Name: construction and setup of a bench-scale algal photosynthetic bioreactor with temperature, light, and ph monitoring for kinetic growth tests
Uploaded: 2017-06-14T12:30:00.000+00:00
Duration: 10 min 8 s
Description: Watch this Scientific Journal Video about Construction and Setup of a Bench-scale Algal Photosynthetic Bioreactor with Temperature, Light, and pH Monitoring for Kinetic Growth Tests at JoVE.com

作者承认国家科学基金会研究与创新新兴前沿（第1332341号），用于资助这项研究。作者还要感谢Andrew Grieshop博士以及LabJack和DAQFactory在线支持社区在整个过程中提供的帮助和帮助。

<ol>
	<li>Liu, X., Clarens, A. F., Colosi, L. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Algae+biodiesel+has+potential+despite+inconclusive+results+to+date.">Algae biodiesel has potential despite inconclusive results to date.</a> Bioresour. Technol. 104, 803-806 (2012).</li><li>Chisti, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biodiesel+from+microalgae.">Biodiesel from microalgae.</a> Biotechnol. Adv. 25 (3), 294-306 (2007).</li><li>Lardon, L., H&#233;lias, A., Sialve, B., Steyer, J. -. P., Bernard, O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Life-cycle+assessment+of+biodiesel+production+from+microalgae.">Life-cycle assessment of biodiesel production from microalgae.</a> Environ. Sci. Technol. 43 (17), 6475-6481 (2009).</li><li>Henry, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experiments+on+the+Quantity+of+Gases+Absorbed+by+Water,+at+Different+Temperatures,+and+under+Different+Pressures.">Experiments on the Quantity of Gases Absorbed by Water, at Different Temperatures, and under Different Pressures.</a> Philos. Trans. R. Soc. London. 93 (1803), 29 (1803).</li><li>Wang, X., Hao, C., Zhang, F., Feng, C., Yang, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Inhibition+of+the+growth+of+two+blue-green+algae+species+(Microsystis+aruginosa+and+Anabaena+spiroides)+by+acidification+treatments+using+carbon+dioxide.">Inhibition of the growth of two blue-green algae species (Microsystis aruginosa and Anabaena spiroides) by acidification treatments using carbon dioxide.</a> Bioresour. Technol. 102 (10), 5742-5748 (2011).</li><li>Juneja, A., Ceballos, R. M., Murthy, G. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+Environmental+Factors+and+Nutrient+Availability+on+the+Biochemical+Composition+of+Algae+for+Biofuels+Production:+A+Review.">Effects of Environmental Factors and Nutrient Availability on the Biochemical Composition of Algae for Biofuels Production: A Review.</a> Energies. 6 (9), 4607-4638 (2013).</li><li>Bernard, O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hurdles+and+challenges+for+modelling+and+control+of+microalgae+for+CO+2+mitigation+and+biofuel+production.">Hurdles and challenges for modelling and control of microalgae for CO 2 mitigation and biofuel production.</a> J. Process Control. 21 (10), 1378-1389 (2011).</li><li>Guest, J. S., van Loosdrecht, M. C. M., Skerlos, S. J., Love, N. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lumped+Pathway+Metabolic+Model+of+Organic+Carbon+Accumulation+and+Mobilization+by+the+Alga+Chlamydomonas+reinhardtii.">Lumped Pathway Metabolic Model of Organic Carbon Accumulation and Mobilization by the Alga Chlamydomonas reinhardtii.</a> Environ. Sci. Technol. 47 (7), 3258-3267 (2013).</li><li>Packer, A., Li, Y., Andersen, T., Hu, Q., Kuang, Y., Sommerfeld, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Growth+and+neutral+lipid+synthesis+in+green+microalgae:+A+mathematical+model.">Growth and neutral lipid synthesis in green microalgae: A mathematical model.</a> Bioresour. Technol. 102 (1), 111-117 (2011).</li><li>Oren, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+hundred+years+of+Dunaliella+research:+1905-2005.">A hundred years of Dunaliella research: 1905-2005.</a> Saline Systems. 1, 2 (2005).</li></ol>

