【作者】 刘伟京；

【导师】 钟秦；

【作者基本信息】 南京理工大学 ， 化学工程与技术， 2013， 博士

【摘要】 印染废水具有水量大、有机物含量高、成份复杂、生物难降解等特点,印染废水处理技术一直是世界各国研究的重点课题。本论文采用“强化厌氧水解-A/O(PACT)+混凝沉淀过滤”组合工艺,研究处理以纺织印染企业为主的工业园区综合废水,达到江苏省《太湖地区城镇污水处理厂及重点工业行业主要水污染物排放限值》(DB32/1072-2007)要求。研究重点：(1)通过模拟水流状态,改进折流式厌氧反应器(ABR)结构,强化泥水混合效果,提高厌氧处理难降解有机污染物的效率。(2)系统优化水处理工艺流程和工艺参数,提高难降解有机污染物和氮磷去除率,降低废水排放毒性。(3)运用GC-MS分析手段,研究印染废水中有机污染物主要成分,及其在水处理流程中的迁移演变,对比不同水处理工艺对难降解有机物的去除效率,分析尾水和污泥中难降解有机污染物残留情况。(4)探索性研究电化学氧化去除残留典型特征污染物,有效削减尾水中易造成膜污染和膜堵塞的累积性物质,破解膜技术在印染废水回用工程中应用的技术瓶颈。上流式厌氧反应器(UASB)和折流式厌氧反应器(ABR)处理印染废水实验研究。结果表明在厌氧反应器水力停留时间为24h条件下,进水COD平均浓度755mg·L-1, UASB和ABR出水COD平均浓度分别为409.3mg·L-1和420.9mg·L-1,平均去除率分别为45.5%和43.9%。两种厌氧反应器对色度去除效果较好,进水平均值342倍,出水平均值分别78倍和80倍,平均去除率分别为77.2%和76.6%。印染废水B/C由0.29分别提高到0.46和0.43,废水可生化性明显改善。为发挥ABR反应器在处理难降解、毒性有机物方面的优势,进一步提高其处理效率,利用Fluent软件对ABR反应器的水流状态进行数值模拟,发现反应区内存在较为严重的短流及旋流现象,导致污泥流失,降低处理效果。本研究提出优化集水堰布置方式、在反应室底部配水区增设分流挡板等改造措施,改善反应区上升流态。模拟显示,改造后的反应器上部上升流速较小,且沿断面呈均匀分布,有利于截留污泥。在反应器中部形成三个较为强烈的涡流区,增强泥水混合效果。中试验证表明,反应器处理效率和抗冲击负荷能力均有较大提高。强化厌氧水解+A/O(PACT)+混凝沉淀过滤工艺处理印染废水中试研究与工程应用。中试系统稳定运行70d,进水COD最高值为1060.0mg·L-1,最低值为617.7mg·L-1,平均值为765.1mg·L-1,在水质波动较大的情况下,厌氧出水COD平均值为399.6·-1,COD去除率平均值为45.6%。A/O(PACT)出水COD平均值为105.2mg·L-1,过滤池出水COD平均值为51.3mg·L-1,系统COD总去除率平均值为93.2%。进水色度平均值为354倍,出水色度平均值为22倍,系统色度总去除率平均值为93.9%。气质联用(GC-MS)检测显示,组合工艺降低了印染废水累积性有机污染物的排放。运用该工艺建设了20000m3·d-1印染废水处理工程,各项指标均达到江苏省《太湖地区城镇污水处理厂及重点工业行业主要水污染物排放限值》(DB32/1072-2007)要求,通过当地环保部门的验收。运用GC-MS研究分析印染废水处理工程中有机污染物的迁移演变。分析了“物化+生化”和“生化+物化”2种印染废水深度处理工艺中有机污染物的降解过程,对物化污泥和尾水受纳水体中有机污染物进行了检测,从有机物降解效率的角度,比较2种工艺的优缺点。结果表明两中工艺的代表性工程中,“物化+生化”工艺对有机物的降解效果不如“生化+物化”,主要是两项工程厌氧水解效率有较大差异。此外,“物化+生化”工艺污泥产生量大,有机污染物降解不充分,部分有机污染物从废水转移到物化污泥,容易产生二次污染。电化学氧化技术深度降解印染废水生化出水的累积性特征有机污染物(二氯对苯二胺)实验研究。对线性极化曲线和循环伏安曲线进行分析,系统考察了电流密度、溶液初始pH值和二氯对苯二胺初始浓度对电催化降解二氯对苯二胺的影响。对二氯对苯二胺降解动力学研究表明,电催化降解二氯对苯二胺的过程遵循动力学一级反应。研究了电催化氧化降解二氯对苯二胺降解机理,采用紫外可见分光光度计,离子色谱和气质联用分析了电化学降解中间产物,提出二氯对苯二胺的电催化降解路径,表明电催化氧化作用可以有效降解特征污染物二氯对苯二胺。更多还原

