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.
增加了对可再生燃料的需求有研究者研究的替代原料如微藻的可行性。固有的优点包括高产量的潜力,利用非耕地和集成废物流。大规模微藻生产系统的营养需求将需要栽培系统具有工业废物资源,如二氧化碳从烟道气和从废水中养分的耦合。存在于这些废物无机污染物有可能导致生物蓄积在微藻生物生产力和限制终端使用产生负面影响。本研究着重于影响的实验评估和14无机污染物(砷,镉,钴,铬,铜,汞,锰,镍,铅,锑,硒,锡,钒和锌)的微绿球藻生长的命运。微藻分别在生长米栽培在光生物反应器照射在984微摩尔米-2秒-1,并保持在pH7EDIA污染与无机污染物的水平预期基础上,商品煤烟气系统中的组成。存在于生物质并在7天的生长周期结束的介质污染物通过冷原子吸收光谱法解析量化汞,并通过电感耦合等离子体质谱法对砷,镉,钴,铬,铜,锰,镍,铅,锑,硒,锡,钒和锌。结果显示N.藻是一个敏感的应变与生物量的统计减少yieldwith引入这些污染物的多金属环境。这里介绍的技术是足够用于量化藻类生长和确定无机污染物的命运。
相比传统的陆地作物微藻已经示出实现由于固有较高的太阳能转换效率1,2-更高的生物量和脂质的产量。培养微藻以高的生产率,需要各种营养素,包括外部碳源的供应。据预计,大规模增长设施将与工业废物流如工业烟道气被集成,以尽量减少生产成本,并在同一时间提供环境整治。工业废弃物的碳通常以气态二氧化碳的形式,并且可以包含有潜力微藻生产产生不利影响的污染物。具体地,从煤衍生的烟道气会产生多种污染物,包括但不限于燃烧产物水和二氧化碳,以及硫和氮,细尘,有机污染物如二恶英和呋喃的氧化物和无机CON组taminants如重金属。大部分这些污染物包括无机物其中一些被称为上微藻生产率重金属的影响还没有被探讨。一些这些元素可以是营养物的适当浓度,但是在较高浓度下它们能产生细胞功能障碍,甚至死亡3。
微藻工业烟道气的集成有直接引入无机污染物进入生长介质的潜力。基于煤烟气具有多种无机元素( 如砷,镉,钴,铬,铜,汞,锰,镍,铅,锑,硒,锡,V和Zn)在不同浓度的其中一些,在低浓度,代表营养微藻生长。无机污染物有一个高亲和力结合微藻,并进一步通过养分转运内部吸附。有些无机污染物( 即钴,铜,锌和锰)是构成酶的组成部分营养素涉及d。在光合作用,呼吸作用等功能3,4。但是,在过量金属和准金属可能是有毒的。其它元素,如铅,镉,锡,锑,硒,砷,汞,不知道以支持细胞功能的任何浓度和代表非营养金属可能培养生长3,5,6负面影响。任何这些污染物的存在具有产生对微藻细胞功能的负面影响的可能性。此外,多种金属与微藻的相互作用复杂增长动力,并有可能影响增长潜力。
大规模的经济已直接关系到培养体系7-19的生产力。此外,因为它代表了99.9和99.4%质量的,分别为20在为任一开放轨道池塘(ORP),或光生物反应器的微藻生长系统(PBR)介质再循环是至关重要的。无机污染物在媒体的存在可能最终限制了米icroalgae生产力和媒体因污染物积聚的回收利用。本研究实验确定的14无机污染物的影响(如,镉,钴,铬,铜,汞,锰,镍,铅,锑,硒,锡,钒和锌)中,在从微藻培养系统的集成预期浓度与煤衍生的烟道气,在N的生产率藻生长在空运PBRS。在这项研究中所用的污染物已被证明不仅存在于煤基烟气但市政废物基烟道气,生物固体基烟道气,城市废水,产生的水,受损的地下水和海水21-23。在这项研究中使用的浓度是基于所预期如果微藻生长系统进行集成了煤基CO 2源与吸收效率在商业PBR系统20证实。详细的计算支持重金属和无机污染物的浓度在Napan呈现等人 24的分析技术被用来理解多数在生物量,媒体和环境的金属的分布。介绍的方法使微藻的生产潜力的评估下,无机污染物的压力和他们的命运结束量化。
盐水微藻N.藻可以成功地生长在设计的生长系统,可重复的结果和高生物量产量。空运混合允许以最小的沉降或生物结垢超过7天的生长周期的良好混合的悬浮培养。横跨荧光银行的最小光变性还被示为不产生在生长明显的差异。
该研究显示重金属浓度代表以煤烟气负面影响生物质生长的整合污染的介质。重复性的研究突出了多金属系统对生产力的影响。在这一过?…
The authors have nothing to disclose.
The authors would like to acknowledge funding from the National Science Foundation (award # 1335550), Utah Water Research Laboratory, Professor Joan McLean and Tessa Guy for their help during the metal/metalloids analysis. The authors also thank Laura Birkhold for her support with the data collection and Danna Olbright.
