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Records Added in September 2021
Records added in September 2021
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Showing records 14 to 38 of 38. [First] Page: 1 2 Last
Plant-Based Tacca leontopetaloides Biopolymer Flocculant (TBPF) Produced High Removal of Heavy Metal Ions at Low Dosage
Nurul Shuhada Mohd Makhtar, Juferi Idris, Mohibah Musa, Yoshito Andou, Ku Halim Ku Hamid, Siti Wahidah Puasa
September 22, 2021 (v1)
Subject: Biosystems
Keywords: flocculation mechanism, heavy metal, hydroxide ion, polymer flocculant, Tacca leontopetaloides biopolymer flocculant (TBPF)
High removal of heavy metals using plant-based bioflocculant under low concentration is required due to its low cost, abundant source, and nontoxicity for improved wastewater management and utilization in the water industry. This paper presents a treatment of synthetic wastewater using plant-based Tacca leontopetaloides biopolymer flocculant (TBPF) without modification on its structural polymer chains. It produced a high removal of heavy metals (Zn, Pb, Ni, and Cd) at a low concentration of TBPF dosage. In our previous report, TBPF was characterized and successfully reduced the turbidity, total suspended solids, and color for leachate treatment; however, its effectiveness for heavy metal removal has not been reported. The removal of these heavy metals was performed using a standard jar test procedure at different pH values of synthetic wastewater and TBPF dosages. The effects of hydroxide ion, pH, initial TBPF concentration, initial metal ion concentration, and TBPF dosage were examine... [more]
Direct Growth of Carbon Nanotubes on Aluminum Foil by Atmospheric Pressure Microwave Plasma Chemical Vapor Deposition
Dashuai Li, Ling Tong
September 22, 2021 (v1)
Subject: Other
Keywords: aluminum foil, AMPCVD, CNTs, microwave plasma
This paper is about the research that carbon nanotubes (CNTs) grow on aluminum foils without additional catalysts by atmospheric pressure microwave plasma chemical vapor deposition (AMPCVD) with the precursor of argon-hydrogen-ethanol. At different temperatures, a series of experiments that CNTs grow on aluminum foils were done with and without the alumina layer. The EDS results showed that iron impurities in aluminum foils catalyze the growth of CNTs. By measurements of SEM and HRTEM, tens of microns long and multi-walled CNTs are grown. The CNTs’ content in the sample changes more with the increase in temperature. The Raman measuring shows that CNTs have fewer defects with higher temperature. Finally, by measurements of EDS mapping and XRD on aluminum foil, the growth mechanism of CNTs was discussed.
Experimental and Numerical Analysis of a Low Environmental Impact Pyro-Gasification System for the Energetic Valorization of Waste through a Biomass Steam Power Plant
Alfredo Gimelli, Massimiliano Muccillo, Raniero Sannino, Giacobbe Braccio, Vincenzo Capone, Giacinto Cornacchia, Matteo Manganiello, Carmine Mongiello, Vinod Kumar Sharma
September 22, 2021 (v1)
Keywords: biomass steam power plant, decision-making process, multi-objective optimization problem, pyro-gasification plant, thermochemical modeling
This paper addresses the study of a pyro-gasification plant designed, built, and operated to recover inert metals from different types of solid waste. Experimental tests were carried out using pulper as the solid waste. However, while a reliable composition analysis of the produced syngas was carried out, a precise composition evaluation of the pulper used during the experimental activities was not performed and the related data were characterized by unacceptable uncertainty. Therefore, with the aim of reliably characterizing the plant operation, a thermochemical model of the gasification process was setup to simulate the equilibrium operation of the plant and a vector optimization methodology was used to calibrate the numerical model. Then, a decision-making problem was solved to identify the most suitable optimal solution between those belonging to the Pareto optimal front, thus obtaining reliable composition data for the adopted pulper waste. In particular, four different identifica... [more]
