Improvement of lab-scale production of microalgal carbohydrates for biofuel production

This work studied the improvement of biomass and carbohydrate (glucose and xylose) lab–scale productivity in Chlorella vulgaris UTEX 1803 through the use of the carbon/nitrogen ratio. In order to do so, mixotrophic cultures were made by the modification of initial concentration of CH3COONa (5, 10 and 20 mM) and NaNO3 (0.97, 1.94 and 2.94 mM). All treatments were maintained at 23 ± 1ºC, with light/dark cycles of 12h : 12h for 5 days.It was found that in addition to the carbon/nitrogen ratio, time also influences the concentration of biomass and carbohydrates. The treatment containing 10 mM acetate: 1.94 mM nitrate, reached a concentration of 0.79 g/L of biomass, 76.9 μg/mL of xylose and 73.7 μg/mL of glucose in the fifth day. However, the treatmentcontaining 20 mM acetate: 0.97 mM nitrate produced 1.04 g/L of biomass, 78.9 μg/mL of xylose and 77.2 μg/mL of glucose in the third day, while in the same day the treatment containing 0 mM acetate: 2.94 mM nitrate, produced 0.55 g/L of biomass, 40.2 μg/mL of xylose and 31.3 μg/mL of glucose.The use of carbon/nitrogen ratios improved biomass productivity (from 0.55 to 1.04 g/L) as well as xylose (from 40.2 to 78.9 μg/mL) and glucose (from 31.3 to 77.2 μg/mL) concentration, representing an improvement of up to two times the production of both biomass and carbohydrates in only 3 days of culture.

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A Review of Energy Consumption in the Acquisition of Bio-Feedstock for Microalgae Biofuel Production

Sustainability ◽

10.3390/su13168873 ◽

2021 ◽

Vol 13 (16) ◽

pp. 8873

Author(s):

Minghao Chen ◽

Yixuan Chen ◽

Qingtao Zhang

Keyword(s):

Energy Consumption ◽

Large Scale ◽

Fossil Fuels ◽

Biomass Concentration ◽

Biomass Productivity ◽

Biofuel Production ◽

Scale Production ◽

Culture Methods ◽

Cultivation System ◽

Cultivation Systems

Microalgae biofuel is expected to be an ideal alternative to fossil fuels to mitigate the effects of climate change and the energy crisis. However, the production process of microalgae biofuel is sometimes considered to be energy intensive and uneconomical, which limits its large-scale production. Several cultivation systems are used to acquire feedstock for microalgal biofuels production. The energy consumption of different cultivation systems is different, and the concentration of culture medium (microalgae cells contained in the unit volume of medium) and other properties of microalgae vary with the culture methods, which affects the energy consumption of subsequent processes. This review compared the energy consumption of different cultivation systems, including the open pond system, four types of closed photobioreactor (PBR) systems, and the hybrid cultivation system, and the energy consumption of the subsequent harvesting process. The biomass concentration and areal biomass production of every cultivation system were also analyzed. The results show that the flat-panel PBRs and the column PBRs are both preferred for large-scale biofuel production for high biomass productivity.

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Assessment of Chlorella vulgaris, Scenedesmus obliquus, and Oocystis minuta for removal of sulfate, nitrate, and phosphate in wastewater

International Journal of Energy and Environmental Engineering ◽

10.1007/s40095-019-00333-0 ◽

2020 ◽

Vol 11 (3) ◽

pp. 311-326 ◽

Cited By ~ 3

Author(s):

Sheriff Olalekan Ajala ◽

Matthew L. Alexander

Keyword(s):

Chlorella Vulgaris ◽

Scenedesmus Obliquus ◽

Biomass Productivity ◽

Growth Conditions ◽

Phosphate Removal ◽

Biofuel Production ◽

Protein Accumulation ◽

Contaminant Removal ◽

Biochemical Component ◽

Sulfate Removal

AbstractApplication of wastewater for algal biomass production can not only lead to production of thousands of tons of biomass for subsequent biofuel production, but also can provide for significant removal of contaminants in wastewater. The aim of the present study is to evaluate the growth, contaminant removal, and biochemical component (lipid, carbohydrate, and protein) accumulation potential of Chlorella vulgaris, Scenedesmus obliquus, and Oocystis minuta cells in wastewater supplemented with different concentrations of sulfate, nitrate, and phosphate. The results show maximum biomass productivity of 33, 19, and 98 mg dw/L/d for C. vulgaris, S. obliquus, and O. minuta, respectively. Phosphate removal (more than 90%) was highest in the culture with O. minuta; about 93% nitrate was removed by C. vulgaris, and the highest sulfate removal of 36% was observed in the culture with S. obliquus. The biochemical composition of the microalgae cells is in the ranges of 22–65% carbohydrate, 19–38% protein, and 8–17% lipid. This indicates that carbohydrate and protein are preferentially accumulated as compared to lipids under the growth conditions investigated for each of the microalgae strains.

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Cultivation of Chlorella vulgaris in manure-free piggery wastewater with high-strength ammonium for nutrients removal and biomass production: Effect of ammonium concentration, carbon/nitrogen ratio and pH

Bioresource Technology ◽

10.1016/j.biortech.2018.11.019 ◽

2019 ◽

Vol 273 ◽

pp. 203-211 ◽

Cited By ~ 25

Author(s):

Hongli Zheng ◽

Xiaodan Wu ◽

Guyue Zou ◽

Ting Zhou ◽

Yuhuan Liu ◽

...

