这项工作得到了美国能源部DE-EE0006269区域藻类原料试验台项目的支持。我们还感谢Esteban Jimenez，Jessica Peebles，Francisco Acedo，Jose Cisneros，RAFT Team，Mark Mansfield，UA发电厂工作人员和TEP发电厂工作人员的所有帮助。

1.生长系统:室外开放式水道池塘设置
<ol><li>在靠近烟气源（含有8-10%CO2）的地方设置开放式水道池。确保池塘反应器位置有水和电，并且反应器在一天中的大部分时间里不在阴凉处（图1）。</li>
	<li>在燃烧后过程中，使用0.95厘米的燃油软管捕获烟气，在烟气进入烟囱排放到大气中之前几米处（图2）。</li>
	<li>使用20 L水收集器和烟囱和压缩机之间的冷凝器（盘管长度〜12 m）从烟气中除水（图2）。 注:烟气通常含有约 9\u201213.8% 的水28。此外，冷凝器和管道冷却烟气16。</li>
	<li>将以下传感器连接到数据记录器以监测藻类生长:（1）实时光密度传感器29，其测量两个波长（650和750nm）的吸光度，并且可以检测最大藻类细胞浓度1.05 g / L;（2）溶解氧传感器;（3）空气和池塘热电偶;（4）pH传感器;（5）EC传感器。 注:此外，pH 和 EC 传感器连接到变送器。数据记录器单元配置如图 3所示。</li>
	<li>确保藻类生长系统的所有组件在接种前都经过校准并正常工作。</li>
</ol>2.pH控制系统
<ol><li>使用压缩机、控制阀系统和数据记录程序管理烟气喷射，如图 2 和 图3 （补充材料A）所示。</li>
	<li>使用管子通过石材扩散器将烟气从控制阀引导到滚道池的底部。</li>
	<li>根据pH值将烟气注入生长系统。当pH值大于8.05时，系统将注入烟气，而当pH值小于8.00时，系统将在无生长期间停止烟气注入。流量以标准升/分钟（SLPM）为单位进行测量。 注:在控制阀中，入口烟气压力限制为最大50 psi。</li>
</ol>3. 藻类选择和菌株维持（光照和温度）
注:绿藻小球藻DOE 1412由Juergen Polle（布鲁克林学院）30，31分离，并由国家先进生物燃料和生物制品联盟（NAABB）选择;其选择基于Huesemann等人先前进行的菌株表征研究。他们对西南地区使用室外开放式水道池塘时的藻类筛选，生物量生产力和气候模拟培养（例如，温度和光照）的研究为本项目中使用的方法提供了信息。
<ol><li>使用12小时/ 12小时光/暗循环在室温（25°C）下保持培养物。</li>
	<li>将光强度保持在200μM/ m2 / s，以维持在平板和小液体培养物（50 mL至500 mL）中生长的培养物。</li>
	<li>在 50 mL 至 500 mL 的液体培养物中，以 400 μM/m 2/s 的速度，在 5 L 至20 L 的液体培养物中，在 600\u200μM/m 2/s 下保持轻强度以增大。</li>
</ol>4. 放大和质量控制
<ol><li>使用去离子水和以下盐制备BG11培养基，用于常量营养素，g / L:1.5 NaNO3，0.04 K2HPO4，0.075 MgSO4 * H2O，0.036 CaCl2 * H2O，0.006（NH4）5Fe（C6H4O7）2，0.006 Na2EDTA * 2 H， 0.02 Na2CO3;加入1 mL/L微量元素溶液，其中含有以下微量营养素:2.86 H3BO3，1.81 MnCl2 *4H2O，0.22 ZnSO4 * 7H2O，0.39 Na2MoO4 * 2H2O，0.079 CuSO4 * 5H2O，0.0494 Co（NO3）2 * 6H2O。 注意:对于平板接种和/或长期储存，加入7.5克/ L巴斯托琼脂;对于培养接种，不需要添加琼脂。在高压釜中在121°C下灭菌培养基21分钟。</li>
	<li>将BG11培养基与琼脂一起倒入无菌层流罩或生物安全柜中的培养皿中。一旦板变硬并冷却，从重新悬浮的冷冻藻类储备培养物中移液500μL，并加入氨苄西林（100μg/ mL）;将藻类板在摇摇杯（120rpm）中孵育1至2周。</li>
	<li>使用无菌环从培养板中选择单个藻类菌落，并将其接种在含有无菌生长培养基的50mL管中，放在干净的生物安全柜中。在摇床（120rpm）上生长小液体培养物一周。</li>
	<li>将50mL藻类培养物（线性生长阶段，OD750nm ≥1）转移到具有500mL液体培养基的1L烧瓶中。用橡胶塞和不锈钢管安装每个烧瓶以提供曝气。使用0.2μm空气杀菌过滤器过滤空气。让培养物生长一到两周。使用分光光度计（OD750nm）监测细胞密度。</li>
	<li>将500mL液体培养物放入含有8L非无菌培养基的10L卡托中，并注入5%CO2 和95%空气的混合物。然后，在与步骤4.4相同的条件下培养藻类。</li>
	<li>每周监测一次储备板和液体培养物（在步骤 4.2\u20124.5 中）。取等分试样并在显微镜下以10倍和40倍放大倍率观察，以确保所需菌株的生长。保留培养物，直到它们被破坏或用于实验。丢弃受污染的培养物。</li>
</ol>5. 开放池塘养殖用浓缩培养基制备
<ol><li>为了制备微量元素溶液，用蒸馏水（DW）部分填充1L容量瓶。插入磁力搅拌棒，并依次加入 表1 所示的化学品。确保每种成分在添加下一种成分之前溶解。取下磁铁并将烧瓶填充到1 L体积标记。</li>
