热纤梭菌发酵产物的分析

分析了热纤梭菌（ＣｌｏｓｔｒｉｄｉｕｍＴｈｅｍｏｃｅｌｌｕｍ）ＡＴＣＣ２７４０５和ＮＣＩＢＩ１０６８２转化纤维素的产物，研究表明，热纤梭菌转经纯化纤维素的产物主要有酒精，乙酸，还原糖，ＣＯ２和Ｈ２，还原糖成分为木糖，纤维二糖和葡萄糖，经ＡＴＣＣ２７４０５转化后产生的木糖，纤维二糖与葡萄糖的比例为３．３：０．９：１经ＮＣＩＢ１０６８２转化后，则为７．９：３．２：１。     

酵母发酵条件的优化及其发酵造纸污泥产乙醇

优化了酿酒酵母Saccharomyces cerevisiae GIM-2发酵工艺条件并对其发酵造纸污泥产乙醇进行了研究。以模拟造纸污泥水解液中糖成分的混合糖为试验原料,采用响应面分析法优化酵母发酵生产乙醇工艺,得优化条件:温度33.1℃,pH值5.4,摇床转速50r/min,发酵24h糖醇转化率为38%。造纸污泥在纤维素酶作用下水解48h,纤维素转化率为58.2%,水解液在优化条件下发酵24h糖醇转化率为28.4%,产率达0.14g乙醇/g污泥,是理论值的37.3%。     

混合菌同步糖化共发酵造纸污泥产乙醇

对酿酒酵母（Saccharomyces cerevisiae）与重组大肠杆菌K011（Escherichia coli）混合菌同步糖化共发酵造纸污泥产乙醇进行了初步研究。在底物浓度为50g／L时,通过单因素实验和正交实验获得乙醇发酵的最佳条件：纤维素酶添加量25FPU／g底物,接种量为6％,酿酒酵母与重组大肠杆菌K011接种比例为1：1（细胞干重初始浓度分别为1．0g／L和0．3g／L左右）。发酵72h后,乙醇浓度为5．71g／L,产率达到0．114g乙醇／g污泥,达到理论值的42．5％。分别用酿酒酵母、K011单菌种发酵与双菌株组合发酵对比结果表明,混合菌发酵效果明显优于单菌种发酵。     

造纸污泥厌氧发酵生物产氢研究

以实验室造纸污泥堆肥腐熟肥为菌源、造纸污泥为底物进行厌氧发酵产氢实验.结果表明,造纸污泥经超声波预处理40 min,添加10 mL质量分数0.05％的三氯甲烷后,在36.5℃,pH值5.5 ～6.0条件下与实验室造纸污泥堆肥腐熟肥按质量比2∶1进行混合厌氧发酵,累积产氢量83.5 mL/g(挥发性固形物),H2浓度51.0％ ～67.7％,有机物利用率32.4％ ～43.8％.     

造纸污泥厌氧发酵生物产氢研究

以实验室造纸污泥堆肥腐熟肥为菌源、造纸污泥为底物进行厌氧发酵产氢实验。结果表明,造纸污泥经超声波预处理40min,添加10mL质量分数0.05%的三氯甲烷后,在36.5℃,pH值5.5～6.0条件下与实验室造纸污泥堆肥腐熟肥按质量比2∶1进行混合厌氧发酵,累积产氢量83.5mL/g(挥发性固形物),H2浓度51.0%～67.7%,有机物利用率32.4%～43.8%。     

制浆造纸污泥厌氧消化的研究进展

总结了近几年国内外制浆造纸污泥厌氧消化的研究进展。针对造纸污泥燃气化潜质,介绍了造纸污泥的主要成分、性质及厌氧消化过程中存在的问题,讨论了热、化学、生物和机械预处理方法对污泥厌氧消化产甲烷性能的影响,以期对以后的研究工作提供一定的借鉴作用。     

利用造纸污泥发酵产生生物气体甲烷

日本Chiba科学研究所科技人员研究了利用造纸污泥（PS）发酵产生生物气体甲烷的方法。PS由造纸过程中产生的纤维素和一些作为填料或颜料中的陶土物料例如滑石粉、方解石和高岭土所组成，其中，纤维素可用作发酵生产甲烷的原料。科研人员还研究了PS中纤维素与无机物的相互关系以及陶土无机物对纤维素发酵产生甲烷量的影响，     

造纸污泥的流变特性测试

以造纸污泥为研究对象,采用NXS-11型旋转黏度计在室温(23·5℃)条件下对质量浓度为55%、60%和65%的污泥进行剪切应力测试,获得不同剪切速率下对应的剪切应力和黏度值,得出造纸污泥的流变曲线,并回归出流变方程和黏度表达式。可以看出浓度为55%和65%污泥的流体类型为假塑性流体,60%污泥的流体类型为宾汉流体。     

