79 resultados para Aerobic sludge
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评价原状土通气培养法在反映黄土高原土壤供氮能力方面的效果。【方法】以采自于黄土高原差异较大的11个农田耕层土壤为供试土样,以包括和不包括土壤起始NO3--N原状土盆栽黑麦草累积吸氮量为参比,进行室内原状土通气培养法测定土壤供氮能力的研究。【结果】以包括土壤起始NO3--N盆栽试验植物吸氮量为参比,通气培养前CaCl2所淋洗起始NO3--N和起始矿质氮与5期黑麦草地上部氮素累积量密切相关,相关系数分别为0.856和0.862,达1%显著水平;与此相反,通气培养30周所矿化氮素、土壤起始矿质氮+通气培养30周矿化氮素、氮素矿化势(N0)及N0+起始矿质氮与5期黑麦草地上部氮素累积量间无显著相关关系,相关系数分别仅为0.410、0.553、0.492和0.419。以不包括土壤起始NO3--N盆栽试验植物吸氮量为参比,通气培养前CaCl2淋洗起始NO3--N和起始矿质氮与五期黑麦草地上部氮素累积量间的相关性尽管有所降低,但相关性仍达5%显著水平,相关系数分别为0.613和0.607;而通气培养30周矿化氮素、土壤起始矿质氮+通气培养30周矿化氮素、N0及N0+起始矿质氮与五期黑麦草地上部吸氮量的相关系数却明显...
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采用间隙淋洗长期通气培养法,通过对黄土高原物理化学性质差异较大的10种农田土样起始矿质氮、起始提取态总氮、起始可溶性有机氮,以及培养期间淋洗矿质氮、淋洗总氮、可溶性有机氮含量及其与作物吸氮量关系的研究,分析并评价黄土高原主要农田土壤氮素矿化能力以及包括和不包括培养淋洗可溶性有机氮对土壤供氮能力的影响。结果表明,供试土样起始可溶性有机氮平均为N 23.9 mg/kg,是起始提取态总氮的28.8%,土壤全氮的2.4%。在通气培养淋洗总氮中,可溶性有机氮所占比例不高,经过217 d通气培养,淋洗出的可溶性有机氮平均为N 28.8mg/kg,占淋洗总氮量的19.8%。相关分析表明,淋洗可溶性有机氮量与第l季作物吸氮量相关不显著,但与连续2季作物总吸氮量显著相关。淋洗矿质氮、淋洗总氮与两季作物总吸氮量的相关系数明显高于与第一季作物吸氮量的相关系数;与第一季作物吸氮量达显著相关水平,与连续两季作物吸氮量达极显著相关水平。总体上看,可溶性有机氮和土壤全氮、土壤微生物氮不能作为反映短期可矿化氮的指标;间隙淋洗通气培养淋洗液中淋洗矿质氮、淋洗总氮是评价可矿化氮的较好指标,不仅适宜于第一季作物,而且也适用于对连续两季作物土壤供氮...
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含油污泥已作为危险废物列入《国家危险废物名录》(HW08),其处理问题已成为环保领域研究的热点。热洗技术是含油污泥处理的主流技术,而清洗药剂作为该技术的核心,直接影响含油污泥的处理指标与效率。目前,适合热洗处理的化学药剂很少,迫切需要开发专用药剂技术。针对含油污泥清洗效率的难题,本文合成了一种新型高效的含油污泥清洗剂。 本文以甲基丙烯酸(MAA)、丙烯酸丁酯(BA)和苯乙烯(St)为混合单体,偶氮二异丁腈(AIBN)为引发剂,通过溶液聚合的方法探索合成了一种高分子聚合物(命名为MBS)。分析讨论了MBS关键单体的选择、合成设计及方法,检测了MBS有关物理化学性能,考察了单体、引发剂用量及清洗条件对MBS脱油性能的影响,探讨了MBS对含油污泥中原油不同组分的去除效率,并用红外光谱证实了MBS结构的官能团。 MBS在单体质量比为MAA:BA:St=21:62:17,引发剂AIBN为单体总量的1.2%时,含油污泥脱油率可达84%以上。MBS对于含油污泥中芳烃去除率最高,为93.0%;其次是烷烃,去除率为87.4%;沥青质、胶质最低,去除率为71.8%,具有良好的处理效果。 本文还针对目前国内尚无评价含油污泥清洗剂的标准方法,对清洗剂性能评价进行了初探,采用统一标准的模拟含油污泥进行清洗剂性能评价,并提出了制备方法,同时验证了在此基础上所建立的性能评价方法。结果证明,模拟含油污泥能够真实体现清洗剂的脱油性能,所建立的评价方法可以作为一种通用规范的含油污泥清洗剂性能评价的基本方法。
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由于含油污水灌溉、原油储存运输和石油冶炼过程中导致的泄漏事故等原因,石油类物质已经成为环境中的主要污染物之一。石油烃污染物对土壤微生物遗传多样性和群落结构的影响在国外已有一些报道,但有关于石油烃污染对稻田土壤微生物生态系统的影响一直以来一直没有一个全面和系统的认识。本论文首次采用传统微生物培养方法、常规生化分析方法与PC树DGGE等现代分子生态学研究方法相结合的手段系统评价了长期石油污水灌溉对中国最大的石油类污水灌区-沈抚灌区的稻田土壤微生物种群数量、细菌群落组成、多样性及代谢活性的影响。结果表明,总石油烃(Total Petloleum hydrocarbon/TPH)在灌区干渠和支渠中的积累和分布趋势大体上是上游地区较严重,下游地区较轻,并且与土壤中有机质含量呈显著正相关。在目前的污染程度下,石油污水能够刺激土壤好氧异养细菌(Aerobic heterotrophic bacteria/AHB)和真菌的生长,其数量与TPH含量呈显著正相关。细菌基因多样性与TPH含量呈显著负相关,细菌群落中的优势菌群为变形细菌β-亚群和γ-亚群的菌种。土壤脱氢酶、过氧化氢酶、多酚氧化酶活性和土壤底物诱导呼吸(substrate-induced respiration/SIR)与土壤中TPH含量呈显著正相关,而土壤脉酶活性则与之呈显著负相关。实验室110天不同浓度石油烃胁迫模拟试验结果表明,当石油烃胁迫浓度低于1000mgk扩时可以被定义为轻度污染,土壤中AHB大量增殖,细菌多样性和群落结构可在处理第30天和第50天得到恢复;当石油烃胁迫浓度为5000mg·kg~(-1)-10000mg·kg~(-1)时可以被定义为中度污染,AHB数量显著增加,放线菌和真菌数量显著降低,土壤细菌多样性在培养前巧天显著降低,至培养结束时有逐渐恢复的趋势,细菌群落结构发生明显改变,土壤脱氢酶、多酚氧化酶、脉酶的活性及土壤SIR受到一定程度的抑制,但能够显著刺激土壤过氧化氢酶活性的提高。当石油烃胁迫浓度为10000mg·kg~(-1)-50000mg·kg~(-1)时可以被定义为重度污染,对AHB生长的刺激作用更为显著,土壤细菌多样性在培养前15天显著降低并不可恢复,群落组成与对照差异很大,所有土壤酶和SIR均受到严重抑制。从沈抚灌区上游地区旱田土壤、灌渠底泥和实验室高浓度石油烃胁迫土壤中筛选出了4株TPH生物降解率在60%以上的高效石油烃降解菌并鉴定其归属,这些菌株均能够利用正构烷烃、单环和多环芳烃及环烷烃。
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花椒(Zanthoxylum bungeanum)是川西干旱河谷地区重要的经济作物,化感作用是花椒连作障碍的重要原因之一。花椒凋落物分解是影响花椒林地土壤肥力及花椒产量的重要因素,因此系统研究花椒化感作用是否对花椒凋落物的分解产生影响可以为解决花椒连作障碍导致的产量下降等问题提供科学的理论依据。本文通过室内模拟实验研究了花椒凋落物的四个分解动态以及分解后凋落物浸提液对花椒林地土壤性质的影响;通过野外盆栽实验研究了花椒凋落物浸提液对花椒幼苗的生长、花椒凋落物的质量及土壤性质的影响。最终从生理生化角度揭示了花椒的化感作用对凋落物分解的影响机理,为深入解决花椒连作障碍问题、对花椒凋落物采取有效的人工措施提供了科学的理论依据。主要的研究结果如下: 1. 室内分解实验证明,花椒凋落物在分解的60 d 内分解速率呈现由大到小的变化趋势,并且凋落物分解呈现明显的毒性动态。凋落物在分解的10 d、30 d 时,分解速率较大,30 d 以后分解速率显著降低。凋落物分解的10 d 左右酚酸释放量最大,此时凋落物的毒性最大,凋落物分解到10 d 以后,酚酸释放量逐渐减少,凋落物的毒性也逐渐减小。 2. 四个分解动态的花椒凋落物浸提液对土壤化学性质产生了显著的影响。花椒凋落物在分解的60 d 内,其浸提液使土壤pH值均显著的增加。分解0 d 的凋落物浸提液显著的降低了土壤铵态氮的含量,抑制了纤维素分解菌的生长;分解60 d 的凋落物浸提液显著的降低了土壤酚酸含量,增加了土壤有效磷的含量;分解30 d 和60 d 的凋落物浸提液均显著的促进了好气性纤维素分解菌的生长。这说明花椒凋落物在分解过程中呈现出明显的毒性动态:凋落物分解的初期毒性作用较大,随着分解的继续进行特别是在分解的30 d 以后,其毒性作用慢慢降低。 3. 花椒凋落物浸提液对花椒幼苗表现出明显的化感作用。不同浓度的浸提液对花椒幼苗地上及地下生物量、叶面积均产生了显著的抑制作用,并且随着浸提液浓度的升高抑制作用加强。凋落物浸提液对叶片厚度的影响较小,只有Y1对叶片厚度的生长抑制作用显著。 4. 花椒的化感作用改变了凋落物的质量,并对凋落物分解产生了显著的影响。对花椒幼苗用不同浓度的凋落物浸提液进行处理,Y1使凋落物有机碳含量、木质素含量、C/N、木质素/氮显著降低,纤维素含量显著升高;Y3使凋落物有机碳含量、木质素含量、C/N、木质素/氮显著升高。花椒凋落物质量的改变显著的影响了凋落物的分解,凋落物的分解速率大小依次为:Y1(10.15 a-1)> Y2(8.71 a-1)> CK(6.41 a-1)> Y3(5.08 a-1)。 5. 花椒的化感作用改变了土壤性质,并对凋落物分解产生了显著的影响。对花椒幼苗用不同浓度的凋落物浸提液处理的同时,也改变了土壤性质。不同浓度的凋落物浸提液显著的升高了土壤pH值、有机碳含量。各种浓度的凋落物浸提液对土壤多酚氧化酶的活性均起到了显著的促进作用。凋落物浸提液Y1对土壤纤维素分解酶的活性、细菌和真菌的生长也具有显著的促进作用。土壤性质的改变显著的影响了凋落物的分解,凋落物的分解速率大小依次为:Y1(10.30 a-1)>Y2(9.60 a-1)>CK(6.41 a-1)>Y3(6.29 a-1)。 6. 不论是凋落物质量发生改变还是土壤性质发生改变,在凋落物分解的整个过程中,C元素始终处于单调净释放的状态,并且C释放量与分解速率成显著的正相关,即凋落物分解越快,凋落物C释放量越大。凋落物分解过程中,均出现了酚酸大量释放的情况,并与凋落物分解速率成显著正相关。凋落物分解后的木质素含量、木质素/氮均增加,并且随着浸提液浓度的升高,凋落物木质素含量、木质素/氮升高。 