	<li>用DW部分填充1 L玻璃瓶，然后插入磁力搅拌棒。将容器放在磁力搅拌器板的顶部，并添加反应器最终体积的化学物质，按顺序添加，确保每个化学物质完全溶解。 表2 列出了制备1L培养基的化学品，因此将所有值乘以反应器的最终体积。将玻璃瓶填充至1 L。</li>
</ol>6. 室外开放式水道池接种
<ol><li>在每次接种前和收获后使用30%漂白剂彻底清洁反应器。建议将漂白剂放置过夜。冲洗反应器以除去所有漂白剂。</li>
	<li>在藻类接种之前，根据其相应的校准程序校准所有传感器。</li>
	<li>使用水源稀释浓缩的介质（在步骤5中），将滚道池填充至80%。</li>
	<li>使用充满藻类的10L carboy（线性生长期OD750nm > 2）接种反应器，并使其达到最终体积。</li>
	<li>一旦指数阶段过去，通过用木托盘部分遮蔽水道池塘约3天（图4），作为避免光抑制的适应策略，使微藻适应。 注:这段时间还将为微藻适应烟气直喷引起的应力提供时间。</li>
</ol>7. 发电站批量生长实验
<ol><li>检查并记录任何日常变化，包括水分蒸发、明轮电机、传感器功能以及任何异常情况。</li>
	<li>每天排空并检查压缩机和疏水阀，以除去任何多余的水，以尽量减少腐蚀，因为烟气具有高度腐蚀性34。</li>
	<li>将数据记录仪配置为每 10 秒扫描一次每个传感器测量值，并每 10 分钟存储一次平均数据。这些包括溶解氧、pH、EC、实时光密度以及空气和反应器温度。</li>
</ol>8. 离散采样和监测
<ol><li>确保水位在反应堆的最终体积处保持恒定，否则光密度测量将受到影响。</li>
	<li>补充反应器中的水后，使用紫外可见分光光度计通过光密度（540，680和750nm）取5mL样品进行细胞质量测量。每天重复该过程。</li>
	<li>每周采集 500 mL 样品三次，用于显微镜观察和基于无灰干重 （AFDW） 的生物质浓度。<ol>
<li>使用10倍和40倍物镜进行显微镜观察。此外，这些显微镜放大倍率被用作步骤4.6中描述的藻类质量控制的一部分。</li>
		<li>在步骤8.3中使用400 mL样品进行AFDW<ol>
<li>将每个0.7μm孔径的玻璃超细纤维过滤器置于铝箔托盘中，并使用熔炉在540°C下预处理每个铝箔托盘/过滤器4小时。</li>
			<li>使用#2铅笔标记每个铝箔托盘，记录其重量（A），并将其放入真空过滤设备中。</li>
			<li>在测量出要过滤的体积之前，用力搅拌藻类样品。过滤足够的藻类样品，得到8至16mg之间的前/后灰分重量差。选择要在整个实验过程中使用的权重差，并保持此值不变。</li>
			<li>将含有藻类样品的每个过滤器置于105°C的烘箱中的铝箔托盘中至少12小时。</li>
			<li>从干燥炉中取出铝箔托盘/过滤器，并将其放入玻璃干燥器中以防止吸水。记录每个铝箔托盘/过滤器重量（B）。</li>
			<li>将铝箔托盘/过滤器置于540°C马弗炉中4小时。</li>
			<li>关闭马弗炉，冷却铝箔托盘/过滤器，将它们放入干燥器中，并记录每个箔托盘/过滤器重量（C）。</li>
			<li>使用重量分析计算 AFDW: % AFDW= C – A x 100 / B</li>
		</ol>
</li>
	</ol>
</li>
	<li>在收获前保持2 L藻类，使用溶剂进行微波辅助提取（MAE）脂质提取分析。<ol>
<li>以4，400×g 的相对离心力（RFC）离心藻类样品15分钟。取藻类沉淀，用烤箱在80°C下干燥至少24小时。</li>
		<li>研磨藻类样品并称量藻类粉末（推荐的生物质范围为0.3g至0.5g）。</li>
		<li>将藻粉（干藻类生物质）加入微波加速反应系统（MARS）Xpress容器中，在罩下加入10mL氯仿:甲醇（2:1，v / v）溶剂溶液，关闭容器，静置过夜。</li>
		<li>使用溶剂传感器将容器放入MARS机器中，在70°C和800 W功率下60分钟。</li>
		<li>将船只带出火星，让它们在引擎盖下冷却。</li>
		<li>使用漏斗和玻璃棉将每个液体样品转移到预先称重的玻璃试管中，分离含有氯仿，甲醇和脂质的液体部分，并保持固体（生物质不含脂质）以进行其他分析。</li>
		<li>将含有脂质的试管取到氮气蒸发器中，一旦液体蒸发，将其取出，然后将试管在引擎盖下过夜，以确保完全干燥。</li>
		<li>使用重量法分析计算脂质含量（重量百分比）: 脂质含量（重量百分比）=脂质干生物量×100/干藻质量</li>
	</ol>
</li>
</ol>9. 藻类收获和作物轮作
<ol><li>当培养接近达到固定阶段时，收获总藻类培养量的75%。取 2\u20125 L 培养物，在实验室中进行生物质生产力分析。处理并将其余的藻类转化为所需的藻类产品。</li>
	<li>通过使用剩余的25%藻类作为接种物来重新生长开放的水道池塘。加入高达反应器总体积80%的水，加入浓缩的介质，然后完成填充，直到反应器的最终体积（如有必要）。</li>
	<li>根据季节，根据温度和光照强度条件培养适当的藻类品系。</li>
</ol>10. 数据管理
<ol><li>在数据记录器中记录数据并收集以进行分析，如步骤7.3所示。</li>
	<li>考虑将原始和分析数据保存在区域藻类原料测试平台 （RAFT） 共享驱动器中。RAFT项目合作者贡献他们的数据来模拟和建模藻类生产力并验证户外栽培。</li>
</ol>