作者没有什么可以披露的。

该PBR系统提供监测和控制实验室规模的藻类动力学生长实验的能力，允许来自用于量化生长的实验测定的更多可重复的结果。然而，了解传感器测量的局限性和不确定性对于确保传感器读数准确反映反应器条件至关重要。这种理解包括与传感器相关的测量原理的基本知识，校准的过程和频率，测量不确定度以及传感器可以测量甚至不能测量的内容。例如，这里描述的光传感器的电响应不是均匀地分布在可见光谱范围内，并且可能需要将某些校正因子应用于传感器输出，这取决于如何分析该传感器数据。 温度水平和变化也是非常重要的，因为温度的变化可以大大的变化注意传感器响应。了解可能影响传感器读数的潜在干扰也至关重要;这种干扰可能是来自建筑物的环境电气噪声，或者可能来自测量环境（ 例如，钠离子可以大大影响pH值超过10的pH读数）。此外，将多个探针浸入溶液中，特别是高度离子和导电的盐溶液也是潜在的干扰源。测量pH（或离子强度，溶解氧，溶解的CO 2 等 ）的电极对环境电气噪声特别敏感，并且可以容易地扰动。用于保护电极信号的信号调理不能保证其他因素不会干扰探头读数。作为质量控制的一部分，应使用其他实验室设备，如手持式pH探针，手持光谱仪和温度计，以验证t他的传感器读数，并确保系统设置和运行正常。 必须解决的另一个限制是藻类和/或培养环境对传感器的可能影响。例如，如果藻类碎片或泡沫覆盖光传感器的光电二极管接收器，读数将受到影响。类似地，pH电极是非常敏感的，需要特别小心以确保准确的读数。这些电极通过测量由于H +离子的积聚而在内部连接处的电压差而起作用;需要探针内的水合缓冲层以保持精确的测量12 。取决于反应器内的条件，该层将会脱落，并且当探头浸没时，传感器的响应可能会在实验过程中发生变化。在初步测试中，在20天的实验过程中，pH电压输出没有漂移超过约0.2个pH单位，但应进行进一步评估，以表征传感器响应的这种变化，并建立最大的实验运行时间，特别是如果需要精细的pH调节/定量。 许多现有的用于分析藻类生长的实验室规模的PBR系统不会像需要一样严密地监控和控制内部文化环境，以确定不同因素如何影响藻类生长，因为以这种方式建立系统可能具有挑战性。该协议可以通过提供用于构建具有实时监控的PBR的分步说明来帮助实现更多的受控实验。此外，这种实时数据不仅可以用于更好地控制实验条件，而且可以用于估计生长动力学（ 例如，光密度读数作为一般生长速率的参考）。 受控的实验系统可以帮助藻类研究更加可重现。台秤PBR监测和控制的水蛭可以通过最小化实验设计中的非预期人为因素来提高实验效率，并有助于推动使藻类生物燃料成为可持续的替代燃料来源。

由于对全球气候变化和有限化石燃料资源的担忧日益增加，各国政府一直在制定减少化石燃料消费政策并鼓励开发新的可持续运输燃料。美国环境保护局制定了可再生能源燃料标准（RFS），要求到2022年，每年1400亿加仑的美国运输燃料组合中有36个来自可再生燃料。创新和转型技术将是必要的，以满足这些和未来可再生能源标准1 。 使用微藻类生物燃料具有帮助满足国家RFS同时减少温室气体排放的潜力2 。与基于陆地粮食作物的第一代生物燃料相比，微藻类生物燃料具有几个优点，如玉米和大豆。与第一代生物燃料不同，藻类b生物燃料消耗较少的土地，水和与食物有关的资源，因为藻类可以全年耕种，在荒地上使用盐水或废水。微藻与陆地作物相比具有较高的生长速率，可以积聚高水平的脂质，可以容易地转化为生物柴油3 。目前，由于由藻类培养，脂质分离和脂质精炼成生物柴油的能源密集型生产过程的高成本，不存在工业规模的藻类 - 生物燃料工厂。需要更多的研究来使这些过程更有效率和可持续性。 用于在人造环境中生产光营养微生物的光学透明封闭装置的PBR被认为是最有希望的培养方法之一3 。然而，目前的设计仍然缺乏使藻类对生物燃料生产过程所需的体积生产力ess更有效率和经济吸引力4 。强大的数学模型，考虑光照辐射和衰减，营养物质和二氧化碳的运输，以及微藻的生长可以极大地促进PBR设计和操作的优化。为了确定这些优化模型的物种特异性生长参数，需要进行大规模生长实验。 动力学测试需要仔细监测和控制实验装置，以防止意外的生长抑制剂。鉴于藻类的光合特性（ 即它们的二氧化碳消耗和光的吸收），维持受控条件在实验室规模的PBR中特别困难。如等式1所示 ，生长培养基中溶解的CO 2的量通常表示为<img alt="方程" src="/files/ftp_upload/55545/55545eq1.jpg" /> （ 等式2 ）将至少为a功能:1）CO 2分压和亨利均衡常数，这决定了溶解在溶液中的气体量（ 等式3 ）; 2）生长培养基的初始化学成分，影响碳酸根离子的形态和活性，pH值（ 等式4和5 ）。和3）温度，影响等式3-5 5 。 <img alt="方程" src="/files/ftp_upload/55545/55545eq2.jpg" /> <img alt="方程" src="/files/ftp_upload/55545/55545eq3.jpg" /> <img alt="方程" src="/files/ftp_upload/55545/55545eq4.jpg" /> <img alt="方程" src="/files/ftp_upload/55545/55545eq5.jpg" /> <img alt="方程" src="/files/ftp_upload/55545/55545eq6.jpg" />碳的各个阶段和化学形态对测量和维持PBR中溶解碳浓度一致性构成挑战保持其他条件不变（ 例如，随着藻类消耗CO 2 ，pH增加，并且增加溶解的CO 2底物可能导致抑制生长的酸性环境）。 在藻类动力学测试中控制条件的另外一层复杂性涉及PBR内的光强度。 PBR内的平均光强度不仅是入射光强度，还包括设计（ 如材料，形状，深度和混合），藻类生物量成分（特别是叶绿素）的吸光度，藻细胞的散射性质。随着藻类生长，平均光强度将会降低。光强度的这种变化，无论是由总细胞和生物量的增加，每个细胞的叶绿素含量的增加还是两者引起的，都可能最终诱导代谢反应，如叶绿素产量的增加细胞每个细胞或使用碳水化合物和脂质储存产品的能量7 。连续监测反应堆内的光强，提供了宝贵的信息。该数据有助于确保条件保持在指定范围内，如果与其他测量（ 即生物量，叶绿素浓度，反应器深度，入射光等 ）结合使用，可用于帮助估计藻类生长和吸光度参数。 了解藻类在指定条件下如何生长需要在实验室规模的动力学实验中监测pH，溶解的CO 2 ，光强度和温度。许多藻类生长设置没有装备来监测校准动力学模型所需的条件，使建模过程非常具有挑战性8 。虽然许多公司提供具有自动化和控制功能的台式PBR，但这些台式机e设置可能非常昂贵（约$ 20,000），并且可能不适应给定研究问题的所有实验考虑。 建立批量实验的控制反馈系统的第一步是实时数据采集。本文旨在演示如何构建和设置配备连续光，pH和温度监测的工作台式PBR。这种实时监控设置可以帮助确保实验条件保持在所需范围内，由研究者自行决定。尽管该协议没有详细说明具体的控制机制，但是这些分步指令为更高级的控制反馈可以实现所需的数据采集框架提供了基础。

