scholarly journals Artificial produced water as a medium to grow Chlorella sp. for biodiesel production

2020 ◽  
Vol 148 ◽  
pp. 02005
Author(s):  
Deby Hajjar Rakhmadumila ◽  
Barti Setiani Muntalif

Increased interest in renewable, carbon-neutral energy sources makes processing biodiesel from microalgae has become the objective for many researchers and companies. Some kind of wastewater including municipal, industrial and agricultural wastewaters have been identified as alternate growth mediums. Produced water is the largest byproduct of the oil and natural gas extraction process which constitutes of high concentration of pollutants, such as dissolved nitrogen, phosphorus, dissolved organic carbon, heavy metal and monocyclic aromatic compound like BTEX. The purpose of this study is to identify Chlorella sp. potential for producing lipid in artificial produced water. Variations made in this study consist of 0%, 25%, 50%, 75% and 100% volume of artificial produced water to the control Walne medium. The highest specific growth rate and biomass productivity of Chlorella sp. achieved by culture grown in 25% wastewater with a value of 0.225 day−1 and 0.175 g L−1day−1, respectively. The highest lipid yield and productivity in mixed culture of artificial produced water and Walne medium achieved by culture in 25% artificial produced water with value of 0.231 and 40.48 mg.L−1.day−1. C16 and C18 fatty acids which dominated the lipids of Chlorella sp. in all culture variations indicated that the lipid of Chlorella sp. were suitable for producing high quality biodiesel.

2019 ◽  
Vol 4 (1) ◽  
Author(s):  
Geovanny Huilca ◽  
L Licto ◽  
Ronny Flores

Microalgae had a negative impact on the overall sensory quality. Psychrophilic microalgae live in extremely cold environments, their growth increases because they have enzymes in their structure that only adapt to temperatures below 0 ° C. For this reason, the Sustainable Chemistry Laboratory of the Central University of Ecuador, together with the Ecuadorian Antarctic Institute (INAE), made an expedition in the Greenwich, Roberts, Dee, Barrientos and Antarctic Towers where several microalgae consortia were collected, where 15 samples from Greenwich Island and Roberts were analyzed at 21 days at different temperatures, from which the genera Chlorella sp, Chlorococcum sp and Stichococcus sp. Subsequently, isolation was made in Petri dishes to obtain monoalgal cultures. Each of the isolated genera was massified in a volume of 5 mL until reaching a volume of 250 mL in modified M1 medium at a temperature of 4 ° C and 24 ° C, 5000 lux and a photoperiod of 12:12 hours. The Bligh & Dyer method was used for the extraction of lipids. The values of the lipid concentration showed that the genus Chlorella sp is the highest concentration with a value of 0.2802 mg / mL at 4 ° C and a value of 2.6704 mg / mL at 24 ° C on the 22nd day of its exponential phase in comparison with the genera Chlorococcum and Stichococcus sp.


2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Hsiang-Hui Chou ◽  
Hsiang-Yen Su ◽  
Xiang-Di Song ◽  
Te-Jin Chow ◽  
Chun-Yen Chen ◽  
...  

Abstract Background The increasing emission of flue gas from industrial plants contributes to environmental pollution, global warming, and climate change. Microalgae have been considered excellent biological materials for flue gas removal, particularly CO2 mitigation. However, tolerance to high temperatures is also critical for outdoor microalgal mass cultivation. Therefore, flue gas- and thermo-tolerant mutants of Chlorella vulgaris ESP-31 were generated and characterized for their ability to grow under various conditions. Results In this study, we obtained two CO2- and thermo-tolerant mutants of Chlorella vulgaris ESP-31, namely, 283 and 359, with enhanced CO2 tolerance and thermo-tolerance by using N-methyl-N-nitro-N-nitrosoguanidine (NTG) mutagenesis followed by screening at high temperature and under high CO2 conditions with the w-zipper pouch selection method. The two mutants exhibited higher photosynthetic activity and biomass productivity than that of the ESP-31 wild type. More importantly, the mutants were able to grow at high temperature (40 °C) and a high concentration of simulated flue gas (25% CO2, 80–90 ppm SO2, 90–100 ppm NO) and showed higher carbohydrate and lipid contents than did the ESP-31 wild type. Conclusions The two thermo- and flue gas-tolerant mutants of Chlorella vulgaris ESP-31 were useful for CO2 mitigation from flue gas under heated conditions and for the production of carbohydrates and biodiesel directly using CO2 from flue gas.