【Abstract】 The printing and dyeing wastewater has large volume and complex substances, and contains many organic pollutans, which has toxicity and poor biodegradability. Treatment of printing and dyeing wastewater is a significant environmental concern. A pilot scale study of the treatment of printing and dyeing wastewater was carried out using the combined process of anaerobic-anoxic/oxic(PACT)-coagulation sedimentation to reach the discharge standard of main water pollutants for municipal wastewater treatment plant&key industries of Taihu area (DB32/1072-2007). In this thesis, the main research contents include:(1) The numerical simulation of flow pattern in anaerobic baffled reactor (ABR) used in wastewater treatment was carried out to strengthened sludge and wastewater mixing. After reconstruction using the above measures, the treatment efficiency of the reactor were improved.(2) Systematic optimization of the wastewater treatment process and operating parameters to improve the removal efficiency of refractory organic pollutans and decrease the wastewater toxicity.(3) GC-MS was used to determine the degradation process of organic pollutants in the treatment processes and compare the testing results of refractory organics removal efficiency in different treatment processes.(4) Exploratory research on removal of residual model organics by electrochemical oxidation was carried out to removal the residual organics causing membrane pollution in tail water and bread through the technical bottleneck in membrane filtration for the application ofengineering reuse of printing and dyeing wastewater.A pilot-scale study was conducted on the upflow anaerobic sludge blanket (UASB) and ABR for the treatment of printing and dyeing wastewater which has poor biodegradability. With the optimal hydraulic retention time (HRT) of24hours, the experimental anaerobic reactor UASB and ABR was steadily operated for two months. In the case of mass concentration COD with large variation in the influent, the final mean concentrations were409.3mg·L-1and420.9mg·L-1in the effluent from the UASB and ABR, respectively. The mean removal rates were45.5%and43.9%, respectively. When the mean influent color was342times than normal, the mean final effluent colors were78times and80times than normal for UASB and ABR, respectively. The removal efficiencies were77.2%and76.6%, respectively. The BOD5/COD ratios of printing and dyeing wastewater increased from0.29to0.43and0.46for UASB and ABR, which were raised0.17and0.14respectively. The biodegradability of wastewater was greatly improved. The numerical simulation of flow pattern in anaerobic baffled reactor used in wastewater treatment was carried out. The results found that serious short flow and vortex flow existed in the reactor, which led to sludge loss and poor treatment efficiency. Improvement methods of the flow pattern were proposed, including optimizing the wastewater weir layout and adding flow diversion baffle in wastewater distribution zone at the bottom of the reactor. The simulation showed that the flow velocity was small and evenly distributed along the cross-section in the upper part, contributing to the sludge retention. Three relatively strong central vortexes were formed in the middle, which strengthened sludge and wastewater mixing. After reconstruction using the above measures, the treatment efficiency and the shock load resistance of the reactor were improved.A pilot-scale study of the treatment of printing and dyeing wastewater was carried out using the combined process of anaerobic(hydrolysis)-aerobic-advanced treatment. The result of the experiment, which was operated stably for70days, are as follows:by varying and changing the printing and dyeing wastewater (maximum COD1060.0mg·L-1, minimum COD617.7mg·L-1, mean COD765.1mg·L-1), the mean final effluent concentration of anaerobic was399.6mg-L"1with removal efficiency45.6%; the mean final effluent concentration of aerobic was105.2mg·L-1with filtration effluent concentration of51.3mg·L-1; the total COD removal efficiency was93.2%. When the influent color was354times, the mean final effluent color was22times and removal efficiency was93.9%. The GC-MS analysis show that the the organic pollutant were effectively degraded by the combined process.In order to analyze the advantages/disadvantages of the combined treatment process between "physicochemical+biochemica"and "biochemical+physicochemical" in the treatment of textile wastewater, GC-MS was used to determine the degradation process of organic pollutants in this two totally different treatment processes. The same analysis was also conducted to the sludge and discharged water. The results showed that the "physicochemical+biochemical" process displayed a poorer effect than "biochemical+physicochemical" in degrading the organic pollutants. The difference was mainly manifested in the efficiency of anaerobic hydrolysis in the two coupled processes. Moreover, the implement of "physicochemical+biochemical" process resulted in the migration of plenty of typical organic pollutants to sludge from primary coagulation sedimentation process and to the discharged water, which would cause secondary pollution easily.Electrochemical degradation of the model organic pollutans2,5-dichloro-1,4-phenylenediamine (DP) in aqueous solution was investigated. Linear sweep voltammograms and cyclic voltammograms were studied. The influence of operating parameters on electrochemical oxidation of DP was studied as a function of the current density, initial pH and initial concentration of DP. The degradation kinetics analysis indicated that the electrochemical degradation of DP followed a first-order reaction. The degradation intermediates during electrochemical oxidation were analyzed by UV-vis spectrophotometer, ionic chromatograph (IC) and gas chromatography/mass spectrometry (GC/MS). The electrochemical oxidation of DP resulted in the release of NH4+and Cl". Based on these results, a degradation mechanism for electrochemical degradation of DP was proposed. It was concluded that the DP were effectively removed in the electrochemical treatment.更多还原