<table><tbody><tr><td>Cast acrylic sheets</td><td>McMaster Carr</td><td>8560K244</td><td>7/8&#039;&#039; thick, 12 x 36&#039;&#039;, optically-clear, the size of sheets purchased will depend on reactor dimensions.</td></tr><tr><td>Acrylic cement</td><td>McMaster Carr</td><td>7517A4</td><td>Scigrip plastic pipe cement, #4SC nonwhitening for acrylic. Not needed if gaskets and screws are used for PBR assembly.</td></tr><tr><td>Acrylic cement applicator needle</td><td>McMaster Carr</td><td>75165A136</td><td>Acrylic cement applicator needle, 25 Gauge, 1&quot;, Stainless steel, PTFE lined.</td></tr><tr><td>Plastic dispensing bottle for acrylic cement</td><td>McMaster Carr</td><td>7544A67</td><td>Plastic dispensing bottle, 2-oz size, packs of 5.</td></tr><tr><td>Viscous acrylic cement</td><td>McMaster Carr</td><td>7515A11</td><td>Scigrip plastic pipe cement. Medium-bodied acrylic cement to seal in any gaps within PBR body.</td></tr><tr><td>PG-13.5 thread tap</td><td>McMaster Carr</td><td>2485A14</td><td>Can be used to help secure pH electrode to lid (if applicable).</td></tr><tr><td>PBR and lid</td><td>NCSU Precision Machine Shop</td><td>Karam Algae 3.2L Reactor Revision E</td><td>This machine shop is open to public for business. Contact shop manager.</td></tr><tr><td>pH sensor</td><td>Hamilton</td><td>238643</td><td>EasyFerm Plus 120, autoclavable, millivolt output.</td></tr><tr><td>Light sensor</td><td>Apogee Instruments</td><td>SQ-225</td><td>Amplified 0-5 volt electric calibration quantum sensor, water-proof.</td></tr><tr><td>Temperature sensor</td><td>LabJack</td><td>EI1034</td><td>Stainless steel, water-proof temperature sensor.</td></tr><tr><td>pH transmitter wire with BNC end</td><td>Sigma-Aldrich</td><td>HAM355173-1EA</td><td>This wire will vary with type of pH probe. Make sure wire is compatible with pH probe and has BNC connector end.</td></tr><tr><td>Unity gain pre-amplifier</td><td>Omega Engineering</td><td>PHTX-21</td><td>Signal processing amplifier for pH electrode needed for high-impedance pH readings.</td></tr><tr><td>Coaxial adapter, BNC female-to-binding post</td><td>Amazon</td><td>SMAKN B00NGD5K80</td><td>For connecting pH signal from pre-amplifier to microcontroller.</td></tr><tr><td>Capacitor (1000 uF)</td><td>Amazon</td><td>Nichicon BCBI4950</td><td>For low-pass filter.</td></tr><tr><td>Resistor (1000 ohm)</td><td>Radio Shack</td><td>2711321</td><td>For low-pass filter.</td></tr><tr><td>Hookup wire</td><td>RadioShack</td><td>2781222</td><td>For making low-pass filters, connecting sensors to microcontroller, and wiring motor.</td></tr><tr><td>Heat shrink tubing</td><td>RadioShack</td><td>2781611</td><td>For low-pass filter assembly.</td></tr><tr><td>Data acquisition and control unit</td><td>LabJack</td><td>LabJack U6</td><td>To process electrical signal from sensors and communicate with data acquisition and control software.</td></tr><tr><td>DAQFactory data acquisition software</td><td>DAQFactory</td><td>DAQFactory Express Release 5.87c Build: 2050</td><td>Free to download, for up to 10 channels.</td></tr><tr><td>Mini DC-gearmotor</td><td>McMaster Carr</td><td>6331K31</td><td>Motor for mixer impeller.</td></tr><tr><td>Impeller and shaft</td><td>N/A</td><td>N/A</td><td>Email authors for 3D files.</td></tr><tr><td>Variable DC power supply</td><td>Amazon</td><td>Tekpower HY1803D</td><td>Variable DC power supply, 0-18V @ 0-3A.</td></tr><tr><td>Grow Lamp</td><td>HydroGrow</td><td>SOL-1</td><td>This exact model is no longer available.</td></tr><tr><td>Incubator</td><td>Thermo Scientific</td><td>Precision Model 818</td><td>This particular incubator can withstand an internal heat source since this unit&#039;s cooling compressors run non-stop regardless of temperature setting.</td></tr></tbody></table>

