scholarly journals Adhesion abilities and biosorption of Cd and Mg by microorganisms - first step for eco-friendly beneficiation of phosphate ore

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Hakim Rabia ◽  
Malek Ould Hamou ◽  
Katarzyna Kasperkiewicz ◽  
Jolanta Brożek ◽  
Maria Augustyniak
Keyword(s):  
Raw Materials ◽  
Rhodococcus Erythropolis ◽  
Phosphate Ore ◽  
Chemical Reagents ◽  
Natural Mixture ◽  
Microbial Strains ◽  
Ph Range ◽  
Favorable Conditions ◽  
Unique Composition ◽  
Apatite Surface

Abstract Chemical reagents used in traditional mineral processing can be toxic and hazardous for the environment. Therefore, the use of biotechnological methods is becoming increasingly important. Great hopes are being placed in the use of microorganisms for bio-beneficiation of raw materials. However, assessment of adhesion abilities of bacteria onto minerals surface as well as biosorption of metals are essential steps before designing final process of each ore beneficiation. The main aim of this work was an investigation of biosorption of Cd and Mg, as well as adhesion abilities of five microorganism species with minerals included in the natural mixture of phosphate ore form Djebel Onk, Algeria. The ore, due to its unique composition, created conditions for adhesion of all five tested microbial strains onto apatite surface during incubation at pH 3. Moreover, Rhodococcus erythropolis CD 130, Pseudomonas fluorescens and Escherichia coli adhered distinctly onto apatite surface during incubation at pH 7. Incubation lasting 20 min at pH 4-6 created the most favorable conditions for biosorption of metals by B. subtilis and adhesion of cells. In case of C. albicans, biosorption of metals as well as adhesion of cells onto the mineral surface were more effective after longer time and in a wider pH range.

scholarly journals Investigation of the Palaeolithic and Mesolithic Sites in the Don Basin on the Territory of Volgograd Region

2020 ◽  
pp. 167-187
Author(s):  
Stanislav Remizov
Keyword(s):  
Raw Materials ◽  
Volga Basin ◽  
Upper Paleolithic ◽  
Russian Plain ◽  
Small Rivers ◽  
Stone Age ◽  
Volgograd Region ◽  
Stone Industry ◽  
Xix Century ◽  
Favorable Conditions

The locations of the Stone Age on the Volgograd region territory have been known since the beginning of the XIX century. However, purposeful Stone Age sites explorations had only started after the Sukhaya Mechetka site was discovered by A.P. Koptev and M.N. Grischenko in 1951. The data accumulated on series of stratified sites in Volgograd Region makes it possible to outline two significant groups of them. One of the groups belongs to the Lower Volga basin. The other group is associated with the ramified network of gullies and ravines and multiple tributaries of the Don. The Don is the fourth longest river on the Russian Plain; its basin taken in the Volgograd Region is several times larger than the Volga basin taken in the area. The relatively flat landscape of the Don plain, saturated with small rivers, gullies and ravines, as well as stone raw materials available for mining, have been creating favorable conditions for human habitation since the Middle Paleolithic. The well-known Paleolithic and Mesolithic sites are found both in the watersheds and in the floodplain-terrace areas of the Middle Don. The near-mouth section of the Kurmoyarsky Aksai river – the Don tributary in Kotelnikovo District – and the surroundings of Kremenskaya village in Kletskaya District are standing out in terms of being studied. The stone industry detected in the lower layers of the multilayered site Schlyakh indicates that the Don plain was inhabited by people during the Middle to the Upper Paleolithic transition. The prospects of further searches for Stone Age sites in the Middle Don Basin had already been proven by the discovery of at least forty sites in previous decades. Further archaeological research will help to discover new stratified sites with impressive collections of stone and bone items, which will make it possible to draw analogies with synchronous sites in the territories adjacent to the Volgograd region.

Synthesis of Belite-Ye’elimite-Ternesite Cement Clinker

2021 ◽  
Vol 1036 ◽  
pp. 223-229
Author(s):  
Dao Peng Ji ◽  
Su Hua Ma ◽  
Wei Feng Li
Keyword(s):  
Raw Materials ◽  
Stable Condition ◽  
Cement Clinker ◽  
Low Carbon ◽  
Calcination Time ◽  
Chemical Reagents ◽  
Sintering Time ◽  
Wide Range ◽  
Low Energy Consumption ◽  
Low Carbon Emission

Belite - ye’elimite - ternesite (BYT) cement clinker has attracted much attention due to its advantages of wide range of raw materials, low energy consumption and low carbon emission compared with ordinary portland cement (OPC). In this experiment, chemical reagents were used as raw materials. The effects of calcination temperature and calcination time on clinker synthesis were studied. The best sintering temperature was determined by sintering in rang of 1150-1300°C (setting a temperature point every 30 °C), and then the samples were sintering for 1-6 hours (setting every hour) to determine the best sintering time. The stable condition of the BYT clinker was determined. The phase composition and microstructure of cement clinker were analyzed by X-ray powder diffraction (XRD) Rietveld refinement and Scanning Electronic Microscopy (SEM). The results showed that the desired clinker could be obtained by sintering at 1210°C for 2 hours. In the presence of C4A3$, the hydration of C5S2$ was accompanied by the formation of gypsum and the precipitation of ettringite.