热纤梭菌分解纤维素生产乙醇的研究进展

本文介绍了热纤梭菌的生理生化特性及发酵生产的研究进展，并对影响热纤梭菌发酵生产乙醇的因素以及乙醇等发酵产物对热纤梭菌的抑制作用作了概述。     

响应面法优化嗜热厌氧代谢工程菌发酵产乙醇的培养基

利用响应面法优化嗜热厌氧代谢工程菌产乙醇的培养基,在单因素实验基础上,采用Plackett-Burman 设计对影响嗜热厌氧代谢工程菌发酵产乙醇的重要培养基组分进行了筛选,确定主要影响因子为葡萄糖、木糖和酵母提取物.再用最陡爬坡实验逼近最大响应区域.最后用中心组合设计和响应面分析法,确定了主要影响因子的浓度.优化后的培养基组成为葡萄糖13.07g/L,木糖9.58g/L,酵母提取物3.78g/L,其他组分浓度同MTC培养基,不添加一水半胱氨酸盐酸盐和二盐酸吡哆氨.在此培养基条件下,乙醇产量和乙醇得率分别为(6.102±0.21)g/L和(0.38±0.012)g/g,是优化前产量的1.46倍.     

Enhanced biohydrogen production from sewage sludge with alkaline pretreatment

Batch tests were carried out to analyze influences of the alkaline pretreatment and initial pH value on biohydrogen production from sewage sludge. Experimental results of the impact of different initial pH on biohydrogen production showed that both the maximal hydrogen yield occurred and that no methane was detected in the tests of at the initial pH of 11.0. The final pH decreased at the initial pH of 7.0-12.5 but increased atthe initial pH of 3.0-6.0, probably due to the combination of solubilized protein from sludge and the formation of volatile fatty acids (VFAs) and ammonia during biohydrogen fermentation. The performance of biohydrogen production using the raw sludge and the alkaline pretreated sludge was then compared in batch fermentation tests atthe initial pH of 11.0. The hydrogen yield was increased from 9.1 mL of H2/g of dry solids (DS) of the raw sludge to 16.6 mL of H2/g of DS of the alkaline pretreated sludge. No methane and less carbon dioxide (0.8% of control) were present in the biohydrogen production from the alkaline pretreated sludge. These results clearly showed that biohydrogen production could be enhanced and maintained stable by the combination of the high initial pH and alkaline pretreatment. The mechanism of biohydrogen production from sewage sludge at high initial pH was therefore investigated because the results of this study were differentfrom previous studies of biohydrogen production. Results showed that protein was the major substrate for biohydrogen production from sewage sludge and that Eubacterium multiforme and Paenibacillus polymyxa were the dominant bacteria in biohydrogen production from alkaline pretreated sludge at an initial pH of 11.0. The combination of alkaline pretreatment and high initial pH could not only maintain a suitable pH range for the growth of dominant hydrogen-producing anaerobes but also inhibit the growth of hydrogen-consuming anaerobes. In addition, the changes in pH value, oxidation-reduction potential, VFAs and soluble COD during hydrogen fermentation were also discussed.     

苹果渣固态厌氧发酵制备生物质氢气的研究

以苹果渣为对象,进行固态厌氧发酵制备氢气的技术研究。考察了产氢菌的富集方式、苹果渣预处理条件、厌氧发酵条件对苹果渣产氢效果的影响。研究结果表明,产氢菌的最佳富集方法为:活性污泥在室温(25℃)和pH11.0条件下预处理1.5h,然后调整pH为7.0。苹果渣粉碎至2000μm,在浓度为1%的NaOH溶液中浸泡2h后,调整pH至中性;苹果渣(w):麸皮(w):水(w)=4:1:25,在此条件下,苹果渣最大产氢量为16.47mL/gTS(TS:totalsolid)。表明苹果渣在固态条件下具有发酵生物质气体的潜力。     

严格厌氧嗜热纤维梭状芽孢杆菌产纤维素酶条件的优化

该文以厌氧瓶和发酵罐研究了嗜热纤维梭状芽孢杆菌(Clostridium thermocellum)在厌氧条件下产纤维素酶的发酵条件,发现在厌氧发酵瓶中,在培养温度55℃、初始培养基p H 7、发酵60 h为最佳产酶条件,此时测得酶活为5. 12 U/m L。在放大到5 L发酵罐上的厌氧分批发酵条件下的生长曲线、糖耗、补料时间和添加碳源的研究结果发现,培养到16 h后,菌体进入指数生长期,糖耗最大,并确定最佳补料时间为16～48 h,纤维二糖为最佳补料碳源,酶活最高达16. 56 U/m L,显著高于发酵瓶。研究结果为利用嗜热纤维梭菌进行工业化发酵生产耐高温纤维素酶提供了依据。     