Lumped Kinetic Modeling of Polypropylene and Polyethylene Co-Pyrolysis in Tubular Reactors
Andreas E. Lechleitner, Teresa Schubert, Wolfgang Hofer, Markus Lehner
September 22, 2021 (v1)
Keywords: feedstock recycling, kinetic modeling, lumped modeling, plastic pyrolysis, ReOil
The recycling rates, especially those from plastic packaging waste, have to be increased according to the European Union directive in the next years. Besides many other technologies, the pyrolysis of plastic wastes seems to be an efficient supplementary opportunity to treat mixed and unpurified plastic streams. For this reason, a pyrolysis process was developed for the chemical recycling of hydrocarbons from waste polyolefins. The obtained products can be further processed and upgraded in crude oil refineries, so that also monomers can be recovered, which are used for the plastic polymerization again. However, to achieve a scale up to a demo plant, a kinetic model for predicting the yields of the plastic pyrolysis in a tubular reactor is needed. For this reason, a pilot plant was built, in which different plastics and carrier fluids can be tested. Based on the data generated at the pilot plant, a very practical and suitable model was found to describe the plastic co-pyrolysis of the ca... [more]
Wheat Grinding Process with Low Moisture Content: A New Approach for Wholemeal Flour Production
Waleed H. Hassoon, Dariusz Dziki, Antoni Miś, Beata Biernacka
September 21, 2021 (v1)
Keywords: drying, grinding energy, particle size, wheat dough, wholemeal flour
The objective of this study was to determine the grinding characteristics of wheat with a low moisture content. Two kinds of wheat—soft spelt wheat and hard Khorasan wheat—were dried at 45 °C to reduce the moisture content from 12% to 5% (wet basis). Air drying at 45 °C and storage in a climatic chamber (45 °C, 10% relative humidity) were the methods used for grain dehydration. The grinding process was carried out using a knife mill. After grinding, the particle size distribution, average particle size and grinding energy indices were determined. In addition, the dough mixing properties of wholemeal flour dough were studied using a farinograph. It was observed that decreasing the moisture content in wheat grains from 12% to 5% made the grinding process more effective. As a result, the average particle size of the ground material was decreased. This effect was found in both soft and hard wheat. Importantly, lowering the grain moisture led to about a twofold decrease in the required grin... [more]
Tribological Properties of Additive Manufactured Materials for Energy Applications: A Review
Alessandro M. Ralls, Pankaj Kumar, Pradeep L. Menezes
September 21, 2021 (v1)
Subject: Materials
Keywords: additive manufacturing, energy applications, manufacturing, mechanical properties, metals, surface roughness, tribology
Recently, additive manufacturing (AM) has gained much traction due to its processing advantages over traditional manufacturing methods. However, there are limited studies which focus on process optimization for surface quality of AM materials, which can dictate mechanical, thermal, and tribological performance. For example, in heat-transfer applications, increased surface quality is advantageous for reducing wear rates of vibrating tubes as well as increasing the heat-transfer rates of contacting systems. Although many post-processing and in situ manufacturing techniques are used in conjunction with AM techniques to improve surface quality, these processes are costly and time-consuming compared to optimized processing techniques. With improved as-built surface quality, particles tend to be better fused, which allows for greater wear resistance from contacting tube surfaces. Additionally, improved surface quality can reduce the entropy and exergy generated from flowing fluids, in turn i... [more]
Torrefaction of Woody and Agricultural Biomass: Influence of the Presence of Water Vapor in the Gaseous Atmosphere
María González Martínez, Estéban Hélias, Gilles Ratel, Sébastien Thiéry, Thierry Melkior
September 21, 2021 (v1)
Keywords: Biomass, solid mass loss, TGA, torrefaction, water vapor