Chemicals | |||
Sodium chloride | Fisher Scientific | S271-3 | |
Calcium chloride dihydrate | Fisher Scientific | C79-500 | |
Potassium chloride | Fisher Scientific | P217-500 | |
Sodium meta silicate nonahydrate | Fisher Scientific | S408-500 | |
Magnesium sulfate heptahydrate | Fisher Scientific | M63-500 | |
Potassium nitrate | EMD Chemical | PX1520-5 | |
Potassium phosphate monobasic | Fisher Scientific | P285-500 | |
Ammonium ferric citrate | Fisher Scientific | I72-500 | |
Boric acid | Fisher Scientific | A73-500 | |
Sodium molybdate, dihydrate | EMD Chemical | SX0650-2 | |
Manganese chloride tetrahydrate | Fisher Scientific | M87-500 | |
Zinc sulfate heptahydrate | Fisher Scientific | Z68-500 | |
Cupric sulfate pentahydrate | Fisher Scientific | C489-500 | |
Biotin | Acros Organics | 230090010 | |
Thiamine | Acros Organics | 148990100 | |
Vitamin B12 | Acros Organics | 405920010 | |
Copper (II) chloride dihydrate | Sigma-Aldrich | 221783-100G | Irritant, Dangerous to the Environment |
Lead (II) chloride | Sigma-Aldrich | 268690-250G | Toxic, Dangerous to the Environment |
Sodium dichromate dihydrate | Sigma-Aldrich | 398063-100G | Oxidizing, Highly Toxic, Dangerous to the Environment |
Cobalt (II) chloride hexahydrate | Sigma-Aldrich | 255599-100G | Toxic, Dangerous to the Environment |
Nickel (II) chloride hexahydrate | Sigma-Aldrich | 223387-500G | Toxic, Dangerous to the Environment |
Sodium (meta) arsenite | Sigma-Aldrich | 71287 | Toxic, Dangerous to the Environment |
Cadmium chloride | Sigma-Aldrich | 202908-10G | Highly Toxic, Dangerous to the Environment |
Mercury (II) chloride | Sigma-Aldrich | 215465-100G | Toxic, Dangerous to the Environment |
Tin (II) chloride dihydrate | Fisher Scientific | T142-500 | Corrosive. Suitable for Hg analysis. Very hazardous. |
Manganese chloride tetrahydrate | Fisher Scientific | M87-500 | |
Vanadium (V) oxide | Acros Organics | 206422500 | Dangerous to the Environment |
Carbon dioxide | Air Liquide | I2301S-1 | Compressed |
Hydrogen peroxide | H325-500 | Fisher Scientific | 30% in water |
ICP-MS standard | ICP-MS-6020 | High Purity Standards | |
Mercury standard | CGHG1-1 | Inorganic Ventures | 1000±6 µg/mL in 5% nitric acid |
Argon | Air Liquide | Compressed | |
Helium | Air Liquide | Compressed, ultra high purity | |
Hydrogen | Air Liquide | Compressed, ultra high purity | |
Nitric acid | Fisher Scientific | A509-P212 | 67-70% nitric acid, trace metal grade. Caution: manipulate under fume hood. |
Hydrochloric acid | Fisher Scientific | A508-P212 | 35% hydrochloric acid, trace metal grade. Caution: manipulate under fume hood. |
Equipment | |||
Scientific prevacuum sterilizer | Steris | 31626A | SV-120 |
Centrifuge | Thermo Fisher | 46910 | RC-6 Plus |
Spectrophotometer | Shimadzu | 1867 | UV-1800 |
pH controller | Hanna | BL981411 | X4 |
Rotometer, X5 | Dwyer | RMA-151-SSV | T31Y |
Rotometer, X5 | Dwyer | RMA-26-SSV | T35Y |
Water bath circulator | Fisher Scientific | 13-873-45A | |
Compact chiller | VWR | 13270-120 | |
Freeze dryer | Labconco | 7752020 | |
Stir plate | Fisher Scientific | 11-100-49S | |
pH lab electrode | Phidgets Inc | 3550 | |
Inductively coupled plasma mass spectrometer | Agilent Technologies | 7700 Series ICP-MS | Attached to autosampler CETAC ASX-520 |
FIAS 100 | Perkin Elmer Instruments | B0506520 | |
Atomic absorption spectrometer | Perkin Elmer Instruments | AAnalyst 800 | |
Cell heater (quartz) | Perkin Elmer Instruments | B3120397 | |
Microwave | Milestone | Programmable, maximum power 1200 W | |
Microwave rotor | Milestone | Rotor with 24 75 mL Teflon vessels for closed-vessel microwave assisted digestion. | |
Materials | |||
0.2 micron syringe filter | Whatman | 6713-0425 | |
0.2 micron syringe filter | Whatman | 6713-1650 | |
0.45 micron syringe filter | Thermo Fisher | F2500-3 | |
Polystyrene tubes | Evergreen | 222-2094-050 | 17×100 mm w/cap, 16 mL, polysteryne |
Octogonal magnetic stir bars | Fisher scientific | 14-513-60 | Magnets encased in PTFE fluoropolymer |