2018 ◽  
Vol 77 (6) ◽  
pp. 1660-1672 ◽  
Author(s):  
Rashi Vishwakarma ◽  
Dolly Wattal Dhar ◽  
Sunil Pabbi

Abstract Chlorella sp. MCC 7 and Botryococcus sp. MCC 31 were investigated to enable large-scale biodiesel production from minimal constituents in the growth medium. Response surface methodology (RSM) was used to maximise the biomass productivity and lipid yield using only nitrogen (N), phosphorus (P) and potassium (K) as urea, single super phosphate and muriate of potash. The optimum values were 0.42 g/L nitrogen; 0.14 g/L phosphorus and 0.22 g/L potassium for Chlorella sp.; and 0.46 g/L; 0.14 g/L and 0.25 g/L for Botryococcus sp. Lipid yield of 42% for Chlorella sp. and 52% in Botryococcus sp. was observed. An enhancement in lipid yield by approximately 55% for Chlorella sp. and 73% for Botryococcus sp. was registered as compared to original nutrient medium. Fourier transform infrared (FTIR) analysis of extracted lipids revealed characteristic bands for triglycerides. This study provided utilisation of a practicable nutrient recipe in the form of N, P, K input for enhanced lipid yield from the selected microalgal strains.


1967 ◽  
Vol 45 (1) ◽  
pp. 119-126 ◽  
Author(s):  
J. Basinski ◽  
R. Olivier

Hall effect and resistivity measurements have been made in the temperature range 4.2–360 °K on several samples of n-type GaAs grown under oxygen atmosphere and without any other intentional dopings. The principal shallow donor in this material is considered to be Si. All samples exhibited impurity-band conduction at low temperature. Electron concentrations in the conduction band were calculated, using a two-band model, and then fitted to the usual equation expressing charge neutrality. A value of 2.3 × 10−3 eV was obtained for the ionization energy of the donors, for donor concentration ranging from 5 × 1015 cm−3 to 2 × 1016 cm−3. The conduction in the impurity band was of the hopping type for these concentrations. A value of 3.5 × 1016 cm−3 was obtained for the critical transition concentration of the impurity-band conduction to the metallic type.


2016 ◽  
Vol 78 (7) ◽  
Author(s):  
Costantine Joannes ◽  
Rachel Fran Mansa ◽  
Suhaimi Md. Yasir ◽  
Jedol Dayou

Lately, research on biodiesel production as a renewable and sustainable energy has become increasingly apparent due to the fact that fossil fuel is decreasing and the concern of global warming issues. The third generation of biofuel, which is microalgae-based biodiesel had gained interest over the last decade. The ability of microalgae to grow in various conditions is one of its advantages as the potential and promising feedstock for biodiesel. Microalgae can be cultivated in three modes such as photoautotrophic, heterotrophic and mixotrophic culture mode. Unlike photoautotrophic mode where light is required, the heterotrophic mode mainly utilized carbon compounds to grow. On the other hand, the mixotrophic mode is the condition where light and carbon compounds are supplied for microalgae culturing. This paper investigates the cell growth of Chlorella sp. cultivated in photoautotrophic, heterotrophic and mixotrophic culture mode. It was found that Chlorella sp. was capable of producing the highest cell concentration of 6.67 ± 0.56 x 106 cell mL-1 in the photoautotrophic mode for 23 days of cultivation period. This was 1.3 times and 3.2 times greater than the cell concentration in mixotrophic (5.02 ± 0.49 x 106 cell mL-1) and heterotrophic (2.03 ± 0.29 x 106 cell mL-1) culture, respectively. On the contrary, the highest specific growth rate obtained in the study was from heterotrophic mode (0.32 ± 0.04 day-1) followed by photoautotrophic and mixotrophic mode with 0.26 ± 0.05 day-1 and 0.20 ± 0.04 day-1, respectively. Chlorella sp. cell grew well under the photoautotrophic and mixotrophic mode. However, the insufficient of glucose level had contributed to lower cells productivity in the heterotrophic culture. Therefore, the mixotrophic mode could also be an alternative pathway in microalgae cultivation for biodiesel production if the glucose supplied was adequate and at the suitable level.  


2018 ◽  
Vol 35 (1) ◽  
pp. 47
Author(s):  
Fernando Carvalho Silva ◽  
Kiany Sirley Brandão Cavalcante ◽  
Hilton Costa Louzeiro ◽  
Katia Regina Marques Moura ◽  
Adeilton Pereira Maciel ◽  
...  

Maranhão state in Brazil presents a big potential for the cultivation of several oleaginous species, such as babassu, soybean, castor oil plant, etc... These vegetable oils can be transformed into biodiesel by the transesterification reaction in an alkaline medium, using methanol or ethanol. The biodiesel production from a blend of these alcohols is a way of adding the technical and economical advantages of methanol to the environmental advantages of ethanol. The optimized alcohol blend was observed to be a methanol/ethanol volume ratio of 80 % MeOH: 20 % EtOH. The ester content was of 98.70 %, a value higher than the target of the ANP, 96.5 % (m/m), and the biodiesel mass yield was of 95.32 %. This biodiesel fulfills the specifications of moisture, specific gravity, kinematic viscosity and percentages of free alcohols (methanol plus ethanol) and free glycerin.