Keyword(s):

Biomass Production ◽

Chlorella Vulgaris ◽

High Strength ◽

Ammonium Concentration ◽

Nutrients Removal ◽

Piggery Wastewater ◽

Production Effect ◽

Carbon Nitrogen Ratio ◽

Nitrogen Ratio

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Environmental significance of atrazine in aqueous systems and its removal by biological processes: an overview

Global NEST Journal ◽

10.30955/gnj.000306 ◽

2013 ◽

Vol 8 (2) ◽

pp. 159-178 ◽

Cited By ~ 2

Keyword(s):

Drinking Water ◽

Ground Water ◽

Water Environment ◽

Biological Processes ◽

Biological Degradation ◽

Environmental Significance ◽

Carbon And Nitrogen ◽

Carbon Nitrogen Ratio ◽

Nitrogen Ratio ◽

Living Organisms

Atrazine, a chlorinated s-triazine group of herbicide is one of the most widely used pesticides in the World. Due to its extensive use, long half-life and various toxic properties, it has very high environmental significance. Up to 22 mg l-1 of atrazine was found in ground water whereas permissible limit of atrazine is in ppb level in drinking water. As per Indian standard there should not be any pesticide present in drinking water. Among many other treatment processes available, Incineration, adsorption, chemical treatment, phytoremediation and biodegradation are the most commonly used ones. Biological degradation of atrazine depends upon various factors like the operating environment, external carbon and nitrogen sources, carbon/ nitrogen ratio (C/N), water content and the bacterial strain. Although, general atrazine degradation pathways are available, the specific pathways in specific conditions are not yet clearly defined. In this paper extensive review has been made on the occurrence of atrazine in surface and ground water bodies, probable sources and causes of its occurrence in water environment, the toxicity of atrazine on various living organisms and its removal by biological processes.

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The Organic Matter and Nitrogen Content and Carbon-Nitrogen Ratio of Cecil Soil as Influenced by Different Cropping Systems on Classes II, III, and IV Land

Soil Science Society of America Journal ◽

10.2136/sssaj1950.036159950014000c0046x ◽

1950 ◽

Vol 14 (C) ◽

pp. 203-208

Author(s):

G. W. Gosdin ◽

Matthias Stelly ◽

W. E Adams

Keyword(s):

Organic Matter ◽

Nitrogen Content ◽

Cropping Systems ◽

Carbon Nitrogen Ratio ◽

Nitrogen Ratio

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Effects of Organic Fertilizer on Bok Choy Growth and Quality in Hydroponic Cultures

Agronomy ◽

10.3390/agronomy11030491 ◽

2021 ◽

Vol 11 (3) ◽

pp. 491

Author(s):

Kazuki Kano ◽

Hiroaki Kitazawa ◽

Keitaro Suzuki ◽

Ani Widiastuti ◽

Hiromitsu Odani ◽

...

Keyword(s):

Plant Root ◽

Oxygen Deficiency ◽

Organic Fertilizer ◽

Corn Steep Liquor ◽

Ascorbic Acid Content ◽

Growth And Yield ◽

Significant Difference ◽

Carbon Nitrogen Ratio ◽

Nitrogen Ratio ◽

Steep Liquor

Effects of corn steep liquor (organic fertilizer, OF) and conventional chemical fertilizer (CF) on the growth and yield of bok choy (Brassica rapa var. chinensis) in summer and autumn hydroponic growing systems were compared. When OF and CF were applied with the same amount of total nitrogen in summer cultivation, there was no significant difference between yields; however, the growth rate in OF was slower than in CF. When OF was applied with twice the amount of nitrogen in CF (OF2), bok choy growth and yield were significantly inhibited in summer cultivation, likely owing to dissolved oxygen deficiency and different rates of nitrification and nitrogen absorbance by the plant root. Although the contents of potassium, calcium, and magnesium in bok choy showed no difference among the three treatments in both cultivation seasons, the carbon/nitrogen ratio tended to be higher in OF and OF2 than in CF. Lower nitric acid and higher ascorbic acid content was found in OF and OF2 than in CF. Overall, our results suggest that a comparable yield is expected by using the same nitrogen amount with a conventional recipe of chemical fertilization in autumn cultivation. However, further improvement of hydroponic management is needed in summer cultivation.

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A political ontology for Europe: Roberto Esposito’s instituent paradigm

Continental Philosophy Review ◽

10.1007/s11007-021-09542-z ◽

2021 ◽

Author(s):

Rita Fulco

Keyword(s):

Political Theology ◽

Political Crisis ◽

Recent Proposal ◽

Political Ontology ◽

The Third ◽

European Crisis ◽

Do So

AbstractThe aim of my article is to relate Roberto Esposito’s reflections on Europe to his more recent proposal of instituent thought. I will try to do so by focusing on three theoretical cornerstones of Esposito’s thought: the first concerns the evidence of a link between Europe, philosophy and politics. The second is deconstructive: it highlights the inadequacy of the answers of the most important contemporary ontological-political paradigms to the European crisis, as well as the impossibility of interpreting this crisis through theoretical-political categories such as sovereignty. The third relates more directly to the proposal of a new political ontology, which Esposito defines as instituent thought. Esposito’s discussion of political theology is the central theoretical nucleus of this study. This discussion will focus, in particular, on the category of negation, from which any political ontology that is based on pure affirmativeness or absolute negation is criticized. In his opinion, philosophical theories developed on the basis of these assumptions have proved to be incomplete or ineffective in relation to the current European and global philosophical and political crisis. Esposito therefore perceives the urgent need to propose a line of thought that is neither negatively destituent (post-Heideggerian), nor affirmatively constituent (post-Deleuzian, post-Spinozian), but instituent (neo-Machiavellian), capable of thinking about order through conflict (the affirmative through the negative). Provided that we do not think of the institution statically–in a conservative sense–but dynamically, as constant instituting in which conflict can become an instrument of a politics increasingly inspired by justice.

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