ORP调控对葡萄糖和果糖混合底物丁醇发酵的影响

采用氧化还原电位(oxidoreduction potential,ORP)调控以模拟菊芋块茎酸解液(葡萄糖和果糖混合糖)为底物进行的丙酮丁醇发酵过程,能够有效控制"酸崩溃"现象的发生。已通过实验确定最佳调控策略为控制整个发酵过程的ORP不低于-460mV。本研究在最佳调控策略下,发酵终点丁醇浓度从3.39g/L提高到11.65g/L,残糖浓度从30.82g/L降低到1.38g/L。对比ORP调控组和对照组发现,ORP调控能够改变发酵过程中细胞内还原力水平,能量状态和代谢流向,因此ORP调控能有效防止"酸崩溃"现象发生,调节菌体生长和溶剂产量。ORP调控策略应用于以葡萄糖和果糖混合糖为底物的丁醇发酵具有操作可行性,是一种简便而有效的工艺优化手段。     

SBR法短程硝化及过程控制研究

考察了采用SBR法处理氨氮浓度较高的化工废水时供氧方式对硝化过程中DO、ORP和pH值变化规律的影响。试验结果表明，在曝气量恒定的条件下，可以硝化过程中DO和pH值升高速率的不同表征反应的进程程序，即当氨氮浓度接近零时，DO和pH值升高速率或变化幅度加大，二者可以作为SBR硝化反应时间的控制参数，而ORP值对SBR硝化反应结束的批示作用不是很明显；在DO量恒定的情况下，pH值在整个硝化反应过程中都是缓慢下降或趋于稳定的，当硝化反应结束时突然升高，因此pH值也可作为SBR硝化反应时间较好的控制参数，而ORP值在硝化反应的初期快速升高，之后升高的速度越来越慢直至趋于平稳，它对SBR硝化反应结束的指标作用同样不是很明显。     

生物冶金ORP与关键工艺参数关联规则的挖掘

针对生物冶金提金率难以提高这一难题,通过深入分析生物冶金工艺,依据工艺现场实测数据库、新型数据分析方法和数据挖掘方法,得到氧化还原电位(ORP)与工艺过程可控因素间的可描述数学关系,为可控工艺参数的优化控制提供指导依据,进而提高生物冶金提金率。     

Controlled oxidation-reduction potential on dark fermentative hydrogen production from glycerol: Impacts on metabolic pathways and microbial diversity of an acidogenic sludge

The oxidation-reduction potential (ORP) is an important factor in H₂ production via dark fermentation however its effect over microbial diversity in an acidogenic sludge has not, been well studied. This work studies the effect of ORP controlled by hydrogen peroxide and potassium ferricyanide on continuous hydrogen production and microbial diversity in an acidogenic sludge fed (HRT 12 h and pH 5.5) with glycerol. Results show that the more oxidizing ORP control environment (?540 mV) improves H₂ yield by 50–70% (0.31–0.51 molH₂/mol glycerol) over non-ORP control conditions. Oxidizing ORP values were shown to enrich microorganisms of the genus Clostridium, which have been linked to high H₂ yields. Therefore, controlling ORP in an acidogenic sludge was shown to directly modify microbial diversity at the genus level, and could likely to indirectly regulate metabolic function. Additionally, metabolic pathways were regulated by the kind of agent used.     

Enhancement of Escherichia coli bacterial biomass and hydrogen production by some heavy metal ions and their mixtures during glycerol vs glucose fermentation at a relatively wide range of pH

Escherichia coli growth and H₂ production were followed in the presence of heavy metal ions and their mixtures during glycerol or glucose fermentation at pH 5.5–7.5. Ni²⁺ (50 μM) with Fe²⁺ (50 μM) but not sole metals stimulated bacterial biomass during glycerol fermentation at pH 6.5. Ni²⁺+Fe³⁺ (50 μM), Ni² +Fe³⁺+Mo⁶⁺ (20 μM) and Fe³⁺+Mo⁶⁺ (20 μM) but not sole metals enhanced up to 3-fold H₂ yield but Cu⁺ or Cu²⁺ (100 μM) inhibited it. At pH 7.5 stimulating effect on biomass was observed by Ni²⁺+Fe²⁺+Mo⁶⁺. H₂ production was enhanced 2.7 fold particularly by Ni²⁺+Fe³⁺+Mo⁶⁺ at the late stationary growth phase. Whereas at pH 5.5 increased biomass was when Fe²⁺+Mo⁶⁺ or Mo⁶⁺ were added. H₂ yield was decreased compared with that at pH 6.5, but metal ions again enhanced it. During glucose fermentation at pH 6.5 biomass was increased by the mixtures of metal ions, and 1.2 fold increased H₂ yield was observed. At pH 7.5 Ni²⁺+Fe²⁺ increased biomass but Cu⁺ or Cu²⁺ had suppressing effect; Fe³⁺+Mo⁶⁺ stimulated H₂ production. At pH 5.5 biomass also was raised by Ni²⁺+Fe²⁺+Mo⁶⁺; H₂ yield was increased upon Mo⁶⁺ and Mo⁶⁺+Fe²⁺ or Mo⁶⁺+Fe³⁺ additions. The results point out the importance of Ni²⁺, Fe²⁺, Fe³⁺ and Mo⁶⁺ and some of their combinations for E. coli bacterial growth and H₂ production mostly during glycerol but not glucose fermentation and at acidic conditions (pH 5.5 and 6.5). They can be used for optimizing fermentation processes on glycerol, controlling bacterial biomass and developing H₂ production biotechnology.     