Biomass preheating in torrefaction at an industrial scale is possible through a direct contact with the hot gases released. However, their high water-content implies introducing moisture (around 20% v/v) in the torrefaction atmosphere, which may impact biomass thermochemical transformation. In this work, this situation was investigated for wheat straw, beech wood and pine forest residue in torrefaction in two complementary experimental devices. Firstly, experiments in chemical regime carried out in a thermogravimetric analyzer (TGA) showed that biomass degradation started from lower temperatures and was faster under a moist atmosphere (20% v/v water content) for all biomass samples. This suggests that moisture might promote biomass components’ degradation reactions from lower temperatures than those observed under a dry atmosphere. Furthermore, biomass inorganic composition might play a role in the extent of biomass degradation in torrefaction in the presence of moisture. Secondly, tor... [more]
Degradation of 2,4-Dichlorophenol by Ethylenediamine-N,N′-disuccinic Acid-Modified Photo-Fenton System: Effects of Chemical Compounds Present in Natural Waters
Wenyu Huang, Ying Huang, Shuangfei Wang, Hongfei Lin, Gilles Mailhot
September 21, 2021 (v1)
Subject: Other
Keywords: 2,4-DCP, EDDS, inorganic ions, natural water bodies, organic matter, photo-Fenton
This paper describes a study of the treatment of 2,4-dichlorophenol (2,4-DCP) with an ethylenediamine-N,N′-disuccinic-acid (EDDS)-modified photo-Fenton system in ultrapure water and different natural waters. The results showed that the EDDS-modified photo-Fenton system is adequate for 2,4-DCP degradation. Compared with a medium containing a single organic pollutant, the removal of pollutants in a more complex medium consisting of two organic compounds is slower by around 25 to 50% as a function of the organic pollutant. Moreover, 2,4-DCP can be further effectively degraded in the presence of organic materials and various inorganic ions. However, the photodegradation of 2,4-DCP in different natural waters, including natural lake water, effluent from domestic sewage treatment plants, and secondary effluent from pulp and paper mill wastewaters, is inhibited. Chemical compounds present in natural waters have different influences on the degradation of 2,4-DCP by adopting the EDDS-modified p... [more]
Adsorption of Tetracycline and Sulfadiazine onto Three Different Bioadsorbents in Binary Competitive Systems
Raquel Cela-Dablanca, Manuel Conde-Cid, Gustavo Ferreira-Coelho, Manuel Arias-Estévez, David Fernández-Calviño, Avelino Núñez-Delgado, María J. Fernández-Sanjurjo, Esperanza Álvarez-Rodríguez
September 21, 2021 (v1)
Subject: Biosystems
Keywords: antibiotics, competitive sorption, retention/release, sorbents
Different antibiotics contained in manure, slurry, wastewater or sewage sludge are spread into the environment. The harmful effects of these antibiotics could be minimized by means of immobilization onto bioadsorbent materials. This work investigates the competitive adsorption/desorption of tetracycline (TC) and sulfadiazine (SDZ) onto pine bark, oak ash and mussel shell. The study was carried out using batch-type experiments in binary systems (with both antibiotics present simultaneously), adding 5 equal concentrations of the antibiotics (between 1 and 50 µmol L−1). The adsorption percentages were higher for TC (close to 100% onto pine bark and oak ash, and between 40 and 85% onto mussel shell) than for SDZ (75−100% onto pine bark, and generally less than 10% on oak ash and mussel shell). Pine bark performed as the best adsorbent since TC adsorption remained close to 100% throughout the entire concentration range tested, while it was between 75 and 100% for SDZ. Desorption was always... [more]
Insights into Thermal Degradation Behaviors and Reaction Kinetics of Medical Waste Infusion Bag and Nasal Oxygen Cannula
Lifan Zhang, Jiajia Jiang, Tengkun Ma, Yong Pan, Yanjun Wang, Juncheng Jiang
September 21, 2021 (v1)
Keywords: activation energy, medical plastic waste, reaction mechanism, thermal degradation, thermogravimetric