Setting Time of Powder Composites and the Effect of Chemical Reagents

2021 ◽  
Vol 899 ◽  
pp. 675-680
Author(s):  
Soyibon S. Negmatov ◽  
Zokirkhon T. Munavvarkhanov ◽  
Murotbek B. Boydadaev ◽  
Alloberdi M. Madraximov
Keyword(s):  
Raw Materials ◽  
Setting Time ◽  
Chemical Reagents ◽  
Secondary Raw Materials ◽  
Powder Composites

Additives were selected and a method for modifying the structure of gypsum-containing materials for construction purposes and a method for their dispersion were developed. Based on the selected modifiers, effective compositions of composite gypsum-containing materials based on local and secondary raw materials were developed, and an increase in their strength and resistance to water was established.

Equilibrium and Kinetics Studies of Phosphate Removal from Solution onto a Hydrothermally Modified Al-Si-Fe-Ca Composite Adsorbent

2014 ◽  
Vol 787 ◽  
pp. 128-134
Author(s):  
Qiong Wu ◽  
Rui Rong You ◽  
Qiu Ping Wu ◽  
Fei Yun Chen ◽  
Yan Yu
Keyword(s):  
Composite Material ◽  
Wastewater Treatment ◽  
Raw Materials ◽  
Phosphate Removal ◽  
Sorption Data ◽  
Composite Adsorbent ◽  
Equilibrium And Kinetics ◽  
Pseudo Second Order ◽  
Ph Range ◽  
Maximum Removal

A novel Al–Si–Fe–Ca composite material for phosphate removal in wastewater treatment was made by using Al (OH)3,Fe2O3,CaO and silica powder as raw materials. Sorption data modelling with a pH range of 3–12, P concentrations of 3,5,7,9, 11,13, 15mg L−1, and an ambient temperature of 23°C indicated that an optimal removal of P occurred at pH 6.0. A maximum removal of 99.68% was found for 11mg L−1(pH of 6). Langmuir isotherm best described theadsorption processwith a maximumadsorption capacity of 8.60mg g−1. Three kinetic models (apseudo-first-order, a pseudo-second-order (PSO) and Elovich) were also applied,and the results showed that the PSOmodel best described the data. SEM and EDAX analysis confirmed that P was adsorbed to the surface of the composite material. This study demonstrates that the composite adsorbent is suitable for use in wastewater treatment, with P removal of the solids being preferential and spontaneous.

scholarly journals Intensification of humic acid extraction from lignites

2020 ◽  
Vol 192 ◽  
pp. 02024
Author(s):  
Tatiana Moskalenko ◽  
Valery Mikheev ◽  
Elena Vorsina
Keyword(s):  
Humic Substances ◽  
Chemical Process ◽  
Raw Materials ◽  
Chemical Exposure ◽  
Materials Processing ◽  
Solid Fuels ◽  
Acid Extraction ◽  
Organic Mass ◽  
Chemical Reagents ◽  
Technological Mode

One of the methods of initial properties of solid fuels changing by their organic mass oxidation is considered in the paper. Creation of innovative ways of intensification of existing solid fuels processing and their adoption by industry has always been and remains an actual task. Thus the chemical process is the most important stage of raw materials processing into target products. Chemical exposure allows to optimize the technological mode, expanding the scope of control of technological process parameters and, to a certain extent, modify the properties of the resulting products. The article presents the results of experimental research of influence of preliminary oxidation on the lignite organic mass from Kharanorsk and Kangalas deposits by different chemical reagents to determine a degree of this process impact on the efficiency of their processing into humic substances. Inorganic and organic oxidizers of different concentrations were used as reagents. The greatest effect for increasing the humic acids yield was observed when using 6-10 % hydrogen peroxide for oxidation, and 10 % hydrochloric acid. The results of experiments on the coal preoxidation effect can be used as a basis for the development of a new method of lignites processing into humic substances.

