scholarly journals Factors affecting bioleaching in the processing of non-metallics

2022 ◽  
Vol 7 (1) ◽  
pp. 11-16
Author(s):  
Iveta Štyriaková
Keyword(s):  
Magnetic Separation ◽  
Iron Removal ◽  
Raw Material ◽  
Bacterial Leaching ◽  
Iron Dissolution ◽  
Electromagnetic Separation ◽  
Factors Affecting ◽  
Fe Content ◽  
Quartz Sands ◽  
Physicochemical Factors

Biotechnological treatment of non-metallics is based on bacterial leaching of raw material and dissolution of Fe. Bacterial iron dissolution ability is dependent on various physicochemical factors as temperature, acidity of solutions, redox potential, rapidity of water circulation and presence of organic sources. The Fe content in the quartz sands and feldspar samples by the biological leaching decreased as much as 60% and by subsequent using of electromagnetic separation of feldspars, the decrease of Fe content in 74% was achieved. However, the application of magnetic separation of quartz sands after bioleaching resulted in total iron removal of 93% and in such combined way prepared product contained 0.024 % of Fe2O3. Achieved results on iron removal point to the fact that combination of leaching and magnetic separation enables to obtain product usable in glass and ceramic industry.

Biological Purification of Silicate Minerals

2007 ◽  
Vol 20-21 ◽  
pp. 126-129 ◽  
Author(s):  
Iveta Štyriaková ◽  
Michal Lovás
Keyword(s):  
Magnetic Separation ◽  
Heterotrophic Bacteria ◽  
Raw Materials ◽  
Iron Removal ◽  
Low Grade ◽  
Silicate Mineral ◽  
Iron Extraction ◽  
Fine Grained ◽  
Fe Content ◽  
Quartz Sands

Bioleaching is technology applicable to iron extraction from low-grade non-metallic raw materials. Bioleaching of quartz sands and feldspars involves the action of heterotrophic bacteria. Impurities include fine – grained limonite, goethite, hematite or mica were removed by the reductive dissolution of Fe3+ in linked with the silicate mineral destruction. Heterotrophic bacteria produced organic acids that are able to solubilize Fe oxide and silicates but require organic carbon as a source of energy. Molasses is a relatively inexpensive carbon source used for various industrial fermentations and contains also other nutrients that accounted for the enhancement of iron dissolution in this study. The admixture of pigments in molasses coloured the samples, but the discoloration could be removed by the addition of NaClO following the bioleaching step. The feasibility of the bioleaching treatment has to be tested specifically to each type of silicate raw materials. The Fe content in the quartz sands and feldspar samples by the biological leaching decreased as much as 60% and by subsequent using of electromagnetic separation of feldspars, the decrease of Fe content in 74% was achieved. However, the application of magnetic separation of quartz sands after bioleaching resulted in total iron removal of 93 % and in such combined way prepared product contained 0.024 % of Fe2O3. Achieved results on iron removal point to the fact that combination of leaching and magnetic separation enables to obtain product usable in glass and ceramic industry.

In Situ Application of Bioleaching for Improving the Quality of Quartz Sand

2009 ◽  
Vol 71-73 ◽  
pp. 497-500
Author(s):  
Iveta Štyriaková ◽  
Katarína Jablonovská ◽  
A. Mockovčiaková
Keyword(s):  
Environmental Conditions ◽  
Iron Dissolution ◽  
Bacterial Removal ◽  
Fe Content ◽  
Quartz Sands ◽  
In Situ Conditions ◽  
Basin Water ◽  
Fresh Surface

Quartz sands contain various iron and clay minerals which coat silicate grains or are impregnated in silicate matrix. Treatment by basin water bioleaching in combination with electromagnetic separation can substantially improve the quality of quartz sands. The purpose of this in-situ study was to evaluate the feasibility of using a biological basin treatment process to improve the quality of quartz sands. The environmental conditions involved the changes of climate temperature, using fresh surface water without disinfection, inhibition of algae and fungi, and promoting bacteria. Analyses of the solution phase were used to monitor the dissolution of iron during the bioleaching of the quartz sands and to optimize the in-situ conditions for the bacterial activity. The rate of iron dissolution varied with environmental conditions, with the addition of nitriloacetic acid (NTA)/l and organic feedstock in the form of molasses. Bacterial removal of clay and iron minerals can be used to expose the white surfaces of quartz grains. The quartz sands from the Šaštín deposit (Slovakia) were used in glass industry after decreasing the Fe content.