The thermal degradation behaviors and reaction kinetics of medical waste infusion bag (IB) and nasal oxygen cannula (NOC) were investigated under inert atmosphere with the heating rates of 5, 10, 15, and 25 K·min−1. Ozawa−Flynn−Wall (OFW), Kissinger−Akahira−Sunose (KAS), and Friedman were employed to estimate the activation energy. Coats−Redfern and Kennedy−Clark methods were adopted to predict the possible reaction mechanism. The results suggested that the reaction mechanism of IB pyrolysis was zero-order, and that of NOC pyrolysis was concluded that zero-order for the first stage and three-dimensional diffusion Jander equation for the second stage. Based on the kinetic compensation effect, the reconstructed reaction models for IB and NOC pyrolysis were elaborated by introducing adjustment functions. The results indicated that the reconstructed model fitted well with the experimental data. The results are helpful as a reference and provide guidance for the determination of IB and NOC... [more]
Physico-Chemical and Pharmaco-Technical Characterization of Inclusion Complexes Formed by Rutoside with β-Cyclodextrin and Hydroxypropyl-β-Cyclodextrin Used to Develop Solid Dosage Forms
Teodora Balaci, Bruno Velescu, Oana Karampelas, Adina Magdalena Musuc, George Mihai Nițulescu, Emma Adriana Ozon, Georgiana Nițulescu, Cerasela Elena Gîrd, Catalina Fița, Dumitru Lupuliasa
September 21, 2021 (v1)
Subject: Biosystems
Keywords: antioxidant activity, hydroxypropyl-β-cyclodextrin, inclusion complexes, rutoside, β-cyclodextrin
The aim of our study was to obtain rutoside (RUT) inclusion complexes in β-cyclodextrin (β-CD) and in hydroxypropyl-β-cyclodextrin (HP-β-CD), in a 1:1 molar ratio, using the lyophilization method of complexation in solution. The complexes were confirmed and characterized, in comparison with the raw materials and their simple physical mixtures, by SEM, DSC, and FT-IR analyses. The antioxidant activity of the compounds was assessed by using the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) and 2’-azino-bis(3-ethylbenzothiazolin-6-sulfonic) acid (ABTS) radicals, determining the radical scavenging activity, and by ferric reducing antioxidant power (FRAP) assay. The results revealed superior antioxidant ability for the inclusion complexes towards rutoside alone. The inclusion complexes were used as active ingredients in formulations of immediate-release tablets. The preformulation studies were performed on the powders for direct compression obtained after mixing the active ingredients with the exci... [more]
Effect of Blanching on Enzyme Inactivation, Physicochemical Attributes and Antioxidant Capacity of Hot-Air Dried Pomegranate (Punica granatum L.) Arils (cv. Wonderful)
Adegoke Olusesan Adetoro, Umezuruike Linus Opara, Olaniyi Amos Fawole
September 21, 2021 (v1)
Keywords: antioxidants, colour, PCA, peroxidase, rehydration, texture
Blanch-assisted hot-air drying of pomegranate arils with blanching treatments 90 °C for 30 s, 100 °C for 60 s, and unblanched (control) arils were investigated. Effects of blanching on enzyme inactivation (polyphenol oxidase and peroxidse), colour, texture, and other qualities of dried arils were discussed. The hot-air drying conditions were 60 °C, 19.6% relative humidity, and 1.0 m s−1 air velocity. Results showed that blanching reduced enzyme activity by 76% and 68% for blanched arils treated at 90 °C for 30 s and 100 °C for 60 s, respectively, compared to unblanched arils. With regard to the total colour difference (TCD), unblanched arils were 20.9% and 16.6% higher than blanched arils treated at 90 °C for 30 s and 100 °C for 60 s, respectively. Furthermore, the total soluble solids (TSS) for unblanched aril increased significantly from 16.1 to 24.9 °Brix after drying, followed by arils treated at 90 °C for 30 s and 100 °C for 60 s (21.4; 18.5 °Brix), respectively. Among the blanchi... [more]
Effect of Ni(NO3)2 Pretreatment on the Pyrolysis of Organsolv Lignin Derived from Corncob Residue
Wenli Wang, Yichen Liu, Yue Wang, Longfei Liu, Changwei Hu
September 21, 2021 (v1)
Keywords: bio-oil, lignin, Ni(NO3)26H2O, pretreatment, pyrolysis