construction and setup of a bench-scale algal photosynthetic bioreactor with temperature, light, and ph monitoring for kinetic growth tests

用于微藻培养的光合生物反应器（PBR）的最佳设计和操作对于改善微藻类生物燃料生产的环境和经济性能至关重要。在不同条件下估计微藻生长的模型有助于优化PBR设计和操作。为了有效，必须准确确定这些模型中使用的生长参数。藻类生长实验通常受到培养环境的动态性质的限制，需要控制系统来准确地确定动力学参数。实施受控批量实验的第一步是实时数据采集和监测。该协议概述了可用于进行微藻生长实验的台式光合生物反应器的装配和操作的过程。该协议描述了如何从亚克力尺寸和组装平板，台式规模的PBR。它还详细说明了如何配置使用数据采集和控制单元，模拟传感器和开源数据采集软件，连续进行pH，光和温度监测的PBR。

来自该实时监测系统的数据显示了台式PBR中藻类的动态培养环境，并突出了对系统进行监测和控制的需要。记录的温度数据（ 图6 ）显示了如何照明，孵化器空气温度和与藻类生长相关的能量耗散可以改变PBR内的温度，以及如何根据需要使用实时数据来调节孵化器温度控制。 在实验过程中测量的光进一步强调了这种不断增长的环境的动态性质。 如图7所示 ，作为光合光子通量密度（PPFD;μE-m -2 s -1 ）测量的光传感器读数在加入藻类之前为〜100PPFD，立即下降到85PPFD af接着用藻类培养物接种反应器。光照强度在第7天持续下降到5PPFD以下。光照强度的下降是由于生物量和细胞数量的增加，和/或增加叶绿素含量的吸收，表明藻类在第7天活跃，尽管低光照水平。需要额外的生物测量来进一步推断。 连续记录的pH数据显示，总体而言，使用实施的pH控制算法在该实验过程中充分控制pH值（ 图8 ）。这些数据显示了每分钟读数和小时平均值，显示了关于培养藻类和实时监控pH的几个关键点。首先，在用藻类接种PBR之后，pH增加到高于所需设定点7.6。预期这种变化，因为添加到PBR中的培养种子有apH值高于设定值，因为用于培养接种物的烧瓶不进行pH控制。其次，这个实时数据显示了pH电极对外部电气噪声的敏感程度。这种灵敏度由第1天和第2天之间的电极值急剧上升所引起。这些pH值的突然变化很可能是由来自相邻实验装置的电磁阀的电噪声引起的。这种电气干扰过早地触发了pH控制算法，以将CO 2注入到PBR中。因此，pH降低到所需的设定点以下。 pH电极的灵敏度可能导致极端的异常值，并且可能会破坏控制系统。 <img alt="图3" class="xfigimg" src="/files/ftp_upload/55545/55545fig3.jpg" /> 图3:pH响应和校准示例图。 （ a ）实施例的响应图e pH传感器（ b ）pH传感器的示例校准图，用于转换的方程式。回归分析显示95％置信区间。误差条不可见（标准误差小于0.03％）。这些图表显示pH传感器正确连接，其信号非常稳定。 <a href="http://ecsource.jove.com/files/ftp_upload/55545/55545fig3large.jpg" target="_blank">请点击此处查看此图的较大版本。</a> <img alt="图6" class="xfigimg" src="/files/ftp_upload/55545/55545fig6.jpg" /> 图6:7天实验期间PBR内的温度测量。深蓝色点表示传感器数据的1小时平均值，浅蓝色点表示在1分钟内获取的传感器读数（采集时间为1秒，平均长度为60），并使用制造商提供的转换因子转换为温度。黑色箭头<html>当调节培养箱温度设置以维持培养温度在25℃左右时（这个所需的设定点用红色，虚线表示）。温度波动是由于藻类生长和培养箱温度的变化。 <a href="http://ecsource.jove.com/files/ftp_upload/55545/55545fig6large.jpg" target="_blank">请点击此处查看此图的较大版本。</a> <img alt="图7" class="xfigimg" src="/files/ftp_upload/55545/55545fig7.jpg" /> 图7:7天实验期间PBR内的光测量。深蓝色点表示传感器数据的1小时平均值，浅蓝色点表示在1分钟内获取的传感器读数（采集时间为1秒，平均长度为60），并使用默认光传感器出厂校准值转换为PPFD。"&gt;请点击此处查看此图的较大版本。 <img alt="图8" class="xfigimg" src="/files/ftp_upload/55545/55545fig8.jpg" /> 图8:7天实验期间PBR内的pH测量。深蓝色点表示传感器数据的1小时平均值，浅蓝色点表示每1分钟记录的传感器读数（采集时间为0.1秒，平均长度为600），并使用通过校准建立的转换方程转换为pH。使用99％CO 2气体注入，将pH值保持在7.6至7.5之间。红色的虚线表示所需的pH范围。 <a href="http://ecsource.jove.com/files/ftp_upload/55545/55545fig8large.jpg" target="_blank">请点击此处查看此图的较大版本。</a>

Watch this Scientific Journal Video about Construction and Setup of a Bench-scale Algal Photosynthetic Bioreactor with Temperature, Light, and pH Monitoring for Kinetic Growth Tests at JoVE.com

Construction and Setup of a Bench-scale Algal Photosynthetic Bioreactor with Temperature, Light, and pH Monitoring for Kinetic Growth Tests

