中文摘聚羟基烷酸酯(PHA)类羟基脂肪酸聚合物外界环境较恶劣时局部微生物体碳源形式贮存PHAPHA具生物相容性生物降解性时根单体组分具石化塑料相类似种物理性质代现行难降解塑料缓解环境固体废弃物污染然目前PHA商业化生产采纯菌发酵方式钱较高阻碍PHA规模应采活性污泥混合菌群生产PHA采廉价机废物底物降低PHA生产钱两段式PHA生产工艺包括机废物厌氧酸化PHA生产两步者时间分污泥适应阶段PHA积累阶段适应阶段采均衡营养例PHA积累阶段限制进水中营养元素研究发现PHA积累阶段步减少进水中80(相均衡例)氨氮逐步减少更效促进PHA积累周期底物消耗完毕条件底物乙酸钠污泥水解液该阶段反响器厌氧氧运行氧运行结果没区研究发现适应期污泥龄较长时保证反响器长时间稳定运行污泥龄较短时易引发污泥膨胀污泥龄低5天引发污泥膨胀会污泥产PHA力降污泥水解液底物时中VFAs快速吸收PHA积累中氨氮水关系三段式PHA生产工艺包括机废物厌氧酸化菌群富集PHA积累中菌群富集重步研究乙酸钠底物考察SBR富集产PHA菌群时发现反响器易发生污泥膨胀污泥龄1天底物负荷较高(66 g CODLd)时反响器膨胀非常严重量泡沫产生污泥快丧失产PHA力污泥龄10天负荷较低(27 g CODLd)条件膨胀污泥具较高PHA合成力氧SBR运行102天时污泥积累PHA含量达53PHA均积累速率019 mg CODmg XhPHA产率076 mg CODmg CODSBR步运行厌氧氧SBR运行55天左右突然崩溃污泥浓度甚缺乏500 mgL蔗糖模拟糖蜜废水厌氧酸化PHA合成时产酸反响器启动运行1月逐渐稳定乙醇型发酵时出水中空纤维膜滤SBR富集产PHA混合菌群PHA积累实现生物制氢PHA合成系统耦合SBR运行负荷4245 g CODLd污泥龄10天启动运行1月污泥浓度3300 mgL增8000 mgL底物充盈时溶解氧控制30 mgL左右然30天时SBR然发生污泥膨胀污泥浓度导致发现膨胀污泥底物吸收PHA合成生长方面非膨胀污泥快1倍左右实验SBR运行25天时系统消耗1 kg COD蔗糖约生产16 L氢气01 kg CODPHA中单体HV质量约占24左右
英文摘Polyhydroxyalkanoates (PHAs) are a class of polymers which can be accumulated as internal carbon sources by part microorganisms under adverse circumstances PHAs are biocompatible and biodegradable and can also possess the similar properties with the petro made plastics which enables them to substitute the current plastics to reduce solid wastes However PHAs in market are all commercially produced by pure cultures which bring about high costs and hampered their largescale application PHA production by mixed microbial cultures can be completed in open reactors and future more more cheap organic wastes can be used This would make cost reduction possibleTwostage PHA production process includes acidogenic fermentation of organic wastes and PHA production and the latter is composed by sludge acclimation and PHA accumulation In sludge acclimation nutrients are balanced while in PHA accumulation nutrients are unbalanced In this study results showed that direct limitation of ammonia by 80 (compared with balance level) in influent could better stimulate PHA accumulation than gradual limitation When there was no substrate left in every cycle little difference was observed in PHA accumulation between anaerobicaerobic and aerobic operation with substrate as acetate or sludge alkaline fermentation liquids It can also be drawn that long sludge retention time would guarantee longterm stability of the reactor while low sludge retention time would bring about sludge bulking Especially when sludge retention time was lower than 5 days the PHA storage capacity would be damaged VFAs could be uptaken rapidly and the PHA accumulation depended highly on the level of ammonia when the substrate was sludge alkaline fermentation liquidsThreestage PHA production process includes acidogenic fermentation of organic wastes culture selection and PHA accumulation and stage of culture selection is the most important It was observed that bulking sludge was easily established when selecting cultures in SBR with actate as substrate Under SRT of 1d and high organic loading rate (66 g CODLd) the bulking was