The thermal degradation of lignin for value-added fuels and chemicals is important for environment improvement and sustainable development. The impact of pretreatment and catalysis of Ni(NO3)2 on the pyrolysis behavior of organsolv lignin were studied in the present work. Samples were pyrolyzed at 500 ∘C with an upward fixed bed, and the characteristics of bio-oil were determined. After pretreatment by Ni(NO3)2, the yield of monophenols increased from 23.3 wt.% to 30.2 wt.% in “Ni-washed” and decreased slightly from 23.3 wt.% to 20.3 wt.% in “Ni-unwashed”. Meanwhile, the selective formation of vinyl-monophenols was promoted in “Ni-unwashed”, which indicated that the existence of nickel species promoted the dehydration of C-OH and breakage of C-C in pyrolysis. In comparison with “Water”, HHV of bio-oil derived from “Ni-unwashed” slightly increased from 27.94 mJ/kg to 28.46 mJ/kg, suggesting that the lowering of oxygen content in bio-oil is associated with improved quality. Furthermore,... [more]
Method and Device Based on Multiscan for Measuring the Geometric Parameters of Objects
Michael Yurievich Alies, Yuriy Konstantinovich Shelkovnikov, Milan Sága, Milan Vaško, Ivan Kuric, Evgeny Yurievich Shelkovnikov, Aleksandr Ivanovich Korshunov, Anastasia Alekseevna Meteleva
September 21, 2021 (v1)
Keywords: discrete–continuous structure, measurement, multiscan, photodiode cell, Vernier method, video signal
The article deals with the issues of improving the accuracy of measurements of the geometric parameters of objects by optoelectronic systems, based on a television multiscan. A mathematical model of a multiscan with scanistor activation is developed, expressions for its integral output current and video signal are obtained, and the mechanism of their formation is investigated. An expression for the video signal is obtained that reflects the dual nature of the discrete−continuous multiscan structure: the video signal can have a discrete (pulse) or analog (continuous) form, depending on the step voltage between the photodiode cells of the multiscan. A Vernier discrete−analog method for measuring the parameters of the light zone on a multiscan is proposed, in which in order to increase the accuracy of the measurements, the location of the video pulse is determined relative to the neighboring reference pulses of a rigid geometric raster due to the slope of the discrete structure of the mul... [more]
Microbial Production and Enzymatic Biosynthesis of γ-Aminobutyric Acid (GABA) Using Lactobacillus plantarum FNCC 260 Isolated from Indonesian Fermented Foods
Ida Bagus Agung Yogeswara, Suwapat Kittibunchakul, Endang Sutriswati Rahayu, Konrad J. Domig, Dietmar Haltrich, Thu Ha Nguyen
September 21, 2021 (v1)
Keywords: GABA, glutamate decarboxylase, Indonesian fermented foods, L. plantarum, lactic acid bacteria
In the present study, we isolated and screened thirty strains of GABA (γ-aminobutyric acid)-producing lactic acid bacteria (LAB) from traditional Indonesian fermented foods. Two strains were able to convert monosodium glutamate (MSG) to GABA after 24 h of cultivation at 37 °C based on thin layer chromatography (TLC) screening. Proteomic identification and 16S rDNA sequencing using MALDI-TOF MS identified the strain as Lactobacillus plantarum designated as L. plantarum FNCC 260 and FNCC 343. The highest yield of GABA production obtained from the fermentation of L. plantarum FNCC 260 was 809.2 mg/L of culture medium after 60 h of cultivation. The supplementation of 0.6 mM pyridoxal 5’-phosphate (PLP) and 0.1 mM pyridoxine led to the increase in GABA production to 945.3 mg/L and 969.5 mg/L, respectively. The highest GABA production of 1226.5 mg/L of the culture medium was obtained with 100 mM initial concentration of MSG added in the cultivation medium. The open reading frame (ORF) of 141... [more]
Advanced 3D Cell Culture Techniques in Micro-Bioreactors, Part II: Systems and Applications
Brigitte Altmann, Christoph Grün, Cordula Nies, Eric Gottwald
September 21, 2021 (v1)
Subject: Biosystems
Keywords: (hydro)gels, 3D cell culture, co-culture, flow, micro-bioreactor, multicellular aggregates, scaffold, simulations