Simultaneous biohydrogen (H2) and bioplastic (poly-β-hydroxybutyrate-PHB) productions under dark,photo, and subsequent dark and photo fermentation utilizing various wastes

The present study is focused on bio hydrogen (H₂) and bioplastic (i.e., poly-β-hydroxybutyrate; PHB) productions utilizing various wastes under dark fermentation, photo fermentation and subsequent dark-photo fermentation. Potential bio H₂ and PHB producing microbes were enriched and isolated. The effects of substrate (rice husk hydrolysate, rice straw hydrolysate, dairy industry wastewater, and rice mill wastewater) concentration (10–100%) and pH (5.5–8.0) were examined in the batch mode under the dark and photo fermentation conditions. Using 100% rice straw hydrolysate at pH 7, the maximum bio H₂ (1.53 ± 0.04 mol H₂/mol glucose) and PHB (9.8 ± 0.14 g/L) were produced under dark fermentation condition by Bacillus cereus. In the subsequent dark-photo fermentation, the highest amounts of bio H₂ and PHB were recorded utilizing 100% rice straw hydrolysate (1.82 ± 0.01 mol H₂/mol glucose and 19.15 ± 0.25 g/L PHB) at a pH of 7.0 using Bacillus cereus (KR809374) and Rhodopseudomonas rutila. The subsequent dark-photo fermentative bio H₂ and PHB productions obtained using renewable biomass (i.e., rice husk hydrolysate and rice straw hydrolysate) can be considered with respect to the sustainable management of global energy sources and environmental issues.     

氧化还原电位控制的自絮凝酵母自动重复批次发酵

引言随着石油资源的日益减少和环境污染的逐渐加剧,使用可再生的清洁能源已经是世界各国的共识。在众多形式的非矿物质能源中,基于生物质的燃料乙醇已得到了广泛的应用[1]。但是,由于生产成本较高,各国的燃料乙醇生产大都依靠着政策扶植和税收优惠[2]。因此,看似十分"成熟"的乙醇生产产业,仍然需要进一步开发降低成本的创新技术[3]。近些年来,通过基因工程手段改造菌种[4]、     

曝气量对自热式高温好氧消化(ATAD)中试工艺运行的影响

设计了由两个圆罐串联的自热式高温好氧消化中试系统，处理城市污水污泥.采用批式试验，测试氧化还原电位（ORP），探讨曝气量对污泥稳定化处理效果的影响.试验发现，曝气量不能过高或过低，过高起到散热作用，使反应器自升温的温度下降，过低则影响微生物的活性，反应器的温度也低，两种情况都会造成挥发性悬浮固体（VSS）去除率降低.对于VSS浓度为46.6g/L的污泥，曝气量取0.6～1.0m^3/h较好，VSS的去除率可达到39.2%，趋于稳定化.通过测试ORP发现微氧环境有利于VSS的降解，提高VSS的去除率.在消化过程中反应器内ORP最低为-360mV，反应器中不仅有好氧菌，还存在厌氧菌和兼性菌。     

城市污水脱氮除磷SBR在线控制系统研究

SBR采用进水—厌氧—好氧—缺氧—好氧—沉淀—出水的运行方式处理城市污水。反应器装备有DO、ORP和pH等在线检测传感器。DO、ORP和pH变化的一些特征点可以用来判断和控制SBR中污水脱氮除磷过程的各个步骤。这包括:厌氧时,ORP和pH的转折点对应磷的释放;一次好氧时,DO、ORP的氨肘和pH的氨谷对应硝化结束;缺氧时,ORP的硝酸盐膝和pH的硝酸盐峰对应反硝化结束;二次好氧时,DO、ORP碳肘对应剩余碳的氧化结束,pH的转折点对应聚磷结束。控制系统能进行全自动运行来完成污水的脱氮除磷。     

在ORP中实现对J2ME库的支持

开放式运行平台(Open Runtime Platform,ORP)是一个高性能的MRTE(Managed Runtime Environment)软件，是用来研究动态编译和垃圾收集技术的开放资源研究平台。ORP是面向J2SE的运行平台，而在其之上运行的类库GNU Classpath与Java 1.2API规范完全兼容,J2ME是针对嵌入式设备及消费类电子产品的Java版本。该文将ORP进行了修改，使之能够获得SUN的连接的有限设备配置(Connected Limited Device Configuration,CLDC)库的支持，并能够运行简单的J2ME程序。