Factors Affecting Bioconcentration of Trace Organic Contamination in Waters

1989 ◽  
Vol 21 (2) ◽  
pp. 147-150 ◽  
Author(s):  
D. W. Hawker ◽  
D. W. Connell
Keyword(s):  
Molecular Weight ◽  
Bioconcentration Factor ◽  
Aqueous Solubility ◽  
Organic Chemicals ◽  
Organic Contamination ◽  
Hydrophobic Organic Chemicals ◽  
Factors Affecting ◽  
Water Partition Coefficient ◽  
Physicochemical Factors ◽  
Trace Organic

The influence of some important biological and physicochemical factors on the bioconcentration of hydrophobic organic chemicals is outlined. For non-ionizable, persistent compounds the bioconcentration factor can be related to a compound's octanol/water partition coefficient, aqueous solubility and molecular weight, while the lipid content of an organism also affects the bioconcentration potential of these compounds. The effect of ionization and biodegradation of organic chemicals on bioconcentration is also discussed.

scholarly journals High-Moisture Meat Analogues Produced from Yellow Pea and Faba Bean Protein Isolates/Concentrate: Effect of Raw Material Composition and Extrusion Parameters on Texture Properties

Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 843
Author(s):  
Ferawati Ferawati ◽  
Izalin Zahari ◽  
Malin Barman ◽  
Mohammed Hefni ◽  
Cecilia Ahlström ◽  
...  
Keyword(s):  
Faba Bean ◽  
Genetically Modified Organisms ◽  
Extrusion Process ◽  
Raw Material ◽  
High Moisture ◽  
Protein Isolates ◽  
Factors Affecting ◽  
Texture Properties ◽  
Meat Analogue ◽  
Bean Protein

Yellow pea and faba bean are potential candidates to replace soybean-based ingredients due to their suitability for cultivation in the northern hemisphere, non-genetically modified organisms cultivation practice and low risk of allergenicity. This study examined the functionality of local yellow pea and faba bean protein isolates/concentrate as meat analogue products. The most critical factors affecting the texture properties of meat analogue were also determined. Extrusion was used to produce high-moisture meat analogues (HMMAs) from yellow pea and faba bean protein isolates/concentrates and HMMAs with fibrous layered structures was successfully produced from both imported commercial and local sources. The texture properties of the HMMA produced were mainly affected by the ash, fiber and protein content and water-holding capacity of the source protein. Three extrusion process parameters (target moisture content, extrusion temperature, screw speed), also significantly affected HMMA texture. In conclusion, functional HMMA can be produced using protein isolates derived from locally grown pulses.

Consumer behaviour towards willingness to pay for Halal products

2019 ◽  
Vol 121 (2) ◽  
pp. 492-504 ◽  
Author(s):  
Waqar Ahmed ◽  
Arsalan Najmi ◽  
Hafiz Muhammad Faizan ◽  
Shaharyar Ahmed
Keyword(s):  
Willingness To Pay ◽  
Structural Equation ◽  
Quantitative Research ◽  
Reasoned Action ◽  
Raw Material ◽  
Equation Modeling ◽  
Muslim Country ◽  
Policy Makers ◽  
Content Type ◽  
Factors Affecting

PurposeThe purpose of this paper is to empirically analyze the factors affecting Muslim consumers’ willingness to pay (WTP) for Halal food, products and operations by employing theory of reasoned action.Design/methodology/approachThis study has used quantitative research methodology and collected data from 350 questionnaires from a densely populated city of Pakistan. Partial least squares-structural equation modeling was used to analyze the data.FindingsThe results show that the concerns about Halal, religiosity, perception of usefulness of Halal and product ingredients have a significant impact on WTP for Halal foods, while attitude has an insignificant impact on WTP. Moreover, the extent of demand for Halal certification is significantly affected by WTP.Originality/valueThe study highlighted the concerns of the Muslim consumers with respect to Halalness of the products and operations despite living in a Muslim country. It is recommended that the policy makers, food authorities and health institutions should conduct regular inspections of foods, products and producers’/manufacturers’ operations to ensure that all the procedures from manufacturing of the raw material till the finished goods follow Islamic principles to make them completely Halal.

scholarly journals Studies of factors affecting stability and efficiency of anion exchanger

2020 ◽  
Vol 177 ◽  
pp. 03020
Author(s):  
Nigora Mukhtarova ◽  
Bakhodir Aliev ◽  
Sadritdin Turabdzhanov ◽  
Latofat Rakhimova
Keyword(s):  
Ion Exchange ◽  
Anion Exchanger ◽  
Analytical Data ◽  
Polycondensation Reaction ◽  
Water And Wastewater Treatment ◽  
Factors Affecting ◽  
Exchange Processes ◽  
Physicochemical Factors ◽  
Swelling Capacity ◽  
Water And Wastewater

Various industries such as mining and the chemical industry are one of the most used ion exchange processes for water and wastewater treatment. The first section of this work presents the mechanism of the polycondensation reaction to obtain the polymer matrix of anion exchanger. Elemental analytical data conformed that anion exchanger holds 34,99% of nitrogen atoms and 44,47% oxygen atoms in the structure. In addition to the synthesis of the anion exchanger, physicochemical factors have a significant effect. The temperature of reactions for a certain time using a Lewis catalyst, the choice of the optimal solvent for improving swelling capacity of the starting monomers, due to their advantages as effective materials at a low price, are described in the second section. The information in the last section of the paper is devoted to the sorption properties and the ion-exchange processes in where the obtained anion exchanger was studied and used.

scholarly journals A study to set-up a technological process for purification of Zinc scraps by using liquation method