In this second part of our systematic review on the research area of 3D cell culture in micro-bioreactors we give a detailed description of the published work with regard to the existing micro-bioreactor types and their applications, and highlight important results gathered with the respective systems. As an interesting detail, we found that micro-bioreactors have already been used in SARS-CoV research prior to the SARS-CoV2 pandemic. As our literature research revealed a variety of 3D cell culture configurations in the examined bioreactor systems, we defined in review part one “complexity levels” by means of the corresponding 3D cell culture techniques applied in the systems. The definition of the complexity is thereby based on the knowledge that the spatial distribution of cell-extracellular matrix interactions and the spatial distribution of homologous and heterologous cell−cell contacts play an important role in modulating cell functions. Because at least one of these parameters ca... [more]
Optimizing the Axial Resistance Profile of Submerged Hollow Fiber Membranes
Michael Kuhn, Heiko Briesen
September 21, 2021 (v1)
Subject: Other
Keywords: filter design, mechanistic model, membrane filtration, optimal control, process optimization
Submerged hollow fiber membranes (SHFMs) are used for a wide variety of applications. Their applicability and their advantages, however, depend crucially on the prevailing hydrodynamics within single fibers. In this respect, the non-uniform distribution of transmembrane flux is a known problem related to inhomogeneous membrane fouling and disadvantages for cleaning. To address this problem, we propose an approach to homogenize transmembrane flux by varying the local membrane resistance using optimal control methods for the first time in SHFM research. Based on an established model, different scenarios are optimized, namely with different fiber lengths and inner radii. In addition, a double-end setup is explored. It is shown that the optimization goal is reached very well in all tested cases, which underlines the general validity of our strategy. Further uses and extensions of the optimization method are provided, as well as hints for the practical implementation of the suggested measur... [more]
A Smart Production Process for the Optimum Energy Consumption with Maintenance Policy under a Supply Chain Management
Shaktipada Bhuniya, Sarla Pareek, Biswajit Sarkar, Bimal Kumar Sett
September 21, 2021 (v1)
Keywords: backorder, flexible production rate, maintenance, marketing, smart production, supply chain management
In the current socio-economic situation, smart products are essential for daily life. Energy is a very much related matter to smart products. To buy a smart product, people mostly care about that smart product’s energy consumption and the price. There is always a tug-of-war between the price of the product and the energy consumption of that product. An energy-efficient smart production system is described in this study where the production is variable, and in the out-of-control state, it produces defective products. For prevention of the out-of-control state, preventive maintenance and restoration are used within the smart production system. The rework policy helps to profit from the defective products, and the warranty policy helps to motivate the users. This model applies an improved strategy to the production process and develops a new product that needs to be marketed. Finally, this model plays a vital role in creating smart products with moderate energy consumption at a minimal co... [more]
Multi-Objective Coordinated Optimal Allocation of DG and EVCSs Based on the V2G Mode
Lijun Liu, Feng Xie, Zonglong Huang, Mengqi Wang
September 16, 2021 (v1)
Keywords: cluster dispatching, distributed power supply, EV charging station, peak and valley electricity prices, V2G mode
