催化臭氧化-生物组合工艺深度处理煤制气废水效能的研究

1、催化臭氧化-生物组合工艺深度处理煤制气废水效能的研究 博士学位论文 催化臭氧化-生物组合工艺深度处理煤制气 废水效能的研究 RESEARCH ON EFFICIENCY OF ADVANCED TREATMENT OF COAL GASIFICATION WASTEWATER BY CATALYTIC OZONATION INTEGRATED WITH BIOLOGICAL PROCESS 庄海峰 哈尔滨工业大学 2015年7月 国内图书分类号：TU992.3 学校代码：10213国际图书分类号：628.3 密级：公开 工学博士学位论文 催化臭氧化-生物组合工艺深度处理煤制气 废水效能的研究

2、博士研究生： 庄海峰 韩洪军教授 导 师： 申 学请学位： 工学博士 市政工程 科： 所 在 单 位： 市政环境工程学院 答 辩 日 期： 2015年7 月 授予学位单位： 哈尔滨工业大学 Dissertation for the Doctoral Degree in Engineering RESEARCH ON EFFICIENCY OF ADVANCED TREATMENT OF COAL GASIFICATION WASTEWATER BY CATALYTIC OZONATION INTEGRATED WITH BIOLOGICAL PROCESS Candidate： Zhuang

3、Haifeng Prof. Han Hongjun Supervisor： Academic Degree Applied for： Doctor of Engineering Municipal Engineering Speciality： Affiliation： Date of Defence： School of Municipal and Environmental Engineering July, 2015 Degree-Conferring-Institution： Harbin Institute of Technology 摘 要 近些年我国煤制气产业快速发展，在清洁和可

4、再生能源领域具有重要作用。然而，煤制气过程产生大量的废水无法通过常规的处理工艺获得理想的出水水质，二级生化工艺处理出水仍含有大量有毒和难降解物质，具有比原水更低的可生化性，该类废水的处理难题严重制约我国煤化工产业的健康发展。因此，亟需研发可以缓解有毒和难降解物质对微生物的抑制，实现污染物的大幅削减，促进水资源重复利用的经济高效的新型深度处理工艺。本课题系统和深入的研究了自制的成本低廉和性能高效稳定的催化剂催化臭氧化处理煤制气废水生化出水的效能和影响因素，探讨了该过程可能的催化机理和有机物的降解规律，同时考察了厌氧生物移动床（ANMBBR）耦合曝气生物滤池（BAF）复合生物短程脱氮技术的生物工艺

5、处理该废水的效能，并结合两种工艺的技术优势，建立了催化臭氧化-生物组合新型工艺，通过中试研究明确组合工艺处理该废水具有性能高效稳定，经济节约和可持续的技术优势，为煤制气废水深度处理提供了理论基础和技术支撑。 本研究以废水生物处理工艺产生的剩余污泥为原料制备污泥基活性炭(SBAC)，将其负载过渡金属氧化物作为臭氧催化剂。考察了制备工艺对催化剂活性的影响，结果表明金属种类和焙烧温度对催化剂活性影响显著，而浸渍和焙烧时间影响不显著。分析了研制的催化剂MnOx/SBAC和FeOx/SBAC的表征特点，两种催化剂均具有较高的比表面积，负载的金属氧化物以多种价态形式均匀分布在载体表面和孔隙内部，促进SBA

6、C表面碱性基团增加，进而提高了催化剂表面pHpzc值。同时，分析催化剂浸出液重金属特性，主要重金属离子浓度均低于国家规定的允许排放标准。通过十次连续催化试验考察其稳定性，该催化过程COD平均去除率仅降低5.4 %，催化剂金属离子溶出极少，不会产生二次污染。 考察了制备的催化剂催化臭氧化处理煤制气废水生化出水的效能和影响因素，最佳反应条件的实现不需对废水进行预处理，催化剂具有良好的应用性。催化剂的使用显著提高了臭氧氧化污染物的效能，处理后出水COD，总酚和TOC均达到了国家城镇污水处理厂污染物排放一级标准的A标准（GB18918-2002）。而且，催化臭氧化过程大幅提高了废水的可生物降解性并显著

7、降低了水质急性毒性，通过GC-MS技术明确该过程废水中主要有毒和难降解物质基本被去除，残留的是少量的氮杂环类和长链烷烃类。同时，分析了废水中典型的氮杂环类物质在该催化过程的去除性能和动力学规律，该类物质难以彻底臭氧氧化是导致处理后出水总氮去除不理想的重要原因。通过催化过程中添加羟基自由基捕获剂，抑制催化剂活性表达，探讨该催化过程可能机理是属于羟基自由基间接氧化为主导，多种 - I - 氧化反应协同作用。 考察了生物工艺ANMBBR-BAF去除煤制气废水生化出水污染物的效能和影响因素。确定最佳运行参数是水力停留时间12小时，回流比200 %，在此条件下，该生物工艺对废水中COD，氨氮，总酚和总氮

