scholarly journals Toxicity assessment of residual biomass of microalgae Chlorella sorokiniana

2019 ◽  
Vol 59 (7) ◽  
pp. 92-98
Author(s):  
Yulia A. Smyatskaya ◽  
Keyword(s):  
Heat Treatment ◽  
Toxic Effect ◽  
Daphnia Magna ◽  
Chlorella Vulgaris ◽  
Test Object ◽  
Experimental Studies ◽  
Chlorella Sorokiniana ◽  
Lipid Complex ◽  
Residual Biomass

In this paper, the determination of the toxicity of residual biomass of microalgae Chlorella sorokiniana by the method of biotesting with use of the test – object Daphnia magna Straus and algae Chlorella vulgaris Beijer. Determination of the toxic effect is necessary for planning the possibility of further use of waste, as a sorption material for wastewater treatment, as a co-substrate for fermentation of organic waste and in the production of biogas. The residual biomass of Chlorella sorokiniana microalgae is formed after the extraction of valuable components (lipid complex, pigments, proteins, etc.). The extraction of the lipid complex uses organic solvents (hexane, ethyl alcohol), the remains of which can remain in the residual biomass. Determined the acute toxicity of residual biomass of microalgae by water extraction with the help of test-object Daphnia magna Straus and the test object microalgae Chlorella vulgaris Beijer according to standard methods. According to the study waste source of residual biomass to treat the IV class of hazard, ЛКР50-48 = 11.7; БКР10-48 = 35.48. To reduce the toxic effect is proposed to conduct heat treatment. Heat treatment was carried out in a muffle furnace at a temperature of 105 oС for 1 hour. Experimental studies using Daphnia magna Straus crustaceans showed that the value of A is 3%, which indicates the absence of toxicity of residual biomass. When using microalgae toxicity criterion was also not exceeded in any dilution of water, including its original undiluted version. It is established that after heat treatment the residual biomass of microalgae becomes non-toxic and has a V hazard class. The results indicate the possibility of re-use of residual biomass.

scholarly journals Determination of biogas potential of residual biomass of microalgae Chlorella Sorokiniana

2019 ◽  
Vol 403 ◽  
pp. 012225 ◽  
Author(s):  
Alexander Chusov ◽  
Vladimir Maslikov ◽  
Viacheslav Zhazhkov ◽  
Yuliya Pavlushkina
Keyword(s):  
Chlorella Sorokiniana ◽  
Residual Biomass

scholarly journals Development of Full-Cycle Utilization of Chlorella sorokiniana Microalgae Biomass for Environmental and Food Purposes

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2648 ◽  
Author(s):  
Natalia Politaeva ◽  
Yulia Smyatskaya ◽  
Rafat Al Afif ◽  
Christoph Pfeifer ◽  
Liliya Mukhametova
Keyword(s):  
Unsaturated Fatty Acids ◽  
Energy Content ◽  
Lipid Extraction ◽  
Chlorella Sorokiniana ◽  
Potentially Toxic Elements ◽  
Lipid Complex ◽  
Residual Biomass ◽  
Heat Treated ◽  
Microalgae Biomass ◽  
Additional Fuel

The application of microalgae biomass of Chlorella sorokiniana as environmentally friendly biosorbents for removing potentially toxic elements (PTE) from water and as a source of biofuel has been thoroughly studied. In this paper, we investigate its physicochemical properties infrared spectroscopy (IR spectra), microstructure, adsorption properties); we have managed to isolate the lipid complex, which amounted to 20% of dry biomass. Studies of the lipid complex showed that 80.02% of lipids are unsaturated fatty acids (C18:1, C18:2, C18:3). Additionally, we have investigated the efficiency of using the residual biomass obtained after lipid extraction for water purification from rare-earth metals (REM) and PTE. To increase the sorption properties of residual biomass, its thermal modification was carried out and sorption materials based on heat-treated residual biomass and chitosan were created. The physicochemical and mechanical properties of the obtained sorption materials were studied. The total sorption capacity was 31.9 mg/g for REM and 349.7 mg/g for PTE. Moreover, we propose a new method for the disposal of spent sorbents as additional fuel. Spent sorbents can be considered to be biofuel in terms of energy content (20.7 MJ*kg−1). The results of this study provide the basis for increased use of microalgae.