Zanthoxylum bungeanum is an important economic crop in dry valley of the Minjiang river (Sichuan, Southwest China), but allelopathy is one of the important reasons for its continuous cropping. Zanthoxylum bungeanum litter decomposition affects Zanthoxylum bungeanum soil fertility and its output. So systemically investigate if allelopathy affects litter decomposition could provide the scientific methods to solve the problem of output fall caused by the continuous cropping. In this paper, the releasing dynamics of phenolic acid during Zanthoxylum bungeanum litter decomposition (0, 10, 30 and 60 days) and the effects of its aqueous extract on soil chemical properties were investigated via the laboratory study. Effects of Zanthoxylum bungeanum litter aqueous extract on the growth of young Zanthoxylum bungeanum seedlings, litter qualities and the soil qualities were investigated via the field study. Finally, we open out the action manner of Zanthoxylum bungeanum allelopathic effect on the litter decomposition, and provide the theoretical basis to solve the Zanthoxylum bungeanum continuous cropping. The main results showed that: 1. The laboratory litter decomposition experiment showed a trend of decomposition rate from large to small and an occurrence of phytotoxicity with clear dynamic patterns during Zanthoxylum bungeanum litter decomposition. The litter decomposition rate was larger at the tenth and 30th day during 60-day litter decomposition and gradually decreased after 30 days of litter decompostion. The releasing quantity of the litter phenolic acid was the highest at the tenth day, and here, the litter toxicity was the biggest. The releasing quantity of the litter phenolic acid gradually decreased after 10 days of litter decomposition, so the phytotoxicity of litter was gradually decreased with the litter decomposition. 2. The Zanthoxylum bungeanum litter aqueous extract after four decomposition stages had significantly effect on the soil chemical qualities. The pH value in soil was significantly increased in litter aqueous extract of four decomposition stages. The NH+4-N concentration was significantly decreased in soil amended with litter aqueous extract of 10-day decomposition which inhibited the growth of Aerobic cellulose-decomposer. The growth of soil Aerobic cellulose-decomposer was promoted by the litter aqueous extract of 30-day decomposition. Available phosphorus concentration was significantly increased and phenolic acid content was significantly decreased in soil amended with litter aqueous extract of 60-day decomposition which promoted the growth of Aerobic cellulose-decomposer. The study results showed an occurrence of phytotoxicity with clear dynamic patterns during Zanthoxylum bungeanum litter decomposition. The phytotoxicity of litter was the largest at the initial stage, but the phytotoxicity gradually decreased with the litter decomposition, especially after 30 days of decomposition. 3. The field study indicated that the Zanthoxylum bungeanum litter aqueous extract had significant allelopathic effects on the growth of young seedlings.Different concentration aqueous extract had signinficant inhibiting effects on biomass and leaf area of young seedlings. The inhibiting effect on the biomass strengthened with the litter aqueous extract concentration augment. Litter aqueous extracts had less effect on the leaf thickness, and only Y1 had significant inhibiting effect on the leaf thickness. 4. The Zanthoxylum bungeanum allelopathy had significant effect on the litter qualities and the litter decomposition. Treating the young Zanthoxylum bungeanum seedlings with different concentration of litter aqueous extracts, the leaf litter organic C, lignin, C/N and lignin/N all decreased and the cellulose content increased under Y1 treatment. The leaf litter organic C, lignin, C/N and lignin/N all increased under Y3 treatment. So the litter decomposition was significant affectded by the litter qualities, and the litter decomposition rate was Y1(10.15 a-1)> Y2(8.71 a-1) > CK(6.41 a-1) > Y3(5.08 a-1). 5. The Zanthoxylum bungeanum allelopathy had significant effect on the soil qualities and the litter decomposition. Treating the young Zanthoxylum bungeanum seedlings with different concentration of litter aqueous extracts, also changed the soil qualities. Different concentration of litter aqueous extracts had significant effects on the soil pH and organic C content. Every concentration of litter aqueous extracts accelerated the soil Polyphenol Oxidase activity and Y1 accelerated the soil Cellulase activity, the number of soil bacteria and fungi. So the litter decomposition was significant affected by the soil qualities, and the litter decomposition rate was Y1(10.30 a-1) > Y2 (9.60 a-1) >CK(6.41 a-1)>Y3(6.29 a-1)。 6. Whether the litter or soil qualities changed, the litter C element at the state of release at all times during the litter decomposition, and the release quantity increased with the decomposition rate augment. Litter released plentiful total penolics content during decomposition, and the release quantity had the positive correlation with the litter decomposition rate. The litter lignin content and the lignin/N all increased with the litter aqueous extracts concentration augment after litter decomposition.