作者没有什么可透露的。

在这项研究中，我们证明了在炎热的半干旱气候下，协同耦合烟气碳捕获和微藻培养是可能的。半自动水道池塘系统的实验方案集成了最先进的技术，以实时监测使用烟气作为碳源时与藻类生长相关的相关参数。拟议的议定书旨在减少藻类养殖的不确定性，这是20，21，36水道池塘的主要缺点之一。根据我们的经验，该协议最关...

全球变暖是当今世界面临的最重要的环境问题之一1.研究表明，主要原因是由于人类活动导致大气中温室气体（GHG）排放量的增加，主要是CO2，2，3，4，5，6，7。在美国，二氧化碳排放密度最大的主要来自能源部门的化石燃料燃烧，特别是发电厂3，7，8，9。因此，碳捕集和利用（CCU）技术已成为减少温室气体排放的主要战略之一2，7，10。这些包括利用阳光在营养物质存在下通过光合作用将CO2和水转化为生物质的生物系统。由于生长速度快，CO2固定能力高，生产能力高，提出了使用微藻的方法。此外，微藻具有广泛的生物能源潜力，因为生物质可以转化为感兴趣的产品，例如可以取代化石燃料的生物燃料7，9，10，11，12。
微藻可以在各种养殖系统或反应器中生长并实现生物转化，包括开放式水道池塘和封闭式光生物反应器13、14、15、16、17、18、19。研究人员研究了在室内或室外条件下决定两种栽培系统中生物过程成功与否的优点和局限性5，6，16，20，21，22，23，24，25.开放式水道池塘是烟气直接从烟囱中分配的情况下，最常见的碳捕获和利用养殖系统。这种类型的栽培系统相对便宜，易于放大，能源成本低，混合能源要求低。此外，这些系统可以很容易地与发电厂位于同一地点，以使CCU过程更加高效。但是，需要考虑一些缺点，例如CO2气体/液体传质的限制。虽然存在局限性，但开放式水道池塘已被提议为最适合室外微藻生物燃料生产的系统5，9，11，16，20。
在本文中，我们详细介绍了在开放式水道池塘中培养微藻的方法，该方法结合了从天然气发电厂烟气中捕获的碳。该方法由一个半自动化系统组成，该系统根据培养pH值控制烟气注入;该系统使用光密度、溶解氧 （DO）、电导率 （EC） 以及空气和池塘温度传感器实时监测和记录 小球藻 培养状态。在图森电力设施中，数据记录仪每10分钟收集一次藻类生物质和烟气注入数据。藻类菌株维持、放大、质量控制测量和生物质表征（例如，光密度、g/L 和脂质含量之间的相关性）在亚利桑那大学的实验室环境中进行。先前的协议概述了一种优化烟气设置的方法，以通过计算机模拟26促进光生物反应器中的微藻生长。这里介绍的协议是独一无二的，因为它利用了开放式水道池塘，并且设计用于在天然气发电厂现场实施，以便直接利用产生的烟气。此外，实时光密度测量是协议的一部分。所描述的系统针对炎热的半干旱气候（柯本BSh）进行了优化，该气候的降水量低，降水逐年变化很大，相对湿度低，蒸发率高，天空晴朗，太阳辐射强烈27.