With the vigorous promotion of new energy sources and the development of vehicle-to-grid (V2G) technology, the influence of the V2G mode should be considered in the joint optimal allocation of Distributed Generation (DG) and electric vehicle charging stations (EVCSs). The timing characteristics of the intermittent output of DG, conventional demand for load, and charging load of the electric vehicle (EV) are considered, as is its participation in grid interaction to examine the construction of typical scenarios and the EV cluster dispatching strategy. From the perspective of comprehensively planning the coordination of the distribution network, a DG-EVCSs bi-level joint planning model is established under the peak and valley price mechanism, with the sub-objectives of obtaining a comprehensive profit and high quality of voltage, curbing system load fluctuations, and satisfactorily charging the EV. An improved harmony particle swarm optimization algorithm is proposed to solve the bi-leve... [more]
Modifying Effects of Physical Processes on Starch and Dietary Fiber Content of Foodstuffs
Róbert Nagy, Endre Máthé, János Csapó, Péter Sipos
September 16, 2021 (v1)
Keywords: dietary fibers, physical food processing, starch, technological properties of carbohydrates
Carbohydrates are one of the most important nutrients in human consumption. The digestible part of carbohydrates has a significant role in maintaining the energy status of the body and the non-digestible parts like dietary fibers have specific nutritional functions. One of the key issues of food processing is how to influence the technological and nutritional properties of carbohydrates to meet modern dietary requirements more effectively, considering particularly the trends in the behavior of people and food-related health issues. Physical processing methods have several advantages compared to the chemical methods, where chemical reagents, such as acids or enzymes, are used for the modification of components. Furthermore, in most cases, these is no need to apply them supplementarily in the technology, only a moderate modification of current technology can result in significant changes in dietary properties. This review summarizes the novel results about the nutritional and technologic... [more]
Comparative Analysis of the Behaviour of Marine Litter in Thermochemical Waste Treatment Processes
Johann Hee, Kai Schlögel, Simone Lechthaler, Jacqueline Plaster, Kristina Bitter, Lars Mathias Blank, Peter Quicker
September 16, 2021 (v1)
Subject: Materials
Keywords: biotechnological upcycling, gasification, incineration, marine litter, plastic waste, plastics recycling, pyrolysis, thermogravimetric analysis, waste treatment
Plastic in the ocean, especially plastic on the ocean surface is not only researched intensively but also photos and reports rise awareness of the challenge in the general public. While research is concerned with the fate of marine litter in the environment, recycling of these materials after collection is rarely addressed, mainly because there is neither considerable data on composition nor a suggested process to do so. This study is the first to analyse and evaluate chemical recycling (pyrolysis, gasification) and energy recovery (incineration) of marine litter. Two heterogenous marine litter samples from Sylt and Norderney, North Sea, Germany, were analysed, consisting of six different material groups. Agricultural mulch foil was used as reference material. The thermochemical treatment processes were reproduced by thermogravimetric analysis. Furthermore, pyrolysis trials on a semi-technical scale were conducted and the residues were analysed by proximate, ultimate and X-ray fluoresc... [more]
Alpha Amylase from Bacillus pacificus Associated with Brown Algae Turbinaria ornata: Cultural Conditions, Purification, and Biochemical Characterization
Mona Alonazi, Aida Karray, Ahmed Yacine Badjah-Hadj-Ahmed, Abir Ben Bacha
September 16, 2021 (v1)
Subject: Biosystems
Keywords: Bacillus pacificus, characterization, purification, α-amylase
We aimed in the current study, the identification of a marine bacterial amylase produced by Bacillus pacificus, which was associated with Turbinaria ornata. Cultural conditions were optimized for the highest amylase production on Tryptic soy broth media supplemented with starch 1% at initial pH 9, 55 °C for 24 h. The newly purified amylase was characterized for a possible biotechnological application. Data indicated that the obtained amylase with a molecular weight of 40 kD and the N-terminal sequence of the first 30 amino acids of amBp showed a high degree of homology with known alpha amylase, and was stable at 60 °C of pH 11. Among the tested substrate analogs, amBp was almost fully active on Alylose and Alylopectine (97%), but moderately hydrolyzed glycogen < sucrose < maltose < lactose. Therefore, the current amylase mainly generated maltohexaose from starch. Mg2+ and Zn2+ improved amylase activity up to 170%. While ethylenediamine tetraacetic acid (EDTA) similarly induced... [more]
