良,使其得率可以稳定的达到80%。利用红外光谱、核磁共振谱(1H-NMR)分析等手段对其化学结构进行了分析确认。本文利用合成出来的愈创木基丙三醇-β-愈创木基醚作为木素模型化合物。在采用Fe2+-羧酸复合物仿酶配位化合物(Fe-CA)/过氧化氢的仿酶体系对其进行仿酶降解处理后,利用核磁共振(13C-NMR)和GC-MS等分析手段对反应的产物进行了分析。研究发现:降解产物中含有了大量的羰基、羟基和羧基,从而有利于废水在阳离子絮凝剂的作用下絮凝脱除木素。本研究也阐明了这种β-O-4型的木素模型化合物的结构在Fe-CA/H2O2仿酶系统中分解反应机理,推断出该仿酶体系能有效导致酚型的β-O-4型木素模型化合物之间的降解反应。如:Cα-Cβ键的断裂、β-芳基醚键的断裂、Cα-Cβ键的断裂。Fe-CA/H2O2仿酶降解体系对蓝桉MWL的降解能力较强,降解后的羰基和羟基明显增多,这些基团的增加使木素与阳离子型无机和有机絮凝剂的亲和性增加。从而使废水中用普通絮凝方法难以絮凝的水溶性木素大量析出,废水的COD才能有比较大的去除率。造纸厂综合废水经Cu-吡啶、Cu-胺、Fe-CA三种仿酶体系处理,COD去除率分别可达72.2%、71.8%和75.1%。通过对比三种不同的仿酶体系,我们发现Fe-CA/H2O2仿酶体系处理效果最佳。通过研究发现,Fe-CA/H2O2仿酶体系处理废水的最佳条件为:用量0.02mmol/L废水,原水pH值需调至中性,废水温度不低于30℃。中试结果显示应用Fe-CA/H2O2仿酶处理系统可以很好的处理木素含量较高的制浆造纸中段废水,其最佳条件为:Fe-CA仿酶用量0.02mol/m3,双氧水用量150g/m3,硫酸铝的投加量为300g/m3,CPAM加入量为5g/m3,处理时间30分钟,沉降时间6个小时。根据本研究的工艺条件,我们设计出仿酶处理体系处理废水工程,应用于山东省某造纸企业(含麦草半化学浆生产线),并经过连续一个月的运行,达到很好的CODCr、SS去除效果。采用仿酶氧化-混凝法处理高CODCr的造纸厂综合废水,CODCr、SS等主要污染物的去除率分别可达55%、60%以上,通过木素的大量脱除有效地提高了废水的可生化性,为难降解废水的后续处理创造了条件。该处理工艺设备简单,操作方便,成本低,可以适应较高的废水负荷。更多还原

【Abstract】 As one of the main pollution sources of waters, pulping and papermaking effluent has become a bottleneck in the development of papermaking industry. This kind of wastewater has characteristics of high concentration organic substance, abundant lignin and other polyphenols which are difficult to be decomposed by microbe. Therefore it is very hard to treat with conventional methods for wastewater treatment, such as physical or chemical or biological treatment. By now, there is not very effective technology of treating pulping and papermaking wastewater, especially for middle-scale factories, because of the non-wood fiber material, low technology and small scale. In this paper, a novel biomimetic flocculation method was developed. It was confirmed that the biomimetic oxidation could degrade lignin model. The biomimetic flocculation was also used to treat wastewater of paper mill, and it obtains great success.In this paper, a model compound ofβ-O-4 type lignin model compound (i.e. guaiacyglycerol-β-guaiacyl ether) was synthesized with a modified method. The synthesis method of an impant intermediate,i.e. 4-(α-bromoactyl)-guaiacol was improved, Its yield reached 80%. The combination of infrared spectra, 1H-NMR analysis was used to identify the chemical structure of the product and related precursors.The lignin model compound of guaiacylglycerol-β-guaiacyl ether was treated with a Fe-carboxyl acid complexes (Fe-CA)/H2O2 biomimetic system. The reaction products were analyzed by 13C-NMR and GC-MS. The mechanism of the biomimetic degradation of thisβ-O-4 structure was also explored. It was found there were a lot of carbonyl, carboxyl and hydroxyl groups in the degraded products. It was proved that the following three types of reaction were caused by the Fe-CA/H2O2 system:β-aryl ether cleavage, Cα-Cβcleavage, Cβ-Cγcleavage. It was found that Fe-CA/H2O2 biomimetic system could deeply degrade MWL from Eucalyptus globules. Carboxyl, carbonyl and hydroxyl group increased significantly. That can increase the proximity between degraded lignin and cationic inorganic or organic flocculate. As a result wastewater COD will be decreased greatly.A stable and high efficiency Fe2+-carboxyl acid complexes (Fe-CA) which could simulate the lignin peroxidase to treat the paper mill wastewater by quickly oxidation and flocculation treatment. As compared with Cu-pyridine biomimetic system and Cu-amine biomimetic system, the Fe-CA biomimetic system was more effective. Furthermore effect of biomimetic dosage, pH, temperature on wastewater treatment was investigated respectively. According to the experimental results and condition of a middle-scale paper mill, an integrated treatment process was designed and optimized. The optimal coagulant and its actual application parameters of coagulation for the wastewater were acquired by pilot experiment. The optimal condition was as follow. Fe-CA 0.02mol/m3; H2O2 150g/m3; Al2(SO4)3(18H20) 300g/ m3; CPAM 5g/m3; 30min reaction time and 6h sedimentation.Based on the results stated above, a mill scale Fe-CA biomimetic flocculation process was developed for the mixed wastewater treatment of a paper mill in Shandong Provice. The design of the biomimetic flocculation system was also carried out in our research group. After one month continual operation, very good COD and SS elimination effect was achieved. The elimination rate of main pollutant such as CODCr and SS reached above 55%, 60% respectively. Through lignin massive removing, the effect of subsequent biochemical was also enhanced. The process have merit of simple equipment, easy operation and low cost. It is also suitable for treatment of heavly duty effluent.更多还原