<table><tbody><tr><td>Adjustable speed motor (paddle wheel system)</td><td>Leeson</td><td>174307</td><td>Lesson 174307.00, type: SCR Voltage; Amps:10</td></tr><tr><td>Aluminum weight boats</td><td>Fisher Scientific</td><td>08-732-102</td><td>Fisherbrand Aluminum Weighing Dishes</td></tr><tr><td>Ammonium Iron (III) (NH?)?[Fe(C?H?O?)?]</td><td>Fisher Scientific</td><td>1185 - 57 - 5</td><td>Medium preparation. Ammonium iron(III) citrate</td></tr><tr><td>Ammonium Phosphate</td><td>Sigma-Aldrich</td><td>7722-76-1</td><td>This chemical is used for the optimized medium</td></tr><tr><td>Ampicillin sodium salt</td><td>Sigma Aldrich</td><td>A9518-5G</td><td>This chemical is used for avoiding algae contamination</td></tr><tr><td>Autoclave</td><td>Amerex Instrument Inc</td><td></td><td>Hirayama HA300MII</td></tr><tr><td>Bacto agar</td><td>Fisher Scientific</td><td>BP1423500</td><td>Fisher BioReagents Granulated Agar</td></tr><tr><td>Bleach</td><td>Clorox</td><td></td><td>Germicidal Bleach, concentrated clorox</td></tr><tr><td>Boric Acid (H3BO3)</td><td>Fisher Scientific</td><td>10043-35-3</td><td>Trace Elelements: Boric acid</td></tr><tr><td>Calcium chloride dihydrate (CaCl2*2H2O)</td><td>Sigma-Aldrich</td><td>10035-04-8</td><td>Medium preparation. Calcium chloride dihydrate</td></tr><tr><td>Carboys (20 L)</td><td>Nalgene - Thermo Fisher Scientific</td><td>2250-0050PK</td><td>Polypropylene Carboy w/Handles</td></tr><tr><td>Centrifuge</td><td>Beckman Coulter, Inc</td><td></td><td>J2-21</td></tr><tr><td>Chloroform</td><td>Sigma-Aldrich</td><td>67-66-3</td><td>This chemical is used for lipid extraction</td></tr><tr><td>Citraplex 20% Iron</td><td>Loveland Products</td><td>SDS No. 1000595582 -17-LPI</td><td>https://www.fbn.com/direct/product/Citraplex-20-Iron#product_info</td></tr><tr><td>Cobalt (II) nitrate hexahydrate (Co(NO3)2*6H2O)</td><td>Sigma-Aldrich</td><td>10026-22-9</td><td>Trace Elements: Cobalt (II) nitrate hexahydrate</td></tr><tr><td>Compressor</td><td>Makita</td><td>MAC700</td><td>This equipment is used for the injection CO2 system</td></tr><tr><td>Control Valve</td><td>Sierra Instruments</td><td>SmartTrak 100</td><td>This item needs to be customized for your application. In our case, it was used a 5% CO2 and 95% air mixture.</td></tr><tr><td>Copper (II) Sulfate Pentahydrate (CuSO4*5H2O)</td><td>Sigma-Aldrich</td><td>7758-99-8</td><td>Trace Elements: Copper (II) Sulfate Pentahydrate</td></tr><tr><td>Data Logger: Campbell unit CR3000</td><td>Scientific Campbell</td><td>CR3000</td><td>This equipment is used for controlling all the system, motoring and recording data</td></tr><tr><td>Dissolvde Oxygen Solution</td><td>Campbell Scientific</td><td>14055</td><td>Dissolved oxygen electrolyte solution DO6002 - Lot No. 211085</td></tr><tr><td>Dissolved Oxygen probe</td><td>Sensorex</td><td>?