The Pretreatment by the Fe/Cu Catalyzed Inner Electrolysis System for Enhancing Biodegradability of the Mixed Wastewater

2012 ◽  
Vol 610-613 ◽  
pp. 1368-1371
Author(s):  
Liang Sun ◽  
Gui Huan Yan ◽  
Chong Qing Xu ◽  
Dong Yan Guo ◽  
Yue Xia Lv ◽  
...  
Keyword(s):  
Biological Treatment ◽  
Loading Rate ◽  
Operating Cost ◽  
Reaction Times ◽  
Ecological Safety ◽  
Mass Ratio ◽  
Ph Range ◽  
Favorable Conditions ◽  
Electrolysis System

The Fe/Cu catalyzed inner electrolysis system was used to treat actual mixed wastewater to evaluate the ecological safety and feasibility of the technology. The pretreatment by the Fe/Cu process removed 30% of COD, which reduced the loading rate of the subsequent biological treatment. Meanwhile, BOD5/COD ratio was increased by about 160%, which created favorable conditions for the subsequent biological treatment. The results indicated that the optimal mass ratio of Fe and Cu was 4:1, the technology covered wider pH range: the wastewater responded well to the reduction when the influent pH changed from 4 to 8, the reaction times was 120 min. Furthermore, the consumption of iron was low. All these led to an easy maintenance and low operating cost.

Adsorption of mercury from aqueous solution by nontronite, Aspergillus niger, and hybrid material

2013 ◽  
Vol 48 (2) ◽  
pp. 155-170 ◽  
Author(s):  
Denis L. Guerra ◽  
Ricardo A. R. Silva ◽  
Ivani Mello
Keyword(s):  
Aqueous Solution ◽  
Aspergillus Niger ◽  
Equilibrium Constant ◽  
Liquid Interface ◽  
Natural Clay ◽  
Stirring Time ◽  
Ph Range ◽  
Solid Liquid Interface ◽  
Favorable Conditions ◽  
Solid Liquid

A natural nontronite clay sample from the Amazon region (Tocantins State, Serra da Messa Group, Brazil) was utilized for synthesis of a new biomaterial produced by a hybridization process of inorganic and organic materials. The new biomaterial was composed of an Amazon nontronite and fungal mass obtained from the Aspergillus niger fungus. The natural clay, biomass, and biomaterial samples were used in batch studies for adsorption of Hg2+ ions from aqueous solution. The effects of stirring time, adsorbent dosage, and pH on the adsorption capacity demonstrated that 70 min is sufficient to reach equilibrium at room temperature and over a pH range of 6.0–8.0. The maximum number of moles adsorbed was 9.47, 17.8, and 18.7 mmol g–1 for natural clay, biomass, and biomaterial, respectively. From the cation/basic center interactions for each material at the solid–liquid interface, by using calorimetry, the equilibrium constant and exothermic thermal effects were calculated. By considering the net interactive number of moles for mercury ion and the equilibrium constant, the enthalpy and negative Gibbs free energy could be calculated: ΔintH = −6.8 ± 0.11 to −6.0 ± 0.22 kJ mol–1; ΔintG = −20.5 ± 0.25 to −23.2 ± 0.22 kJ mol–1. The thermodynamic values indicated the existence of favorable conditions for interactions at the solid–liquid interface.

scholarly journals STATE AND TRENDS OF FOREST MANAGEMENT DEVELOPMENT

2021 ◽  
Author(s):  
Ella Dobrovolska ◽  
Nataliia Pokotylska
Keyword(s):  
Forest Management ◽  
Raw Materials ◽  
Radical Change ◽  
Forest Growth ◽  
Market Regulation ◽  
Resource Base ◽  
Current State ◽  
Natural Productivity ◽  
Favorable Conditions ◽  
Competitive Products

Market regulation, dissatisfaction with the real demand for timber and forestry products, subject to the full and efficient use of their own raw materials and, finally, entering the external market are impossible without a radical change in the structure of the economy as a whole and restructuring of production. This should ensure the production of competitive products, their compliance with export requirements, the creation of favorable conditions for investment, as well as for changing forms of ownership, makes us look for adequate approaches to structural transformations and fundamentally new elements of structural policy in relation to the forestry complex. The forestry of Ukraine is now characterized by a crisis situation: the state of forests does not meet economic and environmental requirements, the forest area has decreased more than three times over the last millennium, an anthropogenic reformation of forest landscapes has occurred, a decrease in their natural productivity, and a depletion of biodiversity. Forest stands are depleted by excessive felling, their natural protective functions are lower than potentially possible. Due to the lack of investments, the rates of reforestation and afforestation remain low, and the disparity between the forest resource base, opportunities for forest exploitation and forest consumption has deepened. In this regard, the study of the current state of development of enterprises will provide an opportunity to constantly monitor and determine the prospects for development of forestry. The article analyzes the current state and prospects for the development of forestry. The forest fund is characterized, the priority directions of the forestry enterprise development are given. Analyzed the main financial and economic indicators and indicators of forestry. The main problems of its functioning and the ways of their solution are given. It is emphasized that the current state of forests and forestry indicates an urgent need to develop new foundations of forest management, which would take into account the need for a diverse and targeted use of forests, increase their sustainability, as well as the active introduction of expanded reproduction of forest resources, intensification of forest growth.