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本文对无介体双室微生物燃料电池的产电性能进行了初步研究,并根据不同运行阶段产电性能的优劣,对其中微生物的差异性进行了比较分析。全文分为两个部分: 第一部分:以乙酸钠为阳极原料构建双室微生物燃料电池(MFC),研究不同阴极受体、外接电阻、乙酸钠浓度和pH等因素对电池产电性能的影响,研究结果表明:在500mL的阴阳极反应体系中,选用乙酸钠作为阳极底物,质量浓度为6.46 g/L, pH 7.0,接入500Ω外电阻,阴极电子受体选择高锰酸钾的情况下,微生物燃料电池产电性能最好,最大电功率密度达到294.72 mW/m2,库伦效率能达到25.87%。在确定最适外接电阻阻值的同时对MFC内阻进行测定,阻值为871.87Ω。 第二部分:微生物燃料电池运行中,比较以厌氧污泥作为接种源的第一阶段和只接入附着有大量微生物电极的第二阶段的产电性能,得出第二阶段产电性能优于第一阶段,最大电功率密度达到353.57mW/m2,比第一阶段提高58.85 mW/m2;库伦效率为39.35%,增幅达52%左右;针对微生物燃料电池运行过程中,底物CH3COONa可能存在其它的代谢途径,本实验进行了第二阶段产电性能与CH3COONa消耗率关系以及阳极液面上方气体成分和含量的研究,发现第二阶段50h前CH3COONa的大量消耗主要用于微生物的生长,在整个运行过程中,阳极液面上方含有CH4和CO2;对气体测定的同时还发现,振荡能增强电功率密度的输出;通过对电极上和污泥中微生物差异性分析得出,δ-变形菌纲、β-变形菌纲和拟杆菌门的菌种更适应微生物燃料电池的运行环境,能在电极上大量富集,提高电池的产电性能,只接入附着有大量微生物的电极能有效降低热袍菌纲的菌种数量,降低了CH3COONa的无为消耗,有效提高了电池的库伦效率。 Electricity production in the mediator-less two-chambered microbial fuel cell(MFC) was researched. Based on the result in the different operation phase in the MFC, the microbial diversity was analysed. The paper involved two parts: Part 1: A two-chambered microbial fuel cell (MFC) was constructed with high-concentration sodium acetate as fuel in the anode. The influence of different electron acceptors in the cathode, external resistance value, pH value and concentration of sodium acetate on electricity generation in MFC was investigated. The result showed that the maximum power density of 294.72 mW/m2 and the coulombic efficiency of 25.87% was achieved at sodium acetate concentration of 6.46 g/L, pH 7.0, external resistance 500Ωin the anode and when using potassium permanganate as electron acceptor in the cathode. While decided the value of resistor, we found that shaking has effect on electricity production in the MFC. Part 2: Comparing the electricity production in different operation phases when using anaerobic sludge as inoculum in the first phase and microbes in the anodic electrode as inoculum in the second phase, the result showed that electricity production in the second phase was more than that in the first phase, the maximum power density of 353.57 mW/m2 and the coulombic efficiency of 39.35% was achieved, 58.85 mW/m2 and 52% more than that in the first phase, respectively. According to the fact that CH3COONa might be metabolized in other pathway in the running process in the MFC, we determining the relationship between electricity production and CH3COONa consumption, and the gas content in the anode, we found that CH3COONa was mainly used for microbe growth before 50h, and the anode contained CH4 and CO2. At the same time, we found that shaking could improve power density. The analysis on diversity of microbe in the anodic electrode and anaerobic sludge showed that δ-proteobacterium, β-proteobacterium and Bacteroidetes adapted themselves to the running environment of MFC. The anode could enrich them to improve the electricity production while reduced the quantity of Thermotogales, which were obligately anaerobic organotrophs with a fermentative metabolism, to increase the coulombic efficiency effectively.
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本文从四川绵竹酒厂、成都市龙泉长安垃圾填埋场以及四川大学荷花池底的厌氧污泥中先后分离得到63株厌氧产氢菌,其中H-8、H-61、HC-10等16株产氢细菌产氢能力较高,HC-10的产氢能力最高,最大产氢量和最大产氢速率分别达到2840 ml H2/L培养基和25.39 mmol H2/g drycell·h,对HC-10进行生理生化鉴定和分子生物学鉴定,判定其为clostridium sp.,对HC-10的产氢条件进行了研究,结果表明,该菌的最适生长温度为35 ℃,最适生长初始pH为7,以葡萄糖为最佳碳源,以蛋白胨为最佳氮源,不利用无机氮源,其产氢发酵液相产物以乙醇和乙酸为主,其发酵类型属于乙醇型发酵。此外,以酒糟废液作为底物,进行了菌株HC-10的生物强化试验,研究表明,投加了HC-10的强化系统其产氢量比对照高出40.32%。 同时为了获得厌氧产氢菌的高效突变株,分别以产氢菌H-8和H-61为原始菌株进行微波诱变处理,对微波诱变参数进行了优化,考察了突变株的遗传稳定性、产氢特性及耐酸性。菌株H-8经过微波诱变得到5株高产氢突变株HW7、HW33、HW181、HW184、HW195,经多次传代表明HW195是稳定的高产突变株。突变株HW195具有较好的耐酸性,在pH值为2.8时仍能生长。通过间歇发酵实验,其最大产氢量和最大产氢速率分别达到2460 mL/L培养基和27.97 mmol H2/g drycell·h,比原始菌分别提高了50.75%和41.7%。菌株H-61经过微波诱变后选育得到的突变株HW-18,其最大产氢量和最大产氢速率分别达到2190 mL/L培养基和25.86 mmol H2/g drycell·h,比原始菌分别提高了23.03%和31.00%。 为了对比各种诱变方式对产氢菌产氢能力的影响,以厌氧产氢菌H-61为原始菌株,先后经亚硝基胍(NTG)、紫外(UV)诱变,选育得到1株高产突变株HCM-23。在葡萄糖浓度为10 g/L的条件下,其产氢量为3024 mL/L培养基,比原始菌株提高了69.89%;其最大产氢速率为33.19 mmol H2/g drycell·h,比原始菌株提高了68.14%。经过多次传代实验,稳定性良好。其发酵末端产物以乙醇和乙酸为主,属于典型乙醇型发酵。其最适产氢初始pH为6.5,最适生长温度为36 ℃,以蔗糖为最佳碳源。与原始菌株相比,突变株HCM-23的产氢特性发生了改变,如生长延滞期延长,可利用无机氮源等。 From anaerobic activated sludge, 16 strains of hydrogen producing bacteria were newly isolated. One of them named as HC-10 had the highest hydrogen producing capability, under the batch fermentative hydrogen production condition, the maximal hydrogen yield and hydrogen production rate was 2840 mL/L culture and 25.39 mmol H2/g drycell·h. It was identified as clostridium sp.HC-10 by 16S rDNA sequence analysis. Various parameters for hydrogen production, including substrates, initial pH and temperature, have been studied. The optimum condition for hydrogen producing of strain HC-10 were achieved as: initial pH 7.0, temperature 35 ℃, glucose as the favorite substrate, Moreover, using distiller's solubles wastewater as substrate, HC-10 strain was added in the biohydrogen producing system to research the bioaugmentation effection. The results showed that the hydrogen production of bioaugmentation system was 40.32% higher than the noaugmentation system. An anaerobic, hydrogen producing strain H-8 was irradiated by microwave to optimize the microwave mutagenesis condition, and to test the heredity, hydrogen-producing potential and aciduric of the mutants. An aciduric mutant named as HW195 with steady hydrogen-producing capability was obtained, which can grow at pH 2.8. Its capability of hydrogen production was tested in the batch culture experiments. The maximum hydrogen yield and hydrogen production rate was 2460 mL/L culture and 29.97 mmol H2/g drycell·h, which was 50.7% and 41.7% higher than those of the initial strain, respectively. When used the strain H-61 as original strain, a mutant named as HW18 was obtained. The maximum hydrogen yield and hydrogen production rate was 2190 mL/L culture and 25.86 mmol H2/g drycell·h, which was 23.03% and 31.00% higher than those of the initial strain, respectively. The results demonstrated that microwave mutagenesis could be used in the field of hydrogen producing microorganism. The hydrogen producing strain H-61 was used as an original strain which was induced by NTG and UV for increasing and the hydrogen production capability. One of the highest efficient H2-producing mutants was named as HCM-23 with its stable hydrogen production capability. which was tested in the batch culture experiments. With the condition of 10 g/L glucose, its cumulative hydrogen yield and hydrogen production rate was 3024 mL/L culture and 33.19 mmol H2/g drycell·h, 69.89%and 68.14% higher than that of the original strain, respectively. The terminal liquid product compositions showed that the mutant HCM-23 fermentation was ethanol type, while the original strain H-61 fermentation was butyric acid type. Varieties of parameters of hydrogen production fermentation were studied, including time, carbon source, nitrogen source, glucose concentration, glucose utilization, initial pH and incubation temperature had been studied, indicated the optimum condition of hydrogen production for the mutant HCM-23 as initial pH6.5, temperature 36 ℃, and the favorite substrate was sucrose. The hydrogen production characters of the mutant and the original strain were different, such as, the growth lag phase and the utilization of inorganic nitrogen source, etc. This work shows a good application potential of NTG-UV combined mutation in the biohydrogen production. And the hydrogen production mechanism and metabolic pathway should be explored furthermore.