本文介绍了可以与其他方法一起使用的台式光合生物反应器的装配过程和操作，以估计相关的动力学生长参数。该系统使用传感器，数据采集和控制单元以及开源数据采集软件连续监控pH，光和温度。

用于动态生长测试的温度，光照和pH监测的台式藻类光合生物反应器的构建和设置

The optimal design and operation of photosynthetic bioreactors (PBRs) for microalgal cultivation is essential for improving the environmental and economic ...

construction-setup-bench-scale-algal-photosynthetic-bioreactor-with

Research

JoVE Journal

Bioengineering

16.2K 次观看.  North Carolina State University. 本文介绍了可以与其他方法一起使用的台式光合生物反应器的装配过程和操作，以估计相关的动力学生长参数。该系统使用传感器，数据采集和控制单元以及开源数据采集软件连续监控pH，光和温度。 

视频: Construction and Setup of a Bench-scale Algal Photosynthetic Bioreactor with Temperature, Light, and pH Monitoring for Kinetic Growth Tests

Optimize Flue Gas Settings to Promote Microalgae Growth in Photobioreactors via Computer Simulations

Flue gas from power plants can promote algal cultivation and reduce greenhouse gas emissions1. Microalgae not only capture solar energy more efficiently than plants3, but also synthesize advanced biofuels2-4. Generally, atmospheric CO2 is not a sufficient source for supporting maximal algal growth5. On the other hand, the high concentrations of CO2 in industrial exhaust gases have adverse effects on algal physiology. Consequently, both cultivation conditions (such as nutrients and light) and the control of the flue gas flow into the photo-bioreactors are important to develop an efficient &ldquo;flue gas to algae&rdquo; system. Researchers have proposed different photobioreactor configurations4,6 and cultivation strategies7,8 with flue gas. Here, we present a protocol that demonstrates how to use models to predict the microalgal growth in response to flue gas settings. We perform both experimental illustration and model simulations to determine the favorable conditions for algal growth with flue gas. We develop a Monod-based model coupled with mass transfer and light intensity equations to simulate the microalgal growth in a homogenous photo-bioreactor. The model simulation compares algal growth and flue gas consumptions under different flue-gas settings. The model illustrates: 1) how algal growth is influenced by different volumetric mass transfer coefficients of CO2; 2) how we can find optimal CO2 concentration for algal growth via the dynamic optimization approach (DOA); 3) how we can design a rectangular on-off flue gas pulse to promote algal biomass growth and to reduce the usage of flue gas. On the experimental side, we present a protocol for growing Chlorella under the flue gas (generated by natural gas combustion). The experimental results qualitatively validate the model predictions that the high frequency flue gas pulses can significantly improve algal cultivation.