</td><td>DO6400/T Dissolved Oxygen Sensor with Digital Communication</td></tr><tr><td>Electroconductivity calibration solution</td><td>Ricca Chemical Company</td><td>2245 - 32 ( R2245000-1A )</td><td>Conductivity Standard, 5000 uS/cm at 25C (2620 ppm TDS as NaCl)</td></tr><tr><td>Electroconductivity probe sensor</td><td>Hanna Instruments</td><td>HI3003/D</td><td>Flow-thru Conductivity Probe - NTC Sensor, DIN Connector, 3m Cable</td></tr><tr><td>Ethylenediaminetetraacetic acid disodium salt dihydrate (Na2EDTA*2H2O)</td><td>Sigma-Aldrich</td><td>6381-92-6</td><td>Medium Preparation: Ethylenediaminetetraacetic acid disodium salt dihydrate</td></tr><tr><td>Filters</td><td>Fisher Scientific</td><td>09-874-48</td><td>Whatman Binder-Free Glass Microfiber Filters</td></tr><tr><td>Flasks</td><td>Fisher scientific</td><td>09-552-40</td><td>Pyrex Fernbach Flasks</td></tr><tr><td>Furnace</td><td>Hogentogler</td><td>Model: F6020C-80</td><td>Thermo Sicentific Thermolyne F6020C - 80 Muffle Furnace</td></tr><tr><td>Glass dessicator</td><td>VWR International LLC</td><td>75871-430</td><td>Type 150, 140 mm of diameter</td></tr><tr><td>Glass funnel</td><td>Fisher Scientific</td><td>FB6005865</td><td>Fisherbrand Reusable Glass Long-Stem Funnels</td></tr><tr><td>Laminar flow hood</td><td>Fisher Hamilton Safeair</td><td></td><td>Fisher Hamilton Stainless Safeair hume hood</td></tr><tr><td>Magnesium sulfate heptahydrate (MgSO4*7H2O)</td><td>Fisher Scientific</td><td>10034 - 99 - 8</td><td>Medium Preparation: Magnesium sulfate heptahydrate</td></tr><tr><td>Methanol</td><td>Sigma-Aldrich</td><td>67-56-1</td><td>Lipid extraction solvent</td></tr><tr><td>Micro bubble Diffuser</td><td>Pentair Aquatic Eco-Systems</td><td>1PMBD075</td><td>This equipment is used for the injection CO2 system</td></tr><tr><td>Microalgae: Chlorella Sorokiniana</td><td>NAABB</td><td>DOE 1412</td><td></td></tr><tr><td>Microoscope</td><td></td><td></td><td>Carl Zeiss 4291097</td></tr><tr><td>Microwave assistant extraction</td><td>MARS, CEM Corportation</td><td></td><td>CEM Mars 5 Xtraction 230/60 Microwave Accelerated Reaction System. Model: 907601</td></tr><tr><td>MnCl2*4H2O</td><td>Sigma-Aldrich</td><td>13446-34-9</td><td>Manganese(II) chloride tetrahydrate</td></tr><tr><td>Mortars</td><td>Fisher Scientific</td><td>FB961B</td><td>Fisherbrand porcelein mortars</td></tr><tr><td>Nitrogen evaporator</td><td>Organomation</td><td></td><td>N-EVAP 112 Nitrogen Evaporatpr (OA-SYS Heating System)</td></tr><tr><td>Oven</td><td>VWR International LLC</td><td>89511-410</td><td>Forced Air Oven</td></tr><tr><td>Paddle Wheel</td><td></td><td></td><td>8-blade horizontal axis propeller. This usually comes as part of the paddlewheel reactor.</td></tr><tr><td>Paddle wheel motor</td><td>Leeson</td><td>M1135042.00</td><td>Leeson, Model: CM34025Nz10C; 1/4 HP; Volts 90; FR 34; 62 RPM.</td></tr><tr><td>Pestles</td><td>Fisher Scientific</td><td>FB961M</td><td>Fisherbrand porcelein pestles</td></tr><tr><td>pH and EC Transmitter</td><td>Hanna Instruments</td><td>HI98143</td><td>Hanna Instruments HI98143-04 pH and EC Transmitter with Galvanic isolated 0-4V.</td></tr><tr><td>pH calibration solutions</td><td>Fisher Scientific</td><td>13-643-003</td><td>Thermo Scientific Orion pH Buffer Bottles</td></tr><tr><td>pH probe sensor</td><td>Hanna Instruments</td><td>HI1006-2005</td><td>Hanna Instruments HI1006-2005 Teflon pH Electrode with matching pin 5m.