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猪场废水COD浓度高、氨氮浓度高、悬浮物浓度高,已成为农村面源污染的主要来源,并严重威胁到农村饮用水安全。猪场废水氨氮浓度高、处理难度大,如何采用经济高效的方法,去除氨氮使其达到排放标准,一直是猪场废水处理中面临的重要难题。 厌氧氨氧化是近年受到国内外水处理研究者广泛关注的新型生物脱氮技术,具有不需要外加有机碳源、节省供氧量、降低能耗等优点。虽然国内外研究者对厌氧氨氧化过程的脱氮机理、厌氧氨氧化菌的生理生化特性等进行了多方面的研究,但已有的报道大多以模拟废水为研究对象,以猪场废水为研究对象的报道,在国内外文献中极少有报导。 本论文以猪场废水为主要研究对象,考察了猪场废水的亚硝化过程、厌氧氨氧化的启动过程,并对亚硝化和厌氧氨氧化联合用于猪场废水脱氮进行了探索。 1.论文首先研究了猪场废水的亚硝化过程,考察了废水水质和主要运行条件对亚硝化过程的影响。实验表明:(1)亚硝化阶段反应时间为8到10h时,出水中氨氮和亚硝酸盐浓度比可达到1:1~1:1.23,满足厌氧氨氧化反应对二者比例的要求;达到前述要求时,氨氮去除率达到58.3~65.6 %,亚硝化率在整个过程均保持在97 %以上,COD去除率在59.2~68.6 %;(2)曝气量(溶解氧)对亚硝化过程影响显著,随着曝气量增大,达到厌氧氨氧化要求的氨氮与亚硝酸盐氮浓度比例所需水力停留时间τ越短,pH出现明显下降的时间越短;(3)τ对应的pH在7.8~8.1之间,无需进行pH调节即可满足厌氧氨氧化反应对pH的要求;(4)氨氮和COD降解过程遵循一级反应动力学,氨氮和COD降解的速率常数分别为0.0656~0.0724 1/h和0.0491~0.0664 1/h。 2.在进行亚硝化过程研究的同时,以模拟废水为试验对象,进行厌氧氨氧化启动研究。以反硝化污泥和养殖厂储水池厌氧底泥的混合污泥作为接种污泥,历时大约100天,培育出具有厌氧氨氧化活性的污泥,氨氮和亚硝酸盐氮最高进水浓度分别为223.8 mg/L和171.4 mg/L,去除率最高分别达48%和41.5%,此时二者消耗比例为1.33:1。 3.在猪场废水的亚硝化研究完成和厌氧氨氧化过程初步启动成功后,在模拟废水中逐步加入猪场废水的亚硝化处理出水,逐步实现亚硝化和厌氧氨氧化的组合。亚硝化出水添加到厌氧反应器后,厌氧氨氧化反应仍可继续进行,且去除效率逐步提高。研究发现添加的亚硝化出水中携带的亚硝化细菌在厌氧氨氧化菌膜外层生长并累积,增加了厌氧氨氧化反应基质的传质阻力,妨碍了厌氧氨氧化效率的提高。 4.亚硝化-厌氧氨氧化实际工程应用探索中,生物接触氧化池可在有效去除废水中的有机物的同时实现亚硝化,出水中氨氮和亚硝酸盐比例平均为1.10,可满足后续厌氧氨氧化的要求;在适宜的进水浓度和温度下,ABR池出现了厌氧氨氧化启动的迹象;研究同时发现,水质的波动和气温的变化是工程中影响厌氧氨氧化菌活性的重要因素。 论文的主要创新点在于:(1)以猪场废水为研究对象,以实现厌氧氨氧化为目标,对亚硝化过程进行了比较详细的考察,获得了亚硝化出水满足厌氧氨氧化要求的工艺条件,通过对其COD和氨氮降解过程的考察,得出亚硝化阶段COD降解和氨氮去除的动力学模型;(2)对亚硝化-厌氧氨氧化处理猪场废水进行了探索,确立了影响其污染物去除率稳定的重要因素。 论文的上述研究成果,为厌氧氨氧化技术的实用性研究提供理论依据。 Piggery wastewater, which is characterized by high concentration of COD、ammonium and suspend substance, has become a most important source of non-point source pollution and also severely threats drinking water security in rural area. How to discharge piggery wastewater with the ammonium concentration meeting standard by economical and effective method? This is the most urgent problem in piggery wastewater treatment. As a new biological nitrogen removal technology, Anammox process has been paid more and more attention by researchers all over the world. Anammox has advantages of no need of organic carbon addition, low oxygen consumption and energy consumption. Plenty of investigations have been carried out to the mechanism, physiological and biochemical characteristic of bacteria about Anammox. Most of researches focused on synthetic wastewater, there is rare report about its application in piggery wastewater. In this paper,experimental studies were performed to investigate Sharon process in treatment of piggery wastewater,the start up process of Annammox using synthetic wastewater were studied, the feasibility of applying Sharon-Anammox process in the nitrogen removal of piggery wastewater was evaluated. 1. Sharon process of piggery wastewater was firstly investigated to analyze the effects of water quality and main running parameters, which meet the NH4+-N to NO2--N ratio requirement of successive Anammox. Results showed: (1)During Sharon Process,after 8~10 hours’ reaction the NH4+-N to NO2--N ratio in effluent reached 1:1.0~1:1.23, when the removal percentage of NH4+-N was 58.3~65.6 %, a semi-nitration rate of above 97 % was achieved during the process; meanwhile 59.2~68.6 % of the COD was also removed. (2)The aeration rate(oxygen) had obvious effect on the hydraulic retention time(τ) which met the NH4+-N to NO2--N ratio requirement of Anammox. As aeration rate increased, the hydraulic retention time(τ) was shortened. (3) The pH corresponding to τ was between 7.8 and 8.1, thus it needed no artificial adjustment. (4) The reduction of ammonia and COD followed the first-order reaction kinetics. The velocity constants of ammonia and COD were 0.0656~0.0724 1/h and 0.0491~0.0664 1/h, respectively. 2. The startup of Anammox process using the artificial wastewater was performed simultaneously with Sharon. The aim was to investigate the running parameters of Anammox and make foundation for the combination stage. By using the mixture of denitrifying sludge and anaerobic sludge in tank of the breeding factory, sludge of Anammox activity was cultivated in UASB after 100 days. The removal percentage of NH4+-N and NO2-N were up to 48% and 41.5%, respectively, when the NH4+-N and NO2-N influent concentration were 223.8 mg/L and 171.4 mg/L, respectively, the NH4+-N and NO2-N removal rate was 1.33:1. 3. After investigation of Sharon and startup of Anammox, effluent of Sharon process was added into the synthetic wastewater to combine Sharon and Anammox step by step. It took some time after the addition of Sharon effluent that Anammox reaction continued and the removal rate kept increasing. It indicated that nitrifying bacteria were carried by the Sharon effluent cumulated in the outer layer of Anammox. This enhanced transfer resistance of Anammox reaction and the increasing removal rate was restrained. 4. In the bio-contact oxidation pond of practical project, Sharon process were carried out successfully and organic compounds were removed effectively. An average NO2-N/ NH4+-N rate of 1:1.0 was achieved in the effluent, which met the requirement of successive Anammox. Under condition of suitable influent concentration and temperature, there was evidence that Anammox could start up in ABR. The variety of wastewater and temperature had great affects on Anammox activity in practical engineering. Innovation of this paper: (1) The Sharon process for treating piggery wastewater was discussed in details. Technological parameters that met requirement of Anammox were obtained. The dynamic models of COD and ammonium removal in the process were educed. (2) Sharon-Ananmmox for treatment of piggery wastewater was investigated, and the primary influencing factors was studied. This paper could be a theoretical consult for research of Anammox utility.