2015 ◽  
Vol 3 (1) ◽  
pp. 45-73 ◽  
Author(s):  
Teun Zuiderent-Jerak ◽  
Stans Van Egmond

Valuation studies addresses how values are made in valuation practices. A next - or rather previous - question becomes: what then makes valuation practices? Two oppositional replies are starting to dominate how that question can be answered: a more materially oriented focus on devices of valuation and a more sociologically inclined focus on ineffable valuation cultures. The debate between proponents of both approaches may easily turn into the kind of leapfrog debates that have dominated many previous discussions on whether culture or materiality would play a decisive role in driving history. This paper explores a less repetitive reply. It does so by analyzing the puzzling case of the demise of solidarity as a core value within the recent Dutch health care system of regulated competition. While “solidarity among the insured” was both a strong cultural value within the Dutch welfare-based health system, and a value that was built into market devices by health economists, within a fairly short time “fairness” became of lesser importance than “competition”. This makes us call for a more historical, relational, and dynamic understanding of the role of economists, market devices, and of culture in valuation studies.


2018 ◽  
Vol 122 ◽  
pp. 80-88 ◽  
Author(s):  
Richa Katiyar ◽  
Randhir K. Bharti ◽  
B.R. Gurjar ◽  
Amit Kumar ◽  
Shalini Biswas ◽  
...  

2021 ◽  
Vol 10 (3) ◽  
pp. 321-326
Author(s):  
Muhammad Abdul Zaky ◽  
Rini Pramesti ◽  
Ali Ridlo

Indonesia menghasilkan 64 juta ton sampah di laut dan 3,2 juta ton di antaranya adalah plastik. Pencemaran tersebut mendorong pencarian plastik berbahan dasar ramah lingkungan yang dapat terurai . Bioplastik yang merupakan alternatif kemasan plastik dan bersifat ramah lingkungan. Berbagai bahan dasar pembuatan bioplastik telah ditemukan, salah satunya dasar karagenan. Penelitian ini bertujuan mengetahui karakteristik bioplastik hasil ekstraksi karagenan rumput laut Kappaphycus alvarezii dan mengetahui konsentrasi terbaik bioplastik hasil ekstraksi karagenan berdasarkan tebal film, kuat tarik dan persen pemanjangan. Metode yang digunakan adalah eksperimental laboratoris. Ekstraksi menggunakan perlakuan alkali dengan larutan KOH. Proses ekstraksi menghasilkan tepung karagenan yang digunakan sebagai bahan pembuatan bioplastik. Pembuatan bioplastik menggunakan campuran karagenan dengan 5 variasi massa karagenan, gliserol 10 ml dan 1,2 g CMC. Hasil ekstraksi menghasilkan rendemen 41,12%, kadar air 2,75%, kadar abu 19,10%, kekuatan gel 452,38 dyne/cm2dan viskositas 8,33 cP. Hasil penelitian tentang nilai ketebalan film bioplastik terbaik pada karagenan 3,5 g yaitu 0,093 mm, kuat tarik terbaik pada 1,5 g yaitu 2,587 Mpa, elongasi terbaik pada karagenan 1,5 g sebesar 44,992%. Berdasarkan data tersebut, hasil penelitian ini dapat diaplikasikan sebagai kemasan primer produk pangan. Sea pollution in Indonesia has increased every year with one of the pollutants is plastic. Indonesia produces 64 million tons of waste at sea and 3.2 million tons of which are plastic. The pollution is encouraging researchers to create plastic-based materials that are environmentally friendly and biodegradable. Bioplastics are an environmentally friendly alternative to plastic packaging. This study aims to determine the characteristics of bioplastics extracted from Kappaphycus alvarezii seaweed carrageenan and determine the best concentration of bioplastics from the extraction based on film thickness, tensile strength, and elongation percentage. The method that used in the research is experimental laboratory. The extraction uses alkaline treatment with KOH solution. The extraction process produces carrageenan flour which will be used as a bioplastic material. Making bioplastics using a mixture of carrageenan with 5 variations of concentration, glycerol 10 ml and 1.2 g CMC. The results of extraction showing 41.12% yield, 2.75% moisture content, 19.10% ash content, 452.38 dyne / cm2 gel strength, 8.33 cP viscosity. Carrageenan with the best value of bioplastic film thickness is 3.5 g which is 0.093 mm, the best tensile strength is achieved at 1.5 g with a tensile strength value of 2.587 MPa, the best elongation is achieved at 1.5 g with a value of 44.992%. Based on data showing that this research can be applied as primary packaging for food products.


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