Flue gas from power plants is a cheap CO2 source for algal growth. We have built prototype &#34;flue gas to algal cultivation&#34; systems and described how to scale up the algal cultivation process. We have demonstrated the use of a mass-transfer bio-reaction model to simulate and to design the optimal operation of flue gas for the growth of Chlorella sp. in algal photo-bioreactors.

优化烟气设置通过电脑模拟来促进微藻生长的光生物反应器中

Flue gas from power plants can promote algal cultivation and reduce greenhouse gas emissions1. Microalgae not only capture solar energy more efficiently ...

科研

环境科学

Quantification of Heavy Metals and Other Inorganic Contaminants on the Productivity of Microalgae

Increasing demand for renewable fuels has researchers investigating the feasibility of alternative feedstocks, such as microalgae. Inherent advantages include high potential yield, use of non-arable land and integration with waste streams. The nutrient requirements of a large-scale microalgae production system will require the coupling of cultivation systems with industrial waste resources, such as carbon dioxide from flue gas and nutrients from wastewater. Inorganic contaminants present in these wastes can potentially lead to bioaccumulation in microalgal biomass negatively impact productivity and limiting end use. This study focuses on the experimental evaluation of the impact and the fate of 14 inorganic contaminants (As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, Sb, Se, Sn, V and Zn) on Nannochloropsis salina growth. Microalgae were cultivated in photobioreactors illuminated at 984 &#181;mol m-2 sec-1 and maintained at pH 7 in a growth media polluted with inorganic contaminants at levels expected based on the composition found in commercial coal flue gas systems. Contaminants present in the biomass and the medium at the end of a 7 day growth period were analytically quantified through cold vapor atomic absorption spectrometry for Hg and through inductively coupled plasma mass spectrometry for As, Cd, Co, Cr, Cu, Mn, Ni, Pb, Sb, Se, Sn, V and Zn. Results show N. salina is a sensitive strain to the multi-metal environment with a statistical decrease in biomass yieldwith the introduction of these contaminants. The techniques presented here are adequate for quantifying algal growth and determining the fate of inorganic contaminants.

Integration of microalgal cultivation with industrial flue gas will ultimately introduce heavy metals and other inorganic compounds into the growth media. This study presents a procedure used to determine the end fate and impact of heavy metals and inorganic contaminants on the growth of Nannochloropsis salina grown in photobioreactors.

重金属和微藻的产其他无机污染物的量化

Increasing demand for renewable fuels has researchers investigating the feasibility of alternative feedstocks, such as microalgae. Inherent advantages ...

Comparison of Scale in a Photosynthetic Reactor System for Algal Remediation of Wastewater

An experimental methodology is presented to compare the performance of two different sized reactors designed for wastewater treatment. In this study, ammonia removal, nitrogen removal and algal growth are compared over an 8-week period in paired sets of small (100 L) and large (1,000 L) reactors designed for algal remediation of landfill wastewater. Contents of the small and large scale reactors were mixed before the beginning of each weekly testing interval to maintain equivalent initial conditions across the two scales. System characteristics, including surface area to volume ratio, retention time, biomass density, and wastewater feed concentrations, can be adjusted to better equalize conditions occurring at both scales. During the short 8-week representative time period, starting ammonia and total nitrogen concentrations ranged from 3.1-14 mg NH3-N/L, and 8.1-20.1 mg N/L, respectively. The performance of the treatment system was evaluated based on its ability to remove ammonia and total nitrogen and to produce algal biomass. Mean &#177; standard deviation of ammonia removal, total nitrogen removal and biomass growth rates were 0.95&#177;0.3 mg NH3-N/L/day, 0.89&#177;0.3 mg N/L/day, and 0.02&#177;0.03 g biomass/L/day, respectively. All vessels showed a positive relationship between the initial ammonia concentration and ammonia removal rate (R2=0.76). Comparison of process efficiencies and production values measured in reactors of different scale may be useful in determining if lab-scale experimental data is appropriate for prediction of commercial-scale production values.

An experimental methodology is presented to compare the performance of small (100 L) and large (1,000 L) scale reactors designed for algae remediation of landfill wastewater. System characteristics, including surface area to volume ratio, retention time, biomass density, and wastewater feed concentrations, can be adjusted based on application.

规模在光合反应器系统对污水的整治藻类比较

An experimental methodology is presented to compare the performance of two different sized reactors designed for wastewater treatment. In this study, ...