</td></tr><tr><td>Pippete tips</td><td>Fisher Scientific</td><td>1111-2821</td><td>1000 ul TipOne graduated blue tip in racks</td></tr><tr><td>Pippetter</td><td>Fisher Scientific</td><td>13-690-032</td><td>Eppendorf Reserch plus Variable Adjustable Volume Pipettes: Single-channel</td></tr><tr><td>Plastic cuvettes</td><td>Fisher scientific</td><td>14377017</td><td>BrandTech BRAND Plastic Cuvettes</td></tr><tr><td>Plates</td><td>Fisher scientific</td><td>08-757-100D</td><td>Corning Falcon Bacteriological Petri Dishes with Lid</td></tr><tr><td>Potash</td><td></td><td></td><td>This chemical is used for the optimazed medium preparation. It was bought in a fertilizer local company</td></tr><tr><td>Potassium phosphate dibasic (K2HPO4)</td><td>Sigma-Aldrich</td><td>7758 -11 - 4</td><td>Medium Preparation: Potassium phosphate dibasic</td></tr><tr><td>Pyrex reusable Media Storage Bottles</td><td>Fisher scientific</td><td>06-414-2A</td><td>1 L and 2 L bottels - PYREX GL45 Screw Caps with Plug Seals</td></tr><tr><td>Raceway Pond</td><td></td><td></td><td>Similar equipment can be bought at https://microbioengineering.com/products</td></tr><tr><td>Real Time Optical Density Sensor</td><td>University of Arizona</td><td></td><td>This equipment was design and build by a member of the group</td></tr><tr><td>RS232 Cable</td><td>Sabrent</td><td></td><td>Sabrent USB 2.0 to Serial (9-Pin) DB-9 RS-232 Converter Cable, Prolific Chipset, Hexnuts, [Windows 10/8.1/8/7/VISTA/XP, Mac OS X 10.6 and Above] 2.5 Feet (CB-DB9P)</td></tr><tr><td>Shaker Table</td><td></td><td></td><td>Algae agitation 150 rpm</td></tr><tr><td>Sodium Carbonate (Na2CO3)</td><td>Sigma-Aldrich</td><td>497-19-8</td><td>Sodium carbonate</td></tr><tr><td>Sodium molybdate dihydrate (Na2MoO4*2H2O)</td><td>Sigma-Aldrich</td><td>10102-40-6</td><td>Medium Preparation: Sodium molybdate dihydrate</td></tr><tr><td>Sodium nitrate (NaNO3)</td><td>Sigma-Aldrich</td><td>7631-99-4</td><td>Medium Preparation: Sodium nitrate</td></tr><tr><td>Spectophotometer</td><td>Fisher Scientific Company</td><td>14-385-400</td><td>Thermo Fisher Scientific - 10S UV-Vis GENESTYS Spectrophotometer cylindrical Longpath cell holder; internal reference dectector, Xenon flash lamp; dual silicon photodiode; 240V, 50 to 60Hz selected automatically.</td></tr><tr><td>Test tubes</td><td>Fisher Scientific</td><td>14-961-27</td><td>Fisherbrand Disposable Borosilicate Glass Tubes with Plain End (10 ml)</td></tr><tr><td>Thermocouples type K</td><td>Omega</td><td>KMQXL-125G-6</td><td></td></tr><tr><td>Urea</td><td>Sigma-Aldrich</td><td>2067-80-3</td><td>Urea</td></tr><tr><td>Vacuum filtration system</td><td>Fisher Scientific</td><td>XX1514700</td><td>MilliporeSigma Glass Vacuum Filter Holder, 47 mm. The system includes: Ground glass flask attachment, coarse-frit glass filter support, and flask</td></tr><tr><td>Vacuum pump</td><td>Grainger</td><td></td><td>Marathon Electric AC Motor Thermally protected G588DX - MOD 5KH36KNA510X. HP 1/4. RPM 1725/1425</td></tr><tr><td>Zinc sulfate heptahydrate (ZnSO4*7H2O)</td><td>Sigma-Aldrich</td><td>7446-20-0</td><td>Zinc sulfate heptahydrate</td></tr></tbody></table>