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恶臭假单胞菌;异养硝化-好氧反硝化;自养硝化;生活污水脱氮;Pseudomonas putida;heterotrophic nitrification-aerobic denitrification;autotrophic nitrification;nitrogen removal for domestic wastewater treatment
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造纸行业是造成我国水环境有机污染物的重要污染源之一,其水污染的特点是小厂多、草浆多、工艺落后、污染扩散面广、造成废 水排放量大,每年排放的废水量约39亿立方米,占全国工业废水排放量的1/6,其中有机污染物(以BOD5计)160万吨左右,约占全 国工业废水中有机污染物总量的1/4。尤以占全国制浆造纸行业90%以上的碱法草浆造纸厂的蒸煮黑液量大面广,除含有机物外,还 含有木质素、残碱、硫化物、氯化物等污染物,属于PH值高、色度深、难于治理的高浓度有机废水,对水体污染特别严重,各地要 求治理呼声很高,急待研究并尽快找出各种有效的治理途径。对于碱法草浆蒸煮,黑液高浓度废水的治理,有各种方法,根据国内 的研究进展和我们已有试验工作表明,最经济有效,具有实用价值,在生产上可获得成功是厌氧处理法。近10多年来,国外关于高 效厌氧处理技术研究进展迅速,并出现了多种多样的工艺设备,如高效厌氧生物反应器,并在实用化方面取得了很大成绩,建立了 生产性装置,达到了高负荷运行,效果良好。本试验是根据我们已有研究基础,针对我国国情,对小型制浆造纸厂水污染防治除了 开发碱回收及各种综合利用技术外,要特别加强废水(废液)实用技术研究的指导思想,本试验采用改进型的上流式厌氧污泥床反应 器,设计了两种试验方案,通过试验结果如下。1. 试验方案I—碱法草浆黑液酸化和厌氧发酵I号UASB反应器动态模型试验结果表 明:(1). 采用中温35℃±1℃高效厌氧反应器USAB内装有填料(陶粒)和三相分离器,具有保持高浓度生物量和防止污泥流失的特点 ,污泥浓度Vs 可达30%以上,因而具有高效、节能、产能、滞留期短的优点,当进水CODcr在7500-10000mg/l,HRT由7天缩短到3天 ,有机容积负荷在1.22gCODcr/l·d-3.43gCODcr/l·d时,CODcr平均去除率可达55%-45.5%,最高CODcr去除率可达60.2-63.5%, BOD5去除率可达75.9-83.2%,沼气容积产气率可达0.29-0.67l/l·d,每克CODcr转化为沼气产率达0.39-0.48l/gCODcr·d,CH4含量 65.8-75.5%。厌氧发酵出水再用化学法进行后处理脱除难降解的木质素,CODcr总去除率达80%以上。(2). 动态试验结果表明:采 用酸化—厌氧发酵处理黑液工艺合理,技术路线可行。2. 试验方案II—黑液用化学法(Hcl)去除木质素进行厌氧发酵,II号UASB反 应器动态模型试验结果表明:(1). 采用中温35℃±1℃高效厌氧反应器UASB(内有软填料),当进水CODcr7000-13000mg/l左右,HRT 由6天缩短到1天,有机负荷由0.98gCODcr/l·d增加到11gCODcr/l·d时,COD平均去除率均可稳定在70-77%,BOD5去除率为87.3- 93.1%,沼气容积产气率0.21-2.6l/l·d,每克CODcr转化为沼气产率为0.39-0.48l/gCODcr·d,高的可达0.53l/gCODcr·d,转化 率较高,CH4含量63-70%。(2). 试验证明碱法草浆黑液物化预处理—厌氧发酵处理的技术路线也是可行的,工艺合理、效果较好。 在有条件的工厂可采用。3.厌氧发酵阶段几大类群微生物计数表明:(1). 当发酵工艺和运行处于相对稳定状态时,微生物群体的 组成也达到相对的稳定,各类微生物之间保持动态平衡关系。当产乙酸菌的数量为107-108个/ml时,产甲烷菌的数量为105-106 个/ml,当产乙酸菌数量为106-107个/ml时,产甲烷菌的数量为103-105个/ml。(2).稳态运行条件下,黑液预处理为甲烷发酵创造 了有利的生态环境,获得了较好的处理效果和较高的COD转化为沼气的产率0.39-0.48l/g·CODcr·d,反应器中形成较为稳定而数 量较下水污泥中高1-2个数量级的厌氧发酵微生物区系组成。这一结果为黑液厌氧发酵提供了微生物理论依据。Paper industry is one of the important pollution source of water environment in our country. Its character of water pollution is many small factories, much grass pulp, disadvantageous technique, large preading area of pullution. Its effluent makes up 1/6 of whole country's industry wastwater. Its organic pollutant accounts 1/4 of whole country's. Alkaline grass paper pulp effluent with pollutants such as ligoin, remaining alkali sulfide, chloride besides organic material, is a kind of high concentrate organic wastewater which has high PH walug, dark colour and is difficult in treatment. There is urgent require to find ways to treat the wastewater. There are different ways to treat alkaline paper grass pulp effluent. According to the research advances and our experiment work, the most economical and useful way is anaerobic degradation which was advanced quick in last ten years. In the control of waste water of small pulp paper mill, the study of wastewater utilization technology should be emphasized, besides alkaline retrieving and different kinds of comprehensive utilization technology. Our experiment used modified UASB(Upflow Anaerobic Sludge Blanket Reactor). Two kinds of plan were disgned. The results are lined below. 1. The first experiment plant-aciding black pulp effluent and methanogenic digestion. The dynamic model experiment results of I-UASB reactor showed: (1)The mesophilic(35℃±1℃)high effect UASB reactor having haydite and threee state seperation in it had the character of keeping high bioimass concentration and preventing losss of sludge. It had advantages of high effect, energe saving, energe prodcing and short HRT(Hydroulic retention time). When the influent COD was 7500-10000mg, HRT was shortened from 7 days to 3days, organic loading rate was 1.22g-3.43COD/l· d, the average COD removal efficiency was 55%-45%. The highest COD efficiency was 60.2-63.5%, BOD removal of 75.9 -83.4% was achieved. Biogass production rate were up to 0.29-0.67l/l·d. Biogass converted efficiency from every gram of COD could reach 0.39-0.48l/gCOD·d. Methane content was 65.0-75.5%. Chemical method was used to deplate lignin in anaerobic digestion effluent. Total COD removal efficiency could be more than 80%. (2)Using aciding annaerobic digestion to treat the black effluent was reseanable in technique and technology. 2. The second experiment plan-anaerobic digestion was used after the chemical method was used to deplate lignin in the black effluent. The result of dynamic experiment of II-UASB reactor showed: (1)High effect mesophilic (35℃±1℃)UASB reactor having soft slaffing in was used. When influent COD was about 7000-13000mg/l, HRT was shortened from 6 days to 1 day and organic loading rate was increased from 0.90 to 11g COD /l·d, average COD removal efficiency remained stable on 70-77%. BOD, removal efficiency was between 87.3-93.1%. Biogass production rate was 0.2-2.6l/l ·d .Biogass converted efficiency from a gram of COD was 0.39-0.481/gCOD·d with the high value of 0.53l/gCOD·d. Methane content was 63-70%. (2)The way that using physical, chemical Pre-treatment-anaerobic digestion to treat alkaline black effluent is feasible and can be used in some factories when the condition exists. 3. Counting of several class of microoganisms in anaerobic digestion stage showed: (1)As the disgestion was in stable motion, the compositon of microorganic colony could get relative stable. Dynamic balance was remaining among different kinds of microorganism such as methanogenic bacteria, Acidogenic bacteria, sulfate reducing bacteria, and heterotrophic bacteria. (2)Under stable motion, the pre-treatment of black effluent produced favourable eco-enviroment for methanegenic digestion. Good treatment effect and high biogass convertent efficiency from COD(0.39-0.48l/g·COD· d)were gotten. Some stable and high quantity(10-100times more than sewage sludge)microorganism colony were formed in the reactor. This result provided theoretical basis for anaerobic digestion of black effluent.