more severe with a great deal of foam and poor PHA storage ability While under SRT of 10 d and low organic loading rate (27 g CODLd) bulking sludge possessed high PHA storage capacity After 102 days’operation sludge from SBR could accumulate PHA to 53 of TSS under ammonia starvation with average storage rate of 019 mg CODmg Xh and yield of 076 mg CODmg COD However another SBR operated in parallel with anaerobicaecobic pattern suddenly failed after 55 days’operationWhen using cane sugar to simulate molassess as the substrate after anaerobic fermented for PHA production the CSTR gradually stablized towards ethonaltype fermantation one month after startup The effluent was clarified with hollow fiber membrane and then was used for culture selection and PHA accumulation thus coupling biohydrogen production with PHA production system was achieved The TSS in SBR rised up to more than 8000 mgL from 3300 mgL with organic loading rate of 4245 g CODLd and SRT of 10 d Although DO was maintained above 3 mgL in feast phase sludge bulking still happened after 30 days’operation This may be caused by high sludge concentration Bulking sludge exhibited higher rates in substrate uptake PHA storage and biomass proliferation than wellsettling sludge about 2 times than the latter When SBR run 25 days after inoculation the whole system could produce 16 L H2 and 01 kg COD PHA using 1 kg COD cane sugar The HV weight proportion of PHA was 24 approximately
关键词聚羟基烷酸脂 混合菌群 污泥膨胀 生物制氢 PHA合成
英文关键词polyhydroxyalkanoates mixed microbial culture sludge bulking biohydrogen production PHA synthesis
目录两段式三段式工艺制取聚羟基烷酸酯试验研究
摘
46
Abstract
67
第1章 绪
1131
11 课题背景
1112
111 课题源
11
112 课题研究目意义
1112
12 PHA 概述
1219
121 PHA 结构性质
1214
122 细胞储存PHA 微生物学意义
1415
123 微生物合成PHA 代谢机制
1518
124 PHA 提取回收
1819
13 混合菌群合成PHA 国外研究现状
1929
131 底物选择
1920
132 工艺流程
2022
133 工艺运行策略
2225
134 影响素
2529
14 研究容
2931
第2章 实验材料方法
3136
21 实验装置运行工况
3133
211 实验装置
3132
212 设备仪器
3233
22 检测方法
3336
221 PHA 检测
33
222 乙醇VFAs 检测
3334
223 气体成分检测
34
224 常规指标测定分析方法
3436
第3章 两段式PHA 制取工艺优化
3649
31 氨氮限制方式PHA 积累影响
3639
311 实验工艺控制
3637
312 污泥性状变迁
3738
313 限制进水氨氮PHA 循环积累
3839
32 PHA 积累期厌氧氧氧运行方式
3941
321 实验工艺控制
3940
322 底物消耗PHA 积累
4041
33 短污泥龄短周期污泥适应期
4145
331 实验工艺控制
42
332 污泥性状变迁
4243
333 底物消耗PHA 积累
4345
34 污泥水解液两段式工艺
4548
341 实验工艺控制
4546
342 底物污泥水解液时PHA 积累情况
4648
35 章结
4849
第4章 乙酸钠底物富集产PHA 混合菌群
4963
41 实验工艺控制
4950
42 第阶段SBR 运行状况
5051
43 膨胀污泥合成PHA
5158
431 富集反响器污泥膨胀
52
432 厌氧氧运行SBR 表现
5253
433 氧运行SBR 表现
5354
434 两SBR 中PHB 含量变化
5455
435 两SBR 富集污泥积累PHB
5557
436 PHB 积累程中膨胀污泥性状变化
5758
44 污泥增殖PHA 积累循环模式
5861
441 实验工艺控制
5859
442 污泥增殖
5960
443 PHB 积累
6061
45 章结
6163
第5章 三段式PHA 制取工艺初步探索
6376
51 实验工艺控制
6365
511 CSTR 运行工况
6364
512 SBR 运行工况
64
513 PHA 积累实验
6465
52 CSTR 启动稳定运行
6566
53 SBR 启动运行监测
6669
531 接种污泥浓度SVI 变化
6667
532 SBR 周期参数变化
6768
533 未膨胀污泥膨胀污泥合成PHA
6869
54 PHA 积累实验
6973
541 进水底物浓度PHA 积累影响
6971
542 进水底物pH PHA 合成影响
7172
543 SBR 运行程中剩余污泥合成PHA
7273
55 生物制氢PHA 生产工艺耦合
7375
56 章结
7576
结
7677
建议
7778
参考文献
7886
致谢
86
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