coupling carbon capture from a power plant with semi-automated open raceway ponds for microalgae cultivation

在美国，二氧化碳（CO2）排放总量的35%来自电力行业，其中30%代表天然气发电。微藻可以比植物快10到15倍地生物固定CO2 ，并将藻类生物质转化为感兴趣的产品，如生物燃料。因此，这项研究提出了一种方案，证明了微藻种植与位于美国西南部的天然气发电厂在炎热的半干旱气候下的潜在协同作用。最先进的技术用于通过绿藻种类 小球藻sorokiniana来增强碳捕获和利用，该物种可以进一步加工成生物燃料。我们描述了一个涉及半自动开放式管道池的协议，并讨论了在亚利桑那州图森的图森发电厂进行测试时的性能结果。以烟气为主要碳源控制pH值，培养小 球藻 。使用优化的培养基来培养藻类。作为时间的函数，添加到系统中的 CO2 量受到密切监控。此外，还监测了影响藻类生长速率、生物量生产率和固碳的其他物理化学因素，包括光密度、溶解氧（DO）、电导性（EC）以及空气和池塘温度。结果表明，微藻产量可达0.385 g/L，无灰干重，脂质含量为24%。利用CO2 排放者和藻类养殖者之间的协同机会，可以提供增加碳捕获所需的资源，同时支持藻类生物燃料和生物制品的可持续生产。

我们实验室先前的实验结果表明，使用半自动开放式管道池的微藻培养可以与碳捕获过程相结合。为了更好地理解这两个过程之间的协同作用（图2），我们开发了一个方案，并对其进行了定制，以便在炎热的半干旱气候下的户外条件下培养绿藻物种 小球藻 。天然气烟气是从工业发电站获得的。该协议使用各种技术来评估藻类生物质的生产力:（1）藻类生长使用实时?...

Watch this Scientific Journal Video about Coupling Carbon Capture from a Power Plant with Semi-automated Open Raceway Ponds for Microalgae Cultivation at JoVE.com

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

描述了一种利用天然气发电厂烟气中的二氧化碳在开放式水道池中培养微藻的协议。烟气注入由pH传感器控制，微藻生长通过实时测量光密度来监测。

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 ...

coupling-carbon-capture-from-power-plant-with-semi-automated-open

Universidad de Cartagena UDEC

Research

JoVE Journal

Environment

4.9K 次观看.  University of Arizona. 描述了一种利用天然气发电厂烟气中的二氧化碳在开放式水道池中培养微藻的协议。烟气注入由pH传感器控制，微藻生长通过实时测量光密度来监测。