Biogas production by fermentation of residual biomass of microalgae and duckweed

2019 ◽  
Vol 60 (12) ◽  
pp. 146-151
Author(s):  
Yulia A. Smyatskaya ◽  
◽  
Natalia A. Politaeva ◽  
Keyword(s):  
Activated Sludge ◽  
Fermentation Process ◽  
Biogas Production ◽  
Lemna Minor ◽  
Experimental Studies ◽  
Chlorella Sorokiniana ◽  
Raw Material ◽  
Fermentation Processes ◽  
Residual Biomass

This article discusses the use of residual biomass of microalgae Chlorella Sorokiniana and the residual biomass of duckweed Lemna minor (OBR) as a raw material for biogas production. Residual biomass is formed after the treatment of valuable components from the biomass of microalgae and duckweed. The fermentation process was carried out using an inoculant – lyophilized activated sludge with the addition of vitamins and macro- and microelements. Experimental studies were carried out using the Anaerobes Testsystem AMPT-II system, which made it possible to maintain a temperature of 37 °C. When fermenting 2.1 g of OBH, it was possible to obtain 205 ml of methane, and when fermenting 2.5 g of OBR, 256 ml of methane was released, while in the control bioreactor 45 ml of methane was formed. Obtaining biogas by fermenting the residual biomass of microalgae and duckweed can significantly increase the amount of methane released, which is part of biogas. The lipids and carbohydrates included in the biomass can intensify the fermentation processes and increase the amount of biogas released.

Improvement Of Curvilinear Diagrams Of Concrete Deformation

2019 ◽  
pp. 99-104
Keyword(s):  
Reinforced Concrete ◽  
Peak Load ◽  
Experimental Studies ◽  
Concrete Structures ◽  
Deformation Model ◽  
Reinforced Concrete Structures ◽  
Significant Difference ◽  
Deformation Diagrams

Problems when calculating reinforced concrete structures based on the concrete deformation under compression diagram, which is presented both in Russian and foreign regulatory documents on the design of concrete and reinforced concrete structures are considered. The correctness of their compliance for all classes of concrete remains very approximate, especially a significant difference occurs when using Euronorm due to the different shape and sizes of the samples. At present, there are no methodical recommendations for determining the ultimate relative deformations of concrete under axial compression and the construction of curvilinear deformation diagrams, which leads to limited experimental data and, as a result, does not make it possible to enter more detailed ultimate strain values into domestic standards. The results of experimental studies to determine the ultimate relative deformations of concrete under compression for different classes of concrete, which allowed to make analytical dependences for the evaluation of the ultimate relative deformations and description of curvilinear deformation diagrams, are presented. The article discusses various options for using the deformation model to assess the stress-strain state of the structure, it is concluded that it is necessary to use not only the finite values of the ultimate deformations, but also their intermediate values. This requires reliable diagrams "s–e” for all classes of concrete. The difficulties of measuring deformations in concrete subjected to peak load, corresponding to the prismatic strength, as well as main cracks that appeared under conditions of long-term step loading are highlighted. Variants of more accurate measurements are proposed. Development and implementation of the new standard GOST "Concretes. Methods for determination of complete diagrams" on the basis of the developed method for obtaining complete diagrams of concrete deformation under compression for the evaluation of ultimate deformability of concrete under compression are necessary.