利用造纸污泥制备的絮凝剂性能研究

从造纸污泥中提取木质素,对其进行化学改性制备木质素磺酸钠和木质素季胺盐,分别作为絮凝剂处理酿造废水,结果表明,3种絮凝剂均可处理酿造废液,效果为木质素季胺盐最好,木质素磺酸钠次之,木质素最差.木质素季胺盐作为絮凝剂处理废水的最佳工艺条件为：废水pH=3.5,投加量为0.7 g/L,常温,此时CODCr和浊度去除率分别可达70.17%和98.01%.     

造纸厂水处理污泥基本性质及热解特性研究

本论文分别对初沉污泥、生化污泥及深度处理污泥的基本物化性质及热解特性进行了研究,并进一步采用coaAs-Redfern法描述了热解过程,计算了三种污泥的热解动力学参数。动力学研究结果表明：造纸厂水处理初沉污泥有机物热解主要区域的反应级数为2,二沉污泥及深度处理污泥的反应级数为5,三者的活化能分别为：43．80kJ／mol、52．74kJ／mol 及17．16kJ／mol,频率因子分别为：1．56×10^6min-1、1．18×10^7min-1、2．60×10^8min-1。     

造纸污泥性质的研究

分析了造纸污泥的基础性质,包括含水率、有机物含量、pH值、干污泥中纤维含量、干污泥中灰分含量、干湿污泥中细菌、干污泥中CHSN含量.结果显示,污泥含水率高,有机物含量大,其中大多是纤维,pH值为中性.污泥中有大量细菌等微生物,蛋白质含量与市政污泥相当.此研究为造纸污泥的资源化利用提供理论基础.     

丙酮丁醇梭菌发酵小麦麸皮生产丁醇

对丙酮丁醇梭菌(Clostridium acetobutylicum)8016发酵小麦麸皮或麸皮混合其他非粮淀粉质原料生产丁醇进行了研究。实验结果表明,当初始糖浓度为55g/L时,以纯麸皮为底物,发酵终点总溶剂达到21.43g/L,丁醇13.08g/L,糖醇转化率39.57%;以麸皮混合红薯、木薯为底物,发酵终点总溶剂达到22.37g/L,丁醇13.24g/L,糖醇转化率为39.95%,均能达到传统玉米醪发酵丁醇水平。证明小麦麸皮作为一种粮食加工废弃物完全可以替代粮食用于丙酮丁醇发酵。     

Inhibition of biohydrogen production by undissociated acetic and butyric acids

Glucose fermentation to hydrogen results in the production of acetic and butyric acids. The inhibitory effect of these acids on hydrogen yield was examined by either adding these acids into the feed of continuous flow reactors (external acids), or by increasing glucose concentrations to increase the concentrations of acids produced by the bacteria (self-produced). Acids added to the feed at a concentration of 25 mM decreased H2 yields by 13% (acetic) and 22% (butyric), and 60 mM (pH 5.0) of either acid decreased H2 production by >93% (undissociated acid concentrations). H2 yields were constant at 2.0 +/- 0.2 mol H2/mol glucose for an influent glucose concentration of 10-30 g/L. At 40 g glucose/L, H2 yields decreased to 1.6 +/- 0.1 mol H2/mol glucose, and a switch to solventogenesis occurred. A total undissociated acid concentration of 19 mM (self-produced acids) was found to be a threshold concentration for significantly decreasing H2 yields and initiating solventogenesis. Hydrogen yields were inhibited more by self-produced acids (produced at high glucose feed concentrations) than by similar concentrations of externally added acids (lower glucose feed concentrations). These results show the reason hydrogen yields can be maximized by using lower glucose feed concentrations is that the concentrations of self-produced volatile acids (particularly butyric acid) are minimized.     

利用造纸污泥制备木素系缓蚀阻垢剂的研究

对造纸污泥中提取的木质素进行磺化改性,将所得木质素磺酸盐与丙烯酸进行接枝共聚,确定优化工艺条件为:K2S2O8作引发剂,m(木质素磺酸钠):m(丙烯酸):m(K2S2O8)=10:4.8:1.2,pH=9,80℃下反应3 h.改性后所得产品的缓蚀阻垢性能明显提高,缓蚀率和阻垢率分别可达63.5%和40.5%.