2021 ◽  
Vol 8 (1) ◽  
pp. 36-43
Author(s):  
Ngoc Vuong Tran ◽  
Manh Hung Luong ◽  
Dinh Dang Nguyen
Keyword(s):  
Zinc Oxide ◽  
Raw Materials ◽  
Time Factors ◽  
Pilot Scale ◽  
Raw Material ◽  
Optimal Time ◽  
Fe Content ◽  
Technology Process ◽  
Zn Content ◽  
Set Up

Zinc scrap is a source of raw material for zinc oxide production. However, to qualify the requirement of raw material for zinc oxide (99.5%) production, refining this source is needed. Many methods are considered such as rectification, chemical method, etc., but difficult to apply on an industrial scale. This workfocused on the investigation of the influence of temperature and time factors for asessing the possibility of applying liquation method for the purification of impurities from scrap zinc.The experiment results show that the optimum temperature of liquation to remove Pb,Fe from zinc scrap is in the range of 440-450°C, the optimal time of the process is 8h for the pot with 8cm in height and 6cm in diameter (the quantity of raw zinc sample is about 2kg / batch), then we can obtain about 80% of zinc metal with an average Zn content of about 97, 0%, both Pb and Fe content decreased to a range from 0.35 to 0.4%, and 1.0 to 1.1%, respectively, which meet the requirement of raw materials for the production of high quanlity ZnO ( 99,5 %). Based on the parameters obtained on lab-scale, a trial on pilot scale of 250 kg / batch was conducted, The result confirms that the quality of the products meets the requirement of raw materials for production of high quality ZnO (99.5%) and a technology process for refining zinc scrap by the liquation was proposed.

scholarly journals Issues in the Classification and Typology of Antique Masonry in the Writings of Foreign and Russian Scholars

2020 ◽  
pp. 1-14
Author(s):  
Andrei Grigorev
Keyword(s):  
Black Sea ◽  
Scientific Community ◽  
Raw Material ◽  
Historical Period ◽  
Military Architecture ◽  
Time And Space ◽  
Factors Affecting ◽  
Comprehensive Examination ◽  
Stone Carving ◽  
Scholarly Attention

The article examines the problems in developing approaches for the description and stylistic interpretation of antique masonry, as well as the issues in their stylistic dating. The task of dating construction remains belonging to the 7th century B.C.E. to the turn of the era, has attracted the scholarly attention of the scientific community since the 1940s and has been considered by both foreign and Russian researchers. The article's research object is the construction remains of Greek civil and military architecture in the Mediterranean and the Northern Black Sea regions - territories considered to have been the center and periphery of the Greek Oikumena. The study applied the comparative-typological method, the synchronization of objects in time and space, and dating by analogy. Both in Russian and foreign studies a significant amount of data has been collected for the analysis and construction of appropriate conclusions regarding the distribution and popularity of certain masonry in particular periods of time. However, due to the presence of many factors affecting the ancient construction and stone-carving craft, a number of exceptions due to local natural, economic, raw material, and administrative factors can be distinguished in the observed patterns. Thus, the whole picture of the formation of the construction and stone-carving craft (with the allocation of the corresponding types of masonry in a certain historical period) can be reconstructed only with a comprehensive examination of all of them. As the most interesting objects in this regard, the article cites a number of architectural remains belonging to the monuments of the distant chora of Tauric Chersonesos dating to the second half of the 4th century B.C.E.

scholarly journals The impact of globalization on the implementation of green purchasing in companies operating in the forest-based sector

2021 ◽  
Vol 129 ◽  
pp. 07005
Author(s):  
Nikola Slastanova ◽  
Marek Hlodak ◽  
Hubert Palus
Keyword(s):  
Value Added ◽  
Raw Material ◽  
Sustainable Competitive Advantage ◽  
Business Systems ◽  
Product Lines ◽  
Factors Affecting ◽  
Proactive Approach ◽  
Furniture Manufacturing ◽  
Green Purchasing ◽  
The Impact

Research background: The global environment influences the behaviour of companies. This concerns the requirements for increasing number of products, product lines, brands, the need for market segmentation, consumer demand, innovations as well as the behaviour of consumers and suppliers including environmentally appropriate purchasing. The forest-based industries must respond to changes from the perspective of the globalization process by appropriate adaptation and, inter alia, to focus on the introduction of environmentally properly procurement. The integration of green purchasing principles into business systems is increasingly mentioned in the process of globalization of economies in connection with the huge potential for gaining a sustainable competitive advantage. Purpose of the article: The aim of the paper is to identify and analyze the factors affecting the implementation of environmentally friendly purchasing in the companies of forest-based sector in Slovakia. Methods: The reasons for implementing responsible practices in supply chains are based either on the stakeholder theory or the assumption that companies have a more proactive approach to implement sustainable purchasing practices as they are aware of the possible benefits. Using a questionnaire survey the companies operating in all sub-sectors of the forest-based industry - wood, pulp and paper and furniture manufacturing, including their suppliers of wood raw material in Slovakia, were questioned with the aim to identify the reasons for implementing sustainable purchasing practices. Findings & Value added: Data obtained are used to identify the factors that are crucial for the introduction of green purchasing in companies in dependence on the specific company characteristics and conditions of the market environment under which companies operate.

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