Operation of a Benchtop Bioreactor

Fermentation systems are used to provide an optimal growth environment for many different types of cell cultures. The ability afforded by fermentors to carefully control temperature, pH, and dissolved oxygen concentrations in particular makes them essential to efficient large scale growth and expression of fermentation products. This video will briefly describe the advantages of the fermentor over the shake flask. It will also identify key components of a typical benchtop fermentation system and give basic instruction on setup of the vessel and calibration of its probes. The viewer will be familiarized with the sterilization process and shown how to inoculate the growth medium in the vessel with culture. Basic concepts of operation, sampling, and harvesting will also be demonstrated. Simple data analysis and system cleanup will also be discussed.

Fermentors are used to increase culture yield and productivity of bioengineered cells. After screening multiple microbial or animal cell culture candidates in shake flasks, the next logical step is to increase the selected culture&#x2019;s biomass with the fermentor. This video demonstrates the setup and operation of a typical benchtop bioreactor system.

一个台式生物反应器的操作

Fermentation systems are used to provide an optimal growth environment for many different types of cell cultures. The ability afforded by fermentors to ...

生物工程

Cultivation of Green Microalgae in Bubble Column Photobioreactors and an Assay for Neutral Lipids

There is significant interest in the study of microalgae for engineering applications such as the production of biofuels, high value products, and for the treatment of wastes. As most new research efforts begin at laboratory scale, there is a need for cost-effective methods for culturing microalgae in a reproducible manner. Here, we communicate an effective approach to culture microalgae in laboratory-scale photobioreactors, and to measure the growth and neutral lipid content of that algae. Instructions are also included on how to set up the photobioreactor system. Although the example organisms are species of Chlorella and Auxenochlorella, this system can be adapted to cultivate a wide range of microalgae, including co-cultures of algae with non-algae species. Stock cultures are first grown in bottles to produce inoculum for the photobioreactor system. Algae inoculum is concentrated and transferred to photobioreactors for cultivation in batch mode. Samples are collected daily for the optical density readings. At the end of the batch culture, cells are harvested by centrifuge, washed, and freeze dried to obtain a final dry weight concentration. The final dry weight concentration is used to create a correlation between the optical density and the dry weight concentration. A modified Folch method is subsequently used to extract total lipids from the freeze-dried biomass and the extract is assayed for its neutral lipid content using a microplate assay. This assay has been published previously but protocol steps were included here to highlight critical steps in the procedure where errors frequently occur. The bioreactor system described here fills a niche between simple flask cultivation and fully-controlled commercial bioreactors. Even with only 3-4 biological replicates per treatment, our approach to culturing algae leads to tight standard deviations in the growth and lipid assays.

Here, we present a protocol to construct lab-scale bubble column photobioreactors and use them to culture microalgae. It also provides a method for the determination of the culture growth rate and neutral lipid content.

气泡柱光生物反应器中绿色微藻的培养及中性脂质的测定

There is significant interest in the study of microalgae for engineering applications such as the production of biofuels, high value products, and for the ...

Microalgae Cultivation and Biomass Quantification in a Bench-Scale Photobioreactor with Corrosive Flue Gases

Photobioreactors are illuminated cultivation systems for experiments on phototrophic microorganisms. These systems provide a sterile environment for microalgal cultivation with temperature, pH, and gas composition and flow rate control. At bench-scale, photobioreactors are advantageous to researchers studying microalgal properties, productivity, and growth optimization. At industrial scales, photobioreactors can maintain product purity and improve production efficiency. The video describes the preparation and use of a bench-scale photobioreactor for microalgal cultivation, including the safe use of corrosive gas inputs, and details relevant biomass measurements and biomass productivity calculations. Specifically, the video illustrates microalgal culture storage and preparation for inoculation, photobioreactor assembly and sterilization, biomass concentration measurements, and a logistic model for microalgal biomass productivity with rate calculations including maximum and overall biomass productivities. Additionally, since there is growing interest in experiments to cultivate microalgae using simulated or real waste gas emissions, the video will cover the photobioreactor equipment adaptations necessary to work with corrosive gases and discuss safe sampling in such scenarios.

Bench-scale, axenic cultivation facilitates microalgal characterization and productivity optimization before subsequent process scale-up. Photobioreactors provide the necessary control for reliable and reproducible microalgal experiments and can be adapted to safely cultivate microalgae with the corrosive gases (CO2, SO2, NO2) from municipal or industrial combustion emissions.

具有腐蚀性烟气的台式光生物反应器中的微藻培养和生物量定量

Photobioreactors are illuminated cultivation systems for experiments on phototrophic microorganisms. These systems provide a sterile environment for ...