scholarly journals NUTRITIONAL PROPERTIES OF CHIA SEEDS AND THEIR SANITARY SAFETY

2020 ◽  
Vol 14 (2) ◽  
Author(s):  
L. Valevskaya ◽  
A. Iegorova ◽  
L. Ovsiannykova ◽  
O. Sokolovskaya ◽  
F. Marchenkov ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Raw Materials ◽  
Living Organism ◽  
Peroxide Values ◽  
Chia Seed ◽  
Quality Of Food ◽  
Linolenic Fatty Acid ◽  
Unique Composition ◽  
Unique Chemical

Currently, there are more and more requirements not only to the quality of food, but also to the raw materials it is made from. This leads to the search for new, non-traditional products. One of these is chia seeds (Salvia hispanica). The article provides data on their useful properties. The high demand for chia seeds is due to their unique chemical composition. The main feature of the seeds of this crop is that they contain many chemical substances of high calorific and biological value, as compared with cereals and oilseeds traditionally grown in Ukraine. In chia seeds, there are 30–35% of fat, 25–41% of carbohydrates, and 20–22% of protein. Chia seeds are a valuable source of vitamin B, calcium, potassium, iron, zinc, and copper. The fatty acid composition of this crop indicates a high content of polyunsaturated fatty acids. 63.3% of them is linolenic fatty acid, which belongs to ω-3 acids and is important for the brain function, growth, and development of a living organism. That is why it is so important to find optimal ways of preparing freshly harvested chia seeds so as to extend their shelf life. These ways must take into account the biological and chemical characteristics of this crop, and make it possible to preserve its consumer properties for further targeted processing. The article presents the results of studying the quality indicators and microbiological condition of chia seeds to establish how long they can be safely stored and to assess the sanitary safety of this crop. It has been shown that within the period of 6 months, the greatest changes in the quality of chia seed oil are observed at 25°C: there is a significant increase in the acid and peroxide values and a decrease in the iodine value (the latter indicates spoilage of chia seeds). Lowering the air temperature to 5°C slows down the enzymatic processes that take place in chia seeds, and inhibits the increase of the acid and peroxide values of fat, which ensures retention of the consumer properties of seeds. It has been established that the seeds of the crop under study can be stored, without any loss of their quality, for 6 months at 5–15°C and the relative humidity 60–70%. All the beneficial properties of chia seeds are due to their unique composition, so they are supposed to be widely used for specialised and functional nutrition

Regional aspects of the development of light industry in Ukraine

2019 ◽  
pp. 64-73 ◽  
Author(s):  
Svitlana Ishchuk ◽  
Lyubomyr Sozanskyy
Keyword(s):  
Raw Materials ◽  
Light Industry ◽  
Textile Production ◽  
Synthetic Fibers ◽  
Agricultural Enterprises ◽  
Mountainous Regions ◽  
Industrial Parks ◽  
Priority Task ◽  
Favorable Conditions ◽  
Industrial Hemp

Light industry is one of the basic strategic segments of national economy, providing 5% of budget revenues and 2.6% of Ukrainian merchandise exports. The purpose of the article is to develop proposals to stimulate the development of light industry in Ukraine on the basis of an assessment of the dynamics of its performance at regional level in the context of main results of production and foreign economic activity. The results of the analysis of production activity in the light industry showed the relative stability of the structure of sales volumes in Ukraine, in which in 2018 clothing production accounted for 41.91%, textile production – 35.64% and leather production – 22.45%. The regional structure of domestic light industry remains little diversified. Export potential of light industry of Ukraine is mainly concentrated in two regions – Lviv (25.48%) and Transcarpathia (17.75%). The peculiarity of Ukrainian exports of light industry goods is the high proportion of finished goods made of toll materials. Hence, the priority task for ensuring the development of domestic light industry is to restore (with further increase) the raw materials production for textile and other industries in Ukraine. To solve this problem, it is necessary to create or modernize the facilities for processing wool, flax, industrial hemp, cotton, as well as for production of artificial and synthetic fibers that should be concentrated in regions with favorable conditions for their cultivation and harvesting. These are the mountainous regions of the Carpathians (wool production), as well as Ternopil, Volyn, Polissia, Kherson and others. The organizational form of implementation of such initiatives should be the creation of agro-industrial parks that operate based on the activities of large and medium-sized enterprises for production and processing of raw materials for needs of light industry. On the other hand, cooperation is a promising form of stimulating the development of small agricultural enterprises (small farmers or individuals).

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