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经过细心的条件选择实现了无甲烷条件下甲烷氧化菌沼气甲基弯菌81Z(methylosinus methanica 81Z)利用C2化合物的生长,同时 发现二碳代谢中间产物甘氨酸的胞外积累及对生长的抑制作用。又在此基础上从81Z原种中富集得到一株菌81Z-A,兼性生长能力大 幅度提高,而且除乙酸外又能利用丙酮酸、苹果酸、柠檬酸、葡萄糖而生长。对细胞氧化各种有机底物时氧吸收的测定及酶分析结 果发现了在其它甲烷氧化细菌中未曾发现的异柠檬酸裂解酶和苹果酸酶的存在,表明81Z除了具有通常II型菌的碳代谢途径外,具 有特殊的补偿代谢途径——乙醛酸支路以及从乙酸生糖的回补途径。因此推证其兼性生长的能力是固有的,从而说明了甲烷氧化菌 的专一性概念没有普遍意义。说明了81Z还能在含有二碳的培养基中厌氧生长,包括细胞的分裂和增值行为。虽然这种厌氧生长还 很弱,但至少可以说明它不是严格好氧的,这对于传统的关于甲烷氧化菌的严格好氧的概念是一个冲击。81Z正常条件下是利用甲 烷而生长的,当供给它乙酸、乙醛酸和丝氨酸时能促进含C-C键有机物氧化的活性,而对甲烷单加氧酶和其它C2化合物的氧化有抑 制或阻遏作用,对碳同化的丝氨酸途径的关键酶羟基丙酮酸还原酶有阻抑作用。同时也证明了81Z的甲烷单加氧酶和甲醇氧化活性 可被甲烷、甲醇所诱导,而因甲酸而降低。The growth of Methylosinus methanica 81Z on C2-compounds without methane was realized by selecting suitable conditions. The intermediate product Gly from its C2 metabolism was found to accumulate out cells and inhibit its growth. 81Z-A, which was obtained from 81Z by richening, could grow on C2- compounds rapidly. It can even grow on pyruvate, malate, citrate and glucose. The results of measurements of oxygen consumption by cell suspensions in the presence of various organic compounds and the results of enzyme assays of detected activities of isocitrate lyaze and malic enzyme in cell extracts which were not found in other methantrophs showed that 81Z possesses not only the regular carbon metabalic pathways but also some peculiar anaplerotic pathways--the glyoxylate cycle and the gluconeogenic pathway from acetate. As a consequence of these studies, its ability of facultative growth is inherent. Therefore, the concept of obligate dependence on C2- compounds of methanotrophs is not of universal significance. The ability of 81Z's growth(including desintegration and proliferation behaviour) on C2-compounds anaerobically was also demonstrated. Despite of the weakness of this growth, at least it could be said that 81Z is not strictly aerobic. This is a strike to the traditonal concept about the strictly aerobic action of methanotrophs. Regularly, 81Z grows on methane. The presence of acetate, glyoxylate and serine could increaze its ability of oxidizing the organic coumpounds containing C-C ponds. In contrast, they could inhibit the activities of MMO and other C2-compounds oxidation, they also repressed the key enzyme hydroxypyruvate reductase of the serine-pathway for carbon assimilation. At the some time, it was testified that the activities of MMO and methanol oxidation were inducible by methane or methanol and were lower in the presence of formate.
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本文研究了两种微生物及其组合沥取、回收用微生物法治理电镀铬废水产生的铬污泥中的铬。铬污泥富含C、N、O,含铬量为13%, 经X-光电子能谱分析铬以三价态(氢氧化铬)存在。二种微生物分别从一酸性矿水和酸性污泥中分离筛选得到,经鉴定为硫杆菌属 (Thiobacillus Beijerinek)的两个不同种,一为氧化亚铁硫杆菌(Thiobacillu ferrooxidans, TF), 另一为氧化硫硫杆菌 (Thiobacillus thiooxidans, TT)。研究并比较了不同微生物对污泥中铬的沥取能力,结果表明,TT菌沥取铬效率最高。振荡、动 态淋滤、静置等沥取方式经过研究表明动态淋滤为最佳,室温条件下(15-20℃),污泥浓度为20g/L时,总铬沥出率达60%时所需时 间:动态淋滤为48.5h,振荡和静置方式分别为91.22,81.6h。研究了不同温度、不同起始PH、不同污泥浓度及非成熟菌液对微生 物沥取能力的影响:(1) 沥取前期,温度对铬的沥出影响较大;微生物沥取反应基本属一级反应;温度与反应速率的关系基本符合 Arrhenius方程,但沥取后期这一特点并不突出。(2) 沥取液最适起始PH为菌液自然PH;PH值的人为改变将使铬的沥出大大降低。 (3) 污泥浓度与铬的沥出呈正相关,但浓度高于30g/L时,铬的沥出量不再增加。(4) 非成熟菌液沥出铬的能力较差,但沥取液中 微生物生长繁殖较为活跃。总结微生物沥取反应最佳沥取条件为:TT成熟菌液、污泥浓度10g/L、温度25-36℃、动态淋滤方式,此 时铬几乎可100%从污泥中沥出。经扫描电镜分析,沥取开始时,微生物紧密吸附于污泥颗粒表面上,表面紧密吸附为微生物发挥功 能提供了基础。微生物沥取污泥中铬的反应机理推测为:硫细菌代谢产硫酸或氧化Fe2+成Fe3+,利用酸,Fe3+ 及自身氧化酶系统 氧化污泥中Cr3+为Cr6+,Cr6+溶出结晶为CrO3。This paper has studied bioleaching and recovery of Chronium(Cr)from electroplating sludge by two consortum of bacteria and their combination, with sludge produced by microbiological process treating electroplating wastewater containing Cr as material. The share of Cr is 13% and its state is Cr (OH)3 in the sludge. One of the bacteria in the paper was isolated from acid sewage sludge and the other was from acid mineral water. The former was tested and determined as Thiobacillus ferroxidans(TF) and the latter was Thiobacillus thiooxidans(TT). Different microorganisms, responsible for the metal leaching activity, have great influence on the efficiency of leaching. The results showed that TT has biggest power. Experiments were conducted to examined effects of three different ways of leaching(Shaking, Down-leaching, Static-leaching). When temperature was in-door's (15-20℃)and concentration of the sludge was 20g/L, the bioleaching time required to reach 60% of Cr solubilization with the above three ways were 91.2, 48.5, 81.6h respectively. Down-leaching was proved to be the most efficient. The influence of different temperature, initial PH, concentration of the sludge and non-mature inoculum had been studied. The results obtained reveal that: (1) The variation of temperature is important during the time from initial to middle of leaching. The reaction of bioleaching belongs to first-order. The relation between the bioleaching rate constant(In k)and temerature can be expressed by Arrhenius function. (2) The fittest initial PH is the nature PH of mature inoculum. Any alteration with it could cause clearly negative effection. (3) The concentration of the sludge can make strong influence on the bioleaching efficiency. But when the concentration is above 30g/L, the increasing of Cr in the solution is little. (4) If non-mature inoculum acts as the bioleachin microorganism, little quantity of Cr would be gained from the sludge. But the micormass in the solution is very active. The results from electron microscope showed that microorganisms adhered to the surface of the sludge and the adherence was the first stage of the bioleaching. Some salts of Cr can be obtained afer the water of the bioleaching solution being evaporated. By analysing the results of experiment with X-Ray spectroscopy, the salt was identified as CrO3. The recovery rate of Cr is 78.4%.
