Algae Meets Fungi: Microalgae-Fungi Co-Pelletization for Biofuel Production
Microalgae-fungi biofuel has significantly less CO2 emissions than fossil fuels, making it much more environmentally friendly. As well, unlike traditional biofuel, microalgae-fungi does not require large masses of agricultural land for production. Thus, microalgae-fungi is an optimal option for biofuel production. This is a cost-effective renewable energy source that can be used in place of regular gas in cars and other means of transportation. By determining the most effective fungi for biofuel production, the threat of the impending environmental damage from pollution can be diminished. This novel experiment determines which fungi: Aspergillus niger, Rhizopus stolonifer or Saccharomyces cerevisiae, is the most effective bioflocculant in the microalgae-fungi co-pelletization process for biofuel production. We hypothesize that when paired with the microalgae Chlorella vulgaris, Rhizopus stolonifer will be the most effective. It has a high lipid content which could enhance the overall production of biofuel. Furthermore, its negative charge will aid with attracting and neutralizing the C. vulgaris colloidal particles resulting in an easier and more efficient removal of microalgae particles. Through the process of bioflocculation, pelletization, esterification and transesterification, the most effective fungi paired with C. vulgaris was determined. This experiment was carried out thoroughly and precisely resulting in a cost-effective solution for the world's current pollution crisis.
The change in NaCl crystals from cubic to octahedral～Sodium polyacrylate stabilizes the {111} face of Miller indices～
When adding 2% or 4% sodium polyacrylate as habit modifier, standard milky-white octahedral NaCl crystals grew gradually in saturated NaCl solution on the bottom of the container. [1] [2] Sodium polyacrylate is well known as a highly water-absorbable polymer with many carboxylate anions. In the case of low concentration (0.01%, 0.02%, 0.05%, 0.1% and 0.5%) sodium polyacrylate many small or microscopic crystals whose shapes were nearly octahedrons and had {111} faces were observed with an optical microscope on the bottoms of the solution containers. In low concentration sodium polyacrylate, octahedral NaCl crystals made up of electrostatically unstable {111} faces grew similarly to crystals in high concentrations of 2% or 4% NaCl. Therefore, by adding sodium polyacrylate to saturated NaCl solution, cleaved rock salt crystals in this sol were observed to find out whether or not a change in crystal morphology from cuboids of {100} faces to octahedrons of {111} faces would occur. Regardless of the sodium polyacrylate concentrations of 0.01%, 0.02%, 0.05%, 0.1%, 0.5% and 2%, all cuboid crystals changed into a pyramidal shape in which four of the side surfaces formed an equilateral triangle. When one side of each equilateral triangle face was rotated so the square face of the crystal was soaked in the NaCl sol, all crystals grew into octahedrons of high transparency. Sodium polyacrylate, even under a low concentration, caused morphological change in the NaCl crystals. Many carboxylate anions in the sodium polyacrylate attracted sodium ions and the repulsive force between the carboxylate anions became weak, excluding the water in the internal space of the polymer. We considered that the stabilizing {111} faces of gathered sodium ions attached to carboxylate anions. Chloride and sodium ions coordinated continuously to minimize the NaCl surface area, growing into an octahedral and lowering the surface energy of the NaCl crystal. [3]
利用共生菌與小球藻建構不須添加培養基且能日夜發電的長效生物光伏電池
¬生物光伏電池(BPV)是一種利用光合自營生物進行光電能量轉換的發電裝置。本研究利用共生菌G76創造不須補充培養基的固態複合型BPV。我們以陽極只含小球藻的BPV為控制組(X-C)，發現在實驗開始24小時之後，BPV電壓開始隨著光照週期產生規律變化，前三個光週期電壓高峰平均值為116.23±2.92 mV, 谷底平均值為87.96±4.48 mV，波動幅度28.27 mV。實驗組為陽極有小球藻與共生菌G76的複合型BPV (X-CG)，同時期電壓高峰平均值為109.23±2.45 mV, 谷底平均值為100.63±0.9 mV，波動幅度8.6 mV。與X-C相比，添加G76會使電壓高峰下降6.02%，但提高谷底電壓14.4%且縮小電壓波動幅度69.58%。目前X-CG已運轉超過1032小時，電壓高峰為95.2mV，衰減幅度19.35%。同時期控制組X-C電壓高峰已下降至61.1mV，衰減幅度90.22%。實驗過程中我們發現在X-C及X-CG組別運作73小時後, 在陰極區都出現了紫黑色微生物(PB1)，同時這些被汙染的BPV的電壓明顯比其他組別更高，將BP1單獨培養並引入陰極後(P-CG), 此一BPV的電壓高峰平均值高達179.3±3.66 mV，谷底平均值則為162.37±1.38 mV，都比X-CG組提高近六成。更重要的是X-CG與P-CG分別能保持日間電壓的92.13%與90.56%，都是非常穩定的BPV。 由以上結果可知, 將共生菌G76加入BPV陽極能提高日夜間的供電穩定度並延長裝置使用壽命，而將PB1引入陰極則能使BPV電壓提高六成以上。若能進一步優化應用這些共生菌, 此種低成本複合型生物光電轉換裝置將有潛力建構出一套不須儲電系統的太陽能發電系統。