8、具有高效的去除效能。而且，该生物工艺具有较高的有毒负荷，显著优于传统的A2O脱氮工艺。基于催化臭氧化显著改善废水可生化性和ANMBBR-BAF工艺高效脱氮的技术优势，建立了催化臭氧化-生物组合新型工艺，同时实现了废水中污染物稳定高效的去除和运行成本的降低，最佳的运行时间为6小时，组合工艺对废水COD，TOC，氨氮，总氮和总酚的去除率分别为，和98.3 %，相对应的出水浓度分别为，和5.0 mg/L（BOD5），均达到了城镇污水处理厂污染物排放最高标准，该水质满足后续膜工艺的进水要求。通过GC-MS技术明确该组合工艺在短时间内高效去除废水中有毒和难降解有机物，特别是氮杂环类物质。 通过中试试验明

9、确组合工艺对煤制气废水生化出水的污染物具有高效稳定的处理效能，出水水质符合城镇污水处理厂污染物排放一级标准的A标准，满足后续膜工艺的进水要求，有利于煤制气废水“零排放”目标的实现。同时，催化剂对废水处理新增费用仅为平均元/t，与单独臭氧氧化废水获得同样的出水水质时，催化臭氧化节省了元/t；当获得更优质的水质时，催化臭氧化节省了91.7 %的费用。因此，催化臭氧化-生物组合工艺深度处理煤制气废水是经济节约，高效稳定和可持续的废水新型处理技术，具有重要的工程应用价值。 关键词：煤制气废水；催化臭氧化；催化剂；生物工艺；短程硝化反硝化 - II - Abstract The coal gasific

10、ation industry in China has been rapidly developed and played an important role in new clean and renewable energy market in recent years. However, the arbitrary discharge of coal gasi?cation wastewater (CGW) would cause a serious environmental problem, due to the presence of complicated and consider

11、able amounts of toxic and refractory compounds. Although conventional treatment of CGW quite effective, these processes are still not enough to meet the strict requirements of the National Discharge Standard of China. The biologically pretreated CGW still contains a large number of toxic and refract

12、ory compounds as well as their derivatives, with lower biodegradability than the raw wastewater. The wastewater control task has become a bottleneck for the quick development of coal gasi?cation industry in China. Thus, it is very important to find an efficient and cost-effective process for advance

13、d treatment of biologically pretreated CGW, which could enhance biodegradation and remove toxic inhibitory of raw wastewater, further improve effluent quality to meet the requirements of environmental protection and wastewater reuse. In the present work, advanced treatment of CGW was investigated an

14、d analyzed employing heterogeneous catalytic ozonation integrated with anoxic moving bed biofilm reactor (ANMBBR) and biological aerated filter (BAF) process and the economical cost and application prospect of the integrated processes were evaluated. Sewage sludge of biological wastewater treatment

15、plant was converted into sewage sludge based activated carbon (SBAC), which supported manganese and ferric oxides as catalysts to improve the performance of ozonation of real biologically pretreated CGW. Results demonstrate that the effects of metal type and roast temperature on catalytic activity w

16、ere significant. Catalysts exhibit typical mesoporous characteristics with high specific surface area and the high dispersion of transition metal oxides on the SBAC with the multivalence oxidation states increased the number of alkaline group, further increased pHpzc value of catalysts which was ben

17、e?cial to catalytic activity expression. In addition, heavy metals of leaching solution with prepared catalysts were investigated that the main heavy metal concentrations were lower than national requirements. Meanwhile, as compared to that achieved by the fresh catalysts, no remarkable change was o

18、bserved on the catalytic activity of the prepared catalysts after the tenth successive run, and the COD removal efficiency was only decreased by average 5.4 %, and leaching of Mn and Fe irons were very few, without second pollution for environment. Effects of important operating parameters on the pe

19、rformance of heterogeneous catalytic ozonation of biologically pretreated CGW were investigated. The addition of - III - the prepared catalysts signi?cantly improved the pollutants removal performance of ozonation of raw wastewater without substantial pre-adjustment quality. The treated wastewater w

20、ere more biodegradable and less toxic than that in ozone alone, and the effluent COD, total phenols(TPh) and TOC concentrations all met class-I criteria of the Integrated Wastewater Discharge Standard (GB18918-2002, China). Meanwhile, the raw and treated wastewaters were analyzed by the GC-MS, the r

21、esults indicated the catalytic ozonation with the prepared catalysts exhibited higher oxidative activity even completely mineralized toxic and refractory compounds and the residuals were nitrogen heterocyclic compounds (NHCs) and long-chain hydrocarbons compunds. In addition, the removal performance

22、 of typical NHCs of raw wastewater was analyzed in catalytic ozonation process. The results showed NHCs were difficult to mineralize by ozone oxidation which caused unsatisfied TN concentration in treated wastewater. Meanwhile, the effects of radical scavengers on TOC removal in ozonation without an

23、d with catalysts were performed. The results indicated that the main reaction pathways of catalytic ozonation involved the participation of the highly reactive hydroxyl radicals and the possible catalytic pathway was proposed. A novel system integrating ANMBBR and BAF with short-cut nitrification an