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单宁是一种典型的有毒难降解污染物,在制革、造纸、制药、印染等行业废水中广泛存在,对水环境造成污染并且影响废水生物处理效果。本研究针对含单宁废水生物处理效率低、较高浓度时微生物受抑制且污泥容易膨胀等问题,采用超声和磁粉来强化含单宁废水生物处理,研究超声和磁粉对微生物活性、污染物去除及污泥沉降性能的影响,并对其作用机理进行了分析和探讨。 研究结果表明,活性污泥系统中单宁酸容积负荷可以达到1.8kgCOD/(m3·d),单宁酸和COD去除率分别达到85.2%和79.6%,但如果负荷进一步增大则微生物活性迅速降低。系统在pH 5~8、温度20~35℃、DO>1 mg/L的条件下具有较好的单宁酸降解效果和处理稳定性。单宁降解动力学参数为:μmax =0.208h-1;Ks=226mg/L;Ki=522mg/L;kd=0.0092h-1;Y =0.594。 磁粉对系统处理效果和污泥沉降性能有一定的促进作用,且效果要优于外磁场。适宜的磁粉粒径和投加量分别为0.05~0.15mm和1.0g/L,COD去除率比对照系统提高6.4%,SVI降低28.6%,污泥絮体结构紧密。磁粉强化主要是通过其对污泥菌胶团的凝聚、吸附作用以及对微生物活性的强化作用实现。 在适当强度(0.4W/cm2)和辐照时间(20min)的超声作用下污泥絮体和细胞膜通透性增大,酶分泌也增多,系统的COD去除率比对照提高了8.8%,单宁酶酶活提高了11%。但超声也使污泥絮体结构松散,沉降性能下降,SVI比对照系统升高9.3%。 由于污泥流失加剧导致污泥浓度相对较低,声磁联合强化系统相对于磁粉强化系统其处理效果并没有提高。但相对于单纯活性污泥系统,声磁联合作用下系统处理效果、污泥沉降性能以及系统运行稳定性都得到明显改善。本研究为难降解废水的生物处理提供了一个新的思路。 Tannins are typical refractory and toxic pollutants that commonly exist in wastewater from dye, medicine, paper and leather industries and cause many problems associated with environmental pollution and biological treatment of wastewater. Biological treatment efficiency of tannin-containing wastewater is usually low owing to its biological toxicity and low biodegradability, microbes are usually inhibited under high tannin concentration and sludge bulking frequently occurs. In this study, ultrasound and magnetic powder were used to improve the biological treatment performance of simulated tannic acid-containing wastewater. The effects of ultrasonic irradiation and magnetic powder on microbial activity, tannic acid degradation rate and sludge sedimentation were investigated. The augmentation mechanisms were analyzed and discussed. The experimental results showed that the microbes were prominently inhibited under high tannic acid concentration, but moderate degradation efficiency can be maintained under a tannic acid load of up to 1.8kgCOD/(m3·d), with the tannic acid degradation and COD removal percentage of 85.2% and 79.6% respectively. The highest degradation rates and treatment stability were achieved at pH range of 5~8, temperature range of 20~35℃ and DO concentration of above 1mg/L. The kinetic parameters were estimated, including: μmax =0.208h-1;Ks=226mg/L;Ki=522mg/L;kd=0.0092h-1;Y =0.594. The microbial activity, tannic acid degradation rate and sludge sedimentation were improved by adding Fe3O4 magnetic powder, and the augmentation performance was better than external magnetic field. The appropriate particle size and dosage of magnetic powder were found to be 0.05~0.15mm and 1.0g/L, respectively, under which the COD removal percentage was improved by 6.4% and SVI value decreased by 28.6%, and compact floc structure was observed. This was mainly caused by the flocculation and adsorption effects of magnetic powder against sludge floc and the stimulation of microbial activity under appropriate magnetic field. Under appropriate ultrasonic irradiation (ultrasonic intensity 0.4W/cm2, ultrasonic irradiation time 20min), the permeability of floc and cell membrane are improved, transfer of substrate and oxygen were reinforced; meanwhile, more enzyme were produced by microbes under the slight damage caused by ultrasound. However, the floc structure became loose under ultrasonic irradiation, leading to relatively poor sedimentation, with the SVI value 9.3% higher than the control system. Although the magnetic powder-ultrasonic irradiation combined augmentation system showed no improvement in treatment performance compared with sole magnetic augmentation system owing to its relatively low sludge concentration, it guaranteed the stable operation of system, meanwhile the tannic acid degradation and sludge sedimentation were significantly improved compared with sole activated sludge system. This study gives a new idea for biological treatment of refractory wastewater.
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畜禽废水是农村水环境污染的主要来源之一,其处理的难点在于脱氮。传统生物脱氮法具有能耗高、需大量外加碳源等缺点,开发低成本、高效率的新型生物脱氮技术具有重要意义。 本研究将短程硝化反硝化和厌氧氨氧化两种脱氮新技术结合,让前者为后者创造去除可降解COD、降低总氮负荷、调整pH、调整氨氮和亚硝酸盐氮浓度比例等进水条件,而后者可在无需外加碳源的条件下进一步脱氮,二者结合可成为高氨氮、低C/N废水脱氮的新途径。 试验以低碳氮比猪场废水为研究对象,首先进行了短程硝化反硝化预处理研究,同时启动并运行调控厌氧氨氧化反应器,最后以经过短程硝化反硝化预处理的猪场废水为进水,进行厌氧氨氧化脱氮考察。实验表明:(1)短程硝化反硝化作为厌氧氨氧化的预处理工序是可行的。猪场废水通过短程硝化反硝化,可以达到基本去除可生化COD、部分脱氮、控制出水氨氮和亚硝酸盐氮浓度之比在1︰1左右、pH在7.5~8.0的目的, COD和总氮平均去除率分别为64.3%、49.1%,出水可达到厌氧氨氧化反应的进水要求。(2)采用模拟废水启动厌氧氨氧化反应器,经过5个月左右的运行调控,反应器启动成功并稳定运行,最高总氮去除率为87.1%,总氮容积去除率最高达到0.14kg/m3.d;整个稳定阶段,氨氮、亚硝酸盐氮、硝酸盐氮的变化量之比为1︰1.21︰0.33。(3)经过短程硝化反硝化预处理的猪场废水厌氧氨氧化脱氮效果稳定,氨氮、亚硝酸盐氮、总氮、COD的平均去除率分别为93.0%、99.4%、84.6%、18.1%,处理效果与模拟废水处理系统相比无明显变化。(4)经过短程硝化反硝化预处理后,猪场废水中残留有机物成分在厌氧氨氧化反应过程中无显著变化,主要为酯类和烷烃类物质;残留有机物对厌氧氨氧化效果无明显影响。(5)采用PCR技术进行特殊功能菌种检测,结果表明模拟废水处理系统和猪场废水处理系统的菌群中均含有厌氧氨氧化菌和好氧硝化菌;通过blast比对,厌氧氨氧化菌扩增序列与未培养的Planctomycetales菌和Candidatus Brocadia fulgida菌16S rRNA部分序列相似性分别为95%、90%。(6)MPN法菌种计数结果显示,模拟废水处理系统和猪场废水处理系统的菌群中均含有硝化细菌、亚硝化细菌和少量反硝化菌,实验条件下的微生物系统是一个厌氧氨氧化菌与好氧硝化菌、反硝化菌共存的系统。 Poultry wastewater is one of the main source of water pollution in rural areas,and nitrogen removal is the most difficult part in treating poultry wastewater. There are some disadvantages in traditional nitrogen removal, such as high energy consumption and more additional organic carbon. It is important to develop ecolomical and efficient technologyies. Shortcut nitricfication/denitrification, as a pretreatment process, was combined with Anammox in this research, so that part of total nitrogen and most degradable COD could be removed by the former, and further nitrogen removal could be implemented by the latter. The combination of the two technologies was a new approach to treat wastewater with high ammonium and low C/N. Piggery wastewater with low C/N was treated in lab-scale experiment. Firstly, shortcut nitrification/denitrification was investigated, and Anammox reactor was started up successfully at the same time. Then piggery wastewater after pretreatment was treated by Anammox. The results showed :(1) It was feasible to take nitrification/denitrification as the pretreatment process of Anammox. By using this process, part of total nitrogen and COD were removed, the ratio of ammonium and nitrite reached around 1︰1 and the pH was about 7.8, which were favorable for Anammox. The average removal percentage of COD and total nitrogen were about 64.3% and 49.1%, respectively. (2) Simulated wastewater was used to start up Anammox reactor. The reactor was started up successfully within 5 months and stable performance was achieved. The highest nitrogen removal reached 87.1% and the biggest volumetric total nitrogen removal rate reached 0.14kg/m3.d. The average ratio of ammonium, nitrite and nitrate was 1:1.21:0.33. (3)Taking the effluent of shortcut nitrification/denitrification as the influent, the nitrogen removal efficiency of Anammox was stable, and the the average removal percentage of ammonium, nitrite, total nitrogen and COD were 93.0%, 99.4% , 84.6% and 18.1%, respectively, which had little difference with that by using simulated wastewater..(4) After pretreatment, the residual organic carbon in piggery wastewater showed no obvious change during the Anammox process, and the main organic compounds were saturated hydrocarbon and ester, which had no obvious negative effect on Anammox process.(5) By PCR technology, the existence of Anammox bacteria was confirmed and the aerobic nitrifying bacteria was found to coexist as well. The result of blast showed that the identities of Anammox bacterium to part of 16S rRNA sequence of uncultured Planctomycetales bacterium and Candidatus Brocadia fulgida bacterium were 95% and 90%, respectively.(6)By MPN method, nitrite oxidizer, ammonium oxidizer and denitrification bacteria were detected in both simulated and piggery wastewater treatment system of Anammox, and the microorganism system was composed of Anammox bacteria,aerobic bacteria and denitrification bacteria together.