Energetic properties of peat saturated with petroleum products

2020 ◽  
Vol 13 (2) ◽  
pp. 105-109
Author(s):  
E. S. Dremicheva
Keyword(s):  
Crude Oil ◽  
Diesel Fuel ◽  
Energy Use ◽  
Experimental Studies ◽  
Calorific Value ◽  
Petroleum Products ◽  
Ash Content ◽  
Motor Oil ◽  
Initial Sample

This paper presents a method of sorption using peat for elimination of emergency spills of crude oil and petroleum products and the possibility of energy use of oil-saturated peat. The results of assessment of the sorbent capacity of peat are presented, with waste motor oil and diesel fuel chosen as petroleum products. Natural peat has been found to possess sorption properties in relation to petroleum products. The sorbent capacity of peat can be observed from the first minutes of contact with motor oil and diesel fuel, and significantly depends on their viscosity. For the evaluation of thermal properties of peat saturated with petroleum products, experimental studies have been conducted on determination of moisture and ash content of as-fired fuel. It is shown that adsorbed oil increases the moisture and ash content of peat in comparison with the initial sample. Therefore, when intended for energy use, peat saturated with petroleum products is to be subjected to additional drying. Simulation of net calorific value has been performed based on the calorific values of peat and petroleum products with different ratios of petroleum product content in peat and for a saturated peat sample. The obtained results are compared with those of experiments conducted in a calorimetric bomb and recalculated for net calorific value. A satisfactory discrepancy is obtained, which amounts to about 12%. Options have been considered providing for combustion of saturated peat as fuel (burnt per se and combined with a solid fuel) and processing it to produce liquid, gaseous and solid fuels. Peat can be used to solve environmental problems of elimination of emergency spills of crude oil and petroleum products and as an additional resource in solving the problem of finding affordable energy.

EXPERIMENTAL STUDIES OF REINFORCED CONCRETE STRUCTURES WITH CROSS-SHAPED SPATIAL CRACK UNDER TORSION WITH BENDING

2020 ◽  
Vol 92 (6) ◽  
pp. 13-25
Author(s):  
Vl.I. KOLCHUNOV ◽  
◽  
A.I. DEMYANOV ◽  
M.M. MIHAILOV ◽  
◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Experimental Determination ◽  
Calculation Method ◽  
Experimental Studies ◽  
Concrete Structures ◽  
Design Parameters ◽  
Reinforced Concrete Structures ◽  
Experimental Scheme

The article offers a method and program for experimental studies of reinforced concrete structures with cross-shaped spatial crack under torsion with bending, the main purpose of which is to check the design assumptions and experimental determination of the design parameters of the proposed calculation method. The conducted experimental studies provide an opportunity to test the proposed calculation apparatus and clarify the regularities for determining deflections, angles of rotation of extreme sections, and stresses in the compressed zone of concrete. For analysis, the article presents a typical experimental scheme for the formation and development of cracks in the form of a sweep, as well as characteristic graphs of the dependence of the angles of rotation of end sections.

EFFECT OF KAGOCEL PREPARATION ON THE GENERATIVE FUNCTION OF EXPERIMENTAL ANIMALS AT ITS ADMINISTRATION IN THE INFANTILE PERIOD OF THEIR DEVELOPMENT

2017 ◽  
pp. 42-49
Author(s):  
T. A. Borovskaya ◽  
M. E. Poluektova ◽  
A. V. Vychuzhanina ◽  
V. A. Mashanova ◽  
Yu. A. Shchemerova
Keyword(s):  
Toxic Effect ◽  
Reproductive System ◽  
Safety Profile ◽  
Therapeutic Dose ◽  
Antiviral Drug ◽  
Experimental Studies ◽  
Reproductive Age ◽  
Pathological Changes ◽  
Pediatric Practice ◽  
Experimental Animals

In experimental studies on rats (males, females) at their infantile stage starting from 10 days, a potential delayed toxic effect of the antiviral drug Kagocel on the reproductive system was studied. The drug was administered for 12 days in a therapeutic dose and at a dose 10-fold higher than the therapeutic one. Reproductive safety was estimated after animals reached the reproductive age (2.5 months). It was found out that the drug, when administered in both doses, does not decrease the fertility of animals, does not induce morphological and pathological changes in the sex glands, and does not have toxic effect on the offspring. Obtained data characterize Kagocel as a preparation with a wide reproductive safety profile and show that it can be used in pediatric practice for infants.

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