24、d denitrification process was investigated for treatment of biologically pretreated CGW. The results shows the system had efficient capacity of degradation of pollutants especially nitrogen compound removal. The best performance was obtained at hydraulic residence times of 12 h and nitrite recycling

25、 ratios of 200 %, the effluent COD, NH4+-N, TPh and TN concentrations all met class-I criteria of the Integrated Wastewater Discharge Standard. Meanwhile, compared with traditional A2/O process, the system had higher removal performance of NH4+-N and TN, especially the high toxic loading. Based on a

26、ctivated sludge intolerable limit of toxicity and enhancement of degree of wastewater biodegradability as evaluation criterias, operating parameters of the heterogeneous catalytic ozonation integrated with ANMBBR-BAF process were optimized with maximum biological process. The best performance of the

27、 integrated processes were obtained at hydraulic residence times of 6 h, the average removal efficiencies of COD, TOC, NH4+-N, TN and TPh were 73.1, 69.2, 93.3, 76.2 and 98.3 %, the corresponding effluent concentrations were 40.3, 15.4, 2.0, 13.1, 0.5 and 5.0 mg/L(BOD5), respectively, all allowing t

28、he discharge top limits to be met. Moreover, the integrated processes showed efficient degradation capacity of toxic and refractory compounds by GC-MS analysis. Pilot-scale study was also carried out to examine the application performance of the integrated processes as advanced treatment of CGW. The

29、 results show that the integrated processes had ef?cient and stable capacity of pollutants removal and the - IV - effluent quality all met the need of efficient reverse osmosis process which was beneficial to achieving “zero liquid discharge”. Moreover, the cost effect of the integrated processes on

30、 the wastewater treatment was evaluated. The new cost with application of catalysts was approximately 0.055 Yuan RMB per ton of wastewater. Compared to single ozone oxidation with the same effluent quality, catalytic ozonation process saved about 0.67 Yuan RMB per ton, while better effluent quality,

31、 catalytic ozonation process saved 91.7 % cost. Therefore, the integrated processes with efficient, stable, economical and sustainable advantages were suitable for advanced treatment of real CGW. Keywords: Coal gasification wastewater, Catalytic ozonation, Catalyst, Biological process, Short-cut nit

32、rification and denitrification - V - 目 录 摘 要 . I ABSTRACT . III 第1章 绪 论 . 1 1.1 课题研究的背景 . 1 1.1.1 煤制气产业的重要性和制约因素 . 1 1.1.2 煤制气废水的处理现状 . 2 1.1.2.1 分离技术 . 2 1.1.2.2 生物技术 . 3 1.1.2.3 高级氧化技术 . 5 1.1.3 煤制气废水处理存在问题 . 8 1.2 生物脱氮工艺 . 8 1.2.1 基于亚硝酸盐的脱氮 . 8 1.2.2 厌氧氨氧化生物脱氮工艺 . 10 1.3 非均相催化臭氧氧化技术研究进展 . 11 1.3.

33、1 金属氧化物作为催化剂 . 11 1.3.2 负载型催化剂 . 12 1.3.3 天然矿石和固体废弃物制备催化剂 . 14 1.3.4 非均相催化臭氧氧化的机理 . 14 1.3.5 非均相催化臭氧氧化技术存在的问题 . 16 1.4 课题研究的目的和意义 . 16课题的来源 . 16课题的研究目的和意义 . 16 1.5 课题研究的内容 . 17 第2章 试验材料与方法 . 20 2.1 试验材料和仪器 . 20试验材料 . 20试验仪器 . 23 2.2 试验方法 . 24 2.2.1 催化剂的制备 . 24臭氧和催化臭氧氧化试验 . 25 2.2.3 生物反应器的启动和运行 . 28

34、- VI - 2.2.4 催化臭氧化-生物组合工艺 . 31 2.3 分析方法 . 31 第3章 非均相催化臭氧催化剂的制备及其特性表征 . 34 3.1 引言 . 34污泥基活性炭的制备 . 34 3.3 催化剂的活性分析 . 35 3.4 制备的催化剂特性表征 . 38 3.4.1 催化剂形貌分析 . 38催化剂元素组成和晶体结构以及官能团特点 . 40 3.4.3 催化剂吸附性能 . 42催化剂浸出液重金属特性 . 43催化剂稳定性 . 44 3.5 本章小结 . 46 第4章 非均相催化臭氧化深度处理煤制气废水效能的研究 . 47 4.1 引言 . 47催化臭氧化处理煤制气废水生化出水的影响因素 . 48臭氧投加量的影响 . 48催化剂投加量的影响 . 49 4.2.3 反应温度的影响 . 51 4.2.4 废水pH值的影响 . 51催化臭氧化对废水污染物的去除性能 . 53 4.4 催化臭氧氧化与Fenton氧化工艺的比较 . 56 4.5 催化剂催化臭氧氧化煤制气废水生化出水的机理探讨 . 59可生物降解性和急性毒性的分析 . 62 4.7 催化臭氧化对废水主要有毒和难降解物质的去除 . 64 4.7.1 催化臭氧化对废水主要有毒和难降解物质去除规律探讨 . 6