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随着化工行业的发展,大量有毒有害难降解有机物随工业废水的排放进入环境,这些物质能够在环境中长期存在、积累和扩散,通过食物链对动植物的生存及人类的健康造成不良影响。本文以苯酚、对氯硝基苯、氯苯和十六烷为模拟污染物,以前期研制的功能菌剂为对象,经过紫外线线诱变筛选出优于出发菌株的功能菌,对诱变后功能菌的理化性能进行了研究,对菌种进行了鉴定,在此基础上,就其相互之间的微生态关系进行研究,为混合发酵提供理论基础,并就其最佳发酵条件及发酵参数进行了研究,最后对发酵产品的性能进行了检测。目前,国内外有关功能菌剂的研究还存在多方面的不足,主要包括:①由于多菌种混合发酵过程较为复杂,各菌之间存在复杂的相互作用,影响因素较多,关于菌种之间的相互关系研究得很少,环境功能菌剂的发酵方法大多采用单独发酵后混合的方式。单独发酵对原材料、设备和能源的利用率较低,对于多菌种制剂发酵,在设备、能源和原材料的方面造成的浪费更大,将会大幅增加菌剂的生产成本,影响多菌种功能菌剂的发展;②功能菌剂生产过程的质量控制方面研究得较少;③功能菌剂产品的稳定性、抗冲击性能研究得较少,对环境微生物制剂的研究主要集中在菌种选育和培养条件优化方面。 通过本论文研究,得到以下主要结论。 (1)在紫外线诱变处理中,用紫外线对发生一定程度退化的出发菌株进行诱变处理后,六株具有高效降解性能的菌株被筛选出来,诱变筛选出的菌株形态和ERIC-PCR指纹图谱与出发菌株相比发生了明显改变;而且诱变后的菌株对目标难降解底物的降解能力均得到改善,其中,FPN、FCB、F14、FEm对目标底物的降解率提高了20%以上;诱变后菌株经过7次连续传代接种后,对目标难降解底物的降解率无显著变化,具有一定的遗传稳定性。并对诱变后的功能菌进行了初步的鉴定,这6株菌都分别是芽孢杆菌。 (2)对诱变后的功能菌相互之间的微生态关系进行了研究,通过抑菌实验、生长量以及基质消耗量的比较,确定它们之间的生长关系是无害共栖关系,可以进行混合发酵。 (3)对该功能菌剂进行发酵培养条件研究,结果表明发酵培养基的最佳成分(g/L):葡萄糖 31.0g/L、玉米粉10.0g/L、磷酸氢二钾1.0g/L、硫酸铵1.1g/L、硫酸镁0.55g/L。通过研究不同的培养条件对菌体生长和降解性能的影响,确定了最佳培养条件:培养基初始pH7.5;最适温度32℃;培养基装液量125mL(250 mL三角瓶),以及培养时间对降解性能的影响,培养20 h的产物对降解最为有利。通过研究添加不同目标污染物对菌体生长和降解性能的影响,确定了添加目标污染物的最佳量以及最佳时间:苯酚投加量:1.125 g/L,对氯硝基苯投加量:0.1 g/L;最佳投加时间为发酵培养开始后4 h。 (4)以摇瓶分批发酵最优条件为基础,对FPN、F10、FCB、FNa、F14 和 FEm进行了摇瓶分批发酵试验。以摇瓶分批发酵试验数据为依据,对功能菌剂分批发酵动力学进行了研究,建立了菌体生长和基质消耗的动力学模型,拟合模型能较好的反映功能菌剂分批发酵过程。 (5)功能菌剂和活性污泥协同作用,可以提高系统的生物降解能力,功能菌剂投加量为2%,新鲜活性污泥3500 mg/L,降解24 h条件下,功能菌剂和活性污泥的协同作用对COD的去除率和对照组相比,最多的提高了36.8%。功能菌剂和活性污泥协同作用以及活性污泥的单独作用,其生物降解过程均符合一级反应动力学过程,功能菌剂和活性污泥协同作用的生物降解动力学方程为:,相关系数97%。采用SBR运行方式,引入功能菌剂的SBR系统明显能够改善和提高生物降解的效率。与仅有活性污泥的系统相比,系统对COD的平均去除率可以提高27.1%,同时,系统的耐负荷冲击以及耐毒害冲击的性能比仅有活性污泥的SBR系统强,特别是负荷冲击对引入功能菌剂的SBR系统影响很小。仅有活性污泥的SBR系统经过负荷冲击和毒害冲击之后,不能恢复到冲击之前的水平,而且系统有效作用时间的周期比引入功能菌剂的SBR系统相比大大缩短,而引入功能菌剂的SBR系统处理效果较为稳定,恢复能力很强。 Along with the development of industries, many recalcitrant organic chemicals have been discharged into natural environments together with wastewaters and can exist in waters, soil and sediments for a long time without degradation. These haz-ardous substances, their byporducts and metabolizabilities can be highly toxic, mu-tagenic and carcinogenic, thereby threatening animals, plants and human health through food chain. Consequently the removal of these compounds is of significant interest in the area of wastewater treatment. In this dissertation, the phenol, hydro-quinone, chlorobenzene and hexadecane treated as the model pollutants, the func-tional microorganism agent was used as the starting strains, they treated with ultra-violet light, and then the mutant strains with high degradation ability were screened out and identified primarily, the relationship between these stains were studied, the medium composition and fermentation conditions were optimized, the degradation ability of the fermented production was tested. The literature survey indicates that the study of the microorganism agent is far from complete and more information is re-quired on following problems. 1, Because of the complexity of relationship in mixed fermentation and the complicated factors, the study is hardly to process.2, There is a lack of information on the quality control of the producing process .3, And there is a lack of information on the stability about the microorganism agent. In this dissertation, the main results of the present study could be summarized as follows: (1)The degenerate starting strains were treated with the ultraviolet light, and six mutant strains with high biodegradation ability were screened out by using the me-dium with selective pressure of model pollutants. The mutant strains had great changes in colonialmorphology and ERIC-PCR fingerprinting. And the mutant strains got obvious advantages over the starting strains in degradation ability and over 20% improvement of removal rates was achieved for FPN、FCB、F14 and FEm. The de-gradation ability of the mutant strains was stable after seven generations. After that, the mutant strains were primarily identified as bacillus respectively. (2) The relationship between these mutant strains was studied. By the compari-son of antibiosis effect, biomass and consumption of substrate, the relationships were neutralism and they could be mixed fermented. (3) The optimized cultivation conditions were as follows: glucose 31.0 g/L, corn power 10 g/L, K2HPO4 1.0 g/L, (NH4)2SO4 1.1 g/L, MgSO4 0.55 g/L, initial pH7.5, temperature 32℃, working volume 125 mL/250 mL, and cultivation time 20h (con-sidering the time effect on degradation ability), adding pollutants phenol (1.125 g/L) and hydroquinone (0.1 g/L) into the broth at 4 h after cultivation. (4) Based on the above optimum condition, the batch fermentation was per-formed with strains FPN, F10, FCB, FNa, F14 and FEm in shake flask. The batch fermentation kinetics was studied based on the experimental data. Two kinetic models were constructed which could reflect the regularity of growth and substrate consump-tion in the process of batch fermentation. (5) The co-operation of functional microorganism agent and activated sludge could raise biodegradation of system by adding some microorganism agent and 3500 mg/L fresh activated sludge. Bioaugumentation by the addition of high effective deg-radation culture enhanced the treatment effect of SBR system and the COD removal rate was increased by 20%-36.8%. Its biodegradation matched first-order dynamical reaction equation, and the reaction equation was ln0.2327.391ct=−+. The micro-organism agent had the effect of optimization to activated sludge micro-ecosystem. The SBR system adding 2% microorganism agent, the average COD removal rate of that was increased by 27.1% and stronger anti-shock ability to load and toxicant were achieved (compared with SBR system just adding activated sludge). Especially the load-shock has barely effect to the SBR system adding microorganism agent. After the load and toxicant shock, the SBR system just adding activated sludge couldn’t come back to original level and the activated sludge micro-ecosystem was frustrated. The applying of microorganism agent increased biological activity and system’s re-sistance ability to load shock and toxicant shock.