Study on the Extraction Technology of Candida antarctica Lipase B by Foam Separation
Wenyao Shao, Ying Lin, Yinghua Lu
September 16, 2021 (v1)
Subject: Biosystems
Keywords: enrichment ratio, Fermentation, foam separation, lipase, recovery rate, surfactant
Candida antarctica Lipase B (CALB) has a wide range of applications in many fields. In this study, Pichia pastoris was used to express CALB for fermentation tank culture. Sodium dodecyl sulfate (SDS) was used as a surfactant, and foam separation technology was used to explore the best experimental conditions for the harvest of CALB. The results showed that the optimal technological conditions for the foam separation and recovery of CALB were as follows: liquid volume was 150 mL, separating gas velocity was 600 mL/min, pH value was 7, and surfactant SDS concentration was 0.5 mg/mL. Under these conditions, the enrichment ratio of CALB was 0.95, and recovery rate R was 80.32%, respectively, indicating that the foam separation technology is feasible to extract lipase B.
Ultrasonic Intensification of Mass Transfer in Organic Acid Extraction
Oleg M. Gradov, Yulia A. Zakhodyaeva, Inna V. Zinov’eva, Andrey A. Voshkin
September 16, 2021 (v1)
Subject: Other
Keywords: acoustics, aqueous two-phase system, eco-friendly extraction, intensification, interphase distribution, nonlinearity, poly (ethylene)glycol, pressure drop, resonance frequency, ultrasonic irradiation
The mechanism of ultrasonic extraction was discovered and analyzed in detail for the liquid membrane technique from the consideration of the specific features of the radial vibrations of a droplet of the dispersed phase placed into an immiscible continuous phase subjected to ultrasonic irradiation. Analytical formulas were derived for the rate of mass transfer as a function of the amplitude of acoustic pressure oscillations and the time of ultrasonic treatment of an extraction system. Conditions for achieving the maximum efficiency of the extraction of a substance under the stimulating effect of ultrasound were analyzed. A nonlinear equation was derived for the radial vibrations of a spherical droplet of the dispersed phase in an immiscible continuous phase under forcing in the form of acoustic pressure periodically changing with time. Experimental study of the dependence of sulfosalicylic acid distribution on time in an aqueous two-phase system with ultrasound shows good agreement of... [more]
Risk Assessment of Investments in Projects of Production of Raw Materials for Bioethanol
Anatoliy Tryhuba, Taras Hutsol, Inna Tryhuba, Nataliia Pokotylska, Nataliia Kovalenko, Sylwester Tabor, Dariusz Kwasniewski
September 16, 2021 (v1)
Keywords: bioethanol, investor, project, raw material production, risk
The proposed approach to quantitative assessment of the risk of investor’s profit in projects for the production of raw materials for bioethanol involves the implementation of eight stages. It systematically takes into account the stochastic nature of many factors that determine the amount of investments in the project, as well as the stochastic nature of the market value of raw materials. The use of the proposed approach makes it possible to obtain an accurate assessment of the level of risk of investors in projects for the production of raw materials for bioethanol, taking into account the requirements of investors. Based on the use of the developed application software, stochastic models of profit of investors in projects for the production of raw materials for wheat bioethanol and patterns of changes in their risk for the Western region of Ukraine are obtained. It is established that with the growth of the minimum expected profit of investors of projects from 10 to 70$/ton, the pro... [more]
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