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

Methods for Performing Crosses in Setaria viridis, a New Model System for the Grasses

Setaria viridis is an emerging model system for C4 grasses. It is closely related to the bioenergy feed stock switchgrass and the grain crop foxtail millet. Recently, the 510 Mb genome of foxtail millet, S. italica, has been sequenced 1,2 and a 25x coverage genome sequence of the weedy relative S. viridis is in progress. S. viridis has a number of characteristics that make it a potentially excellent model genetic system including a rapid generation time, small stature, simple growth requirements, prolific seed production 3 and developed systems for both transient and stable transformation 4. However, the genetics of S. viridis is largely unexplored, in part, due to the lack of detailed methods for performing crosses. To date, no standard protocol has been adopted that will permit rapid production of seeds from controlled crosses.
The protocol presented here is optimized for performing genetic crosses in S. viridis, accession A10.1. We have employed a simple heat treatment with warm water for emasculation after pruning the panicle to retain 20-30 florets and labeling of flowers to eliminate seeds resulting from newly developed flowers after emasculation. After testing a series of heat treatments at permissive temperatures and varying the duration of dipping, we have established an optimum temperature and time range of 48 &deg;C for 3-6 min. By using this method, a minimum of 15 crosses can be performed by a single worker per day and an average of 3-5 outcross progeny per panicle can be recovered. Therefore, an average of 45-75 outcross progeny can be produced by one person in a single day. Broad implementation of this technique will facilitate the development of recombinant inbred line populations of S. viridis X S. viridis or S. viridis X S. italica, mapping mutations through bulk segregant analysis and creating higher order mutants for genetic analysis.

Methods for Performing Crosses in Setaria viridis, a New Model System for the Grasses

We have developed a methodology for performing crosses in Setaria viridis (S. viridis). The method involves pruning the panicle prior to a hot water treatment to kill viable pollen. Crosses are performed following a well-controlled growth regime and typically result in the recovery of 1 to 7 cross-pollinated seed/s per panicle.

方法中进行杂交<em&gt;狗尾草</em&gt;，新模型体系的草

Setaria viridis is an emerging model system for C4 grasses. It is closely related to the bioenergy feed stock switchgrass and the grain crop foxtail ...

科研

环境科学

Analysis of Fatty Acid Content and Composition in Microalgae

A method to determine the content and composition of total fatty acids present in microalgae is described. Fatty acids are a major constituent of microalgal biomass. These fatty acids can be present in different acyl-lipid classes. Especially the fatty acids present in triacylglycerol (TAG) are of commercial interest, because they can be used for production of transportation fuels, bulk chemicals, nutraceuticals (&omega;-3 fatty acids), and food commodities. To develop commercial applications, reliable analytical methods for quantification of fatty acid content and composition are needed. Microalgae are single cells surrounded by a rigid cell wall. A fatty acid analysis method should provide sufficient cell disruption to liberate all acyl lipids and the extraction procedure used should be able to extract all acyl lipid classes.
With the method presented here all fatty acids present in microalgae can be accurately and reproducibly identified and quantified using small amounts of sample (5 mg) independent of their chain length, degree of unsaturation, or the lipid class they are part of.
This method does not provide information about the relative abundance of different lipid classes, but can be extended to separate lipid classes from each other.
The method is based on a sequence of mechanical cell disruption, solvent based lipid extraction, transesterification of fatty acids to fatty acid methyl esters (FAMEs), and quantification and identification of FAMEs using gas chromatography (GC-FID). A TAG internal standard (tripentadecanoin) is added prior to the analytical procedure to correct for losses during extraction and incomplete transesterification.

A method for the determination of fatty acid content and composition in microalgae based on mechanical cell disruption, solvent based lipid extraction, transesterification, and quantification and identification of fatty acids using gas chromatography is described. A tripentadecanoin internal standard is used to compensate for the possible losses during extraction and incomplete transesterification.

脂肪酸组分和含量微藻分析

A method to determine the content and composition of total fatty acids present in microalgae is described. Fatty acids are a major constituent of ...

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 ...

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, ...

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 ...

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 ...

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

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方法中进行杂交

脂肪酸组分和含量微藻分析

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

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

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