Coupling Carbon Capture from a Power Plant with Semi-automated Open Raceway Ponds for Microalgae Cultivation

In the United States, 35% of the total carbon dioxide (CO2) emissions come from the electrical power industry, of which 30% represent natural gas electricity generation. Microalgae can biofix CO2 10 to 15 times faster than plants and convert algal biomass to products of interest, such as biofuels. Thus, this study presents a protocol that demonstrates the potential synergies of microalgae cultivation with a natural gas power plant situated in the southwestern United States in a hot semi-arid climate. State-of-the-art technologies are used to enhance carbon capture and utilization via the green algal species Chlorella sorokiniana, which can be further processed into biofuel. We describe a protocol involving a semi-automated open raceway pond and discuss the results of its performance when it was tested at the Tucson Electric Power plant, in Tucson, Arizona. Flue gas was used as the main carbon source to control pH, and Chlorella sorokiniana was cultivated. An optimized medium was used to grow the algae. The amount of CO2 added to the system as a function of time was closely monitored. Additionally, other physicochemical factors affecting algal growth rate, biomass productivity, and carbon fixation were monitored, including optical density, dissolved oxygen (DO), electroconductivity (EC), and air and pond temperatures. The results indicate that a microalgae yield of up to 0.385 g/L ash-free dry weight is attainable, with a lipid content of 24%. Leveraging synergistic opportunities between CO2 emitters and algal farmers can provide the resources required to increase carbon capture while supporting the sustainable production of algal biofuels and bioproducts.

A protocol is described to utilize the carbon dioxide in natural gas power plant flue gas to cultivate microalgae in open raceway ponds. Flue gas injection is controlled with a pH sensor, and microalgae growth is monitored with real time measurements of optical density.

将发电厂的碳捕获与半自动开放式管道池相结合，用于微藻养殖

In the United States, 35% of the total carbon dioxide (CO2) emissions come from the electrical power industry, of which 30% represent natural gas ...

用于从猪废沼气中获取生物甲烷的微藻培养

Biogas Purification through the use of a Microalgae-Bacterial System in Semi-Industrial High Rate Algal Ponds

In recent years, a number of technologies have emerged to purify biogas into biomethane. This purification entails a reduction in the concentration of polluting gases such as carbon dioxide and hydrogen sulfide to increase the content of methane. In this study, we used a microalgal cultivation technology to treat and purify biogas produced from organic waste from the swine industry to obtain ready-to-use biomethane. For cultivation and purification, two 22.2 m3 open-pond photobioreactors coupled with an absorption-desorption column system were set up in San Juan de los Lagos, Mexico. Several recirculation liquid/biogas ratios (L/G) were tested to obtain the highest removal efficiencies; other parameters, such as pH, dissolved oxygen (DO), temperature, and biomass growth, were measured. The most efficient L/Gs were 1.6 and 2.5, resulting in a treated biogas effluent with a composition of 6.8%vol and 6.6%vol in CO2, respectively, and removal efficiencies for H2S up to 98.9%, as well as maintaining O2 contamination values of less than 2%vol. We found that pH greatly determines CO2 removal, more so than L/G, during cultivation because of its participation in the photosynthetic process of microalgae and its ability to vary pH when solubilized due to its acidic nature. DO, and temperature oscillated as expected from the light-dark natural cycles of photosynthesis and the time of day, respectively. Biomass growth varied with CO2 and nutrient feeding as well as reactor harvesting; however, the trend remained primed for growth.

作者聚焦:扩展微藻生物技术以提高生物甲烷产量 

Air pollution impacts the quality of life of all organisms. Here, we describe the use of microalgae biotechnology for the treatment of biogas (simultaneous removal of carbon dioxide and hydrogen sulfide) and the production of biomethane through semi-industrial open high-rate algal ponds and subsequent analysis of treatment efficiency, pH, dissolved oxygen, and microalgae growth.

在半工业化高速率藻类池塘中使用微藻细菌系统进行沼气净化

In recent years, a number of technologies have emerged to purify biogas into biomethane. This purification entails a reduction in the concentration of ...

用于动态生长测试的温度，光照和pH监测的台式藻类光合生物反应器的构建和设置

摘要

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此视频中的章节

优化烟气设置通过电脑模拟来促进微藻生长的光生物反应器中

重金属和微藻的产其他无机污染物的量化

规模在光合反应器系统对污水的整治藻类比较

一个台式生物反应器的操作

气泡柱光生物反应器中绿色微藻的培养及中性脂质的测定

具有腐蚀性烟气的台式光生物反应器中的微藻培养和生物量定量

将发电厂的碳捕获与半自动开放式管道池相结合，用于微藻养殖

在半工业化高速率藻类池塘中使用微藻细菌系统进行沼气净化

在半工业化高速率藻类池塘中使用微藻细菌系统进行沼气净化

在半工业化高速率藻类池塘中使用微藻细菌系统进行沼气净化