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Showing records 3023 to 3047 of 3422. [First] Page: 1 118 119 120 121 122 123 124 125 126 Last
Renewable Hydrogen Production from Butanol Steam Reforming over Nickel Catalysts Promoted by Lanthanides
João Paulo da S. Q. Menezes, Gabriel M. Guimarães, Mônica A. P. da Silva, Mariana M. V. M. Souza
February 23, 2023 (v1)
Subject: Environment
Keywords: Butanol, coke, Hydrogen, lanthanides, reforming
Hydrogen is mainly produced by steam reforming of natural gas, a nonrenewable resource. Alternative and renewable routes for hydrogen production play an important role in reducing dependence on oil and minimizing the emission of greenhouse gases. In this work, butanol, a model compound of bio-oil, was employed for hydrogen production by steam reforming. The reaction was evaluated for 30 h in a tubular quartz reactor at 500 °C, atmospheric pressure, GHSV of 500,000 h−1, and an aqueous solution feed of 10% v/v butanol. For this reaction, catalysts with 20 wt.% NiO were prepared by wet impregnation using three supports: γ-alumina and alumina modified with 10 wt.% of cerium and lanthanum oxides. Both promoters increased the reduction degree of the catalysts and decreased catalyst acidity, which is closely related to coke formation and deactivation. Ni/La2O3−Al2O3 presented a higher nickel dispersion (14.6%) which, combined with other properties, led to a higher stability, higher mean hydro... [more]
Demulsification Treatment of Spent Metalworking Fluids by Metal Cations: The Synergistic Effect and Efficiency Evaluation
Yanqing Zhang, Lingxue Wu, Xiaochen Zhang, Baoxin Ge, Yuanfeng Qi
February 23, 2023 (v1)
Subject: Environment
Keywords: demulsification, efficiency evaluation, hazardous waste minimization, spent metalworking fluids, synergistic effect
In this paper, various metal ions were utilized for the demulsification of spent metalworking fluids discharged from an automobile parts workshop. Five types of metal ions, i.e., Fe3+, Al3+, Fe2+, Ca2+ and Mg2+, combined with coagulant were systematically evaluated, and the synergistic effect as well as the optimum operating conditions were studied. The results indicated that the Ca2+ as well Mg2+ possessed hardly efficiency for the demulsification, on the contrary, Fe2+ reduced the yield of the by-product sludge and lowered the SV30 ratio, and Al3+ boosted the CODCr removal. Furthermore, Fe3+ and Al3+ had a significant synergistic effect to achieve a better transmittance and a higher CODCr/SV30 ratio which revealed that more CODCr was removed, as well as less by-product sludge was generated. For a better demulsification of spent metalworking fluids, the optimum operating conditions were gathered as follows: the dosage of metal ions was 0.08 mol/L with Al3+:Fe3+ ratio was 1.5:1, the re... [more]
A Small-Scale Study on Removal of Heavy Metals from Contaminated Water Using Water Hyacinth
An The Huynh, Yi-Ching Chen, Bich Ngoc Thi Tran
February 23, 2023 (v1)
Subject: Environment
Keywords: arsenic, cadmium, copper, heavy metals, lead, water hyacinth, zinc
The aim of this research was to determine whether water hyacinth can be used to remove heavy metals, such as cadmium, arsenic, lead, zinc, and copper, from industrial wastewater. Investigations of the pollution removal or prevention potential of aquatic macrophytes, such as heavy metal bio-indicators in aquatic habitats, can prove to be advanced field studies. Water hyacinth is one of the aquatic plant species that has been effectively utilized for the treatment of wastewater. It is extremely effective in removing stains, suspended solids, BOD, organic matter, and heavy metals. This research focused on the use of water hyacinth to treat wastewater from heavy metals. Water hyacinths can grow in sewage, absorbing and digesting contaminants and transforming sewage effluents into comparatively clean water in the process. As a result, the plants have the potential to be used as natural water purification systems at a fraction of the cost of a standard sewage treatment facility. The experime... [more]
Composition of Oil after Hydrothermal Treatment of Cabonate-Siliceous and Carbonate Domanic Shale Rocks
Galina P. Kayukova, Zukhra R. Nasyrova, Anastasiya N. Mikhailova, Igor P. Kosachev, Firdavs A. Aliev, Alexey V. Vakhin
February 23, 2023 (v1)
Subject: Environment
Keywords: composition, Domanic rocks, hydrothermal processes, kerogen, mineral composition, organic matter, transformations
The hydrocarbon compositions of shale oils, generated from two different lithological−facial Domanic deposits of the Tatarstan Republic (Russia), were studied under hydrothermal impact with 30% of water addition in a 350 °С and CO2 environment. The samples were extracted from carbonate−siliceous rocks of the Semiluky−Mendym deposits of the Berezovskaya area, and carbonate deposits of the Dankovo−Lebedyan horizon of the Zelenogorskaya area of the Romashkino oil field. The distinctive features of rocks are in the composition and content of organic matter (OM), its thermal stability, as well as the structural-group composition of the shale oil products. The hydrothermal treatment of the rock samples increased the content of saturates and decreased the content of aromatics, resins and asphaltenes in the composition of crude oil. The decomposition of the polymer-like kerogen structure and destruction processes of high-molecular compounds, such as resins and asphaltenes, are accompanied with... [more]
To Advance Industrial Green Technology via Environmental Governance—Evidence from China’s Industrial Sector
Junwei Shi, Yingjing Yu
February 23, 2023 (v1)
Subject: Environment
Keywords: environmental regulation, governance synergy, industrial green technology progress, mediating effect
Industrial green technology progress is an effective way to realize high-quality economic development in China. The different competitive incentives of local governments make a difference in the intensity of environmental regulation between regions. The intensity of environmental regulation is different in different areas of the same industry, leading to the inter-regional transfer of pollution enterprises. The regional distribution of industries is different, which determines the different industries’ needs to coordinate different regions. Only when various industries realize the coordination of regional governance can they jointly promote the progress of industrial green technology. Based on data from 33 industrial sectors in China from 2001 to 2015 and considering the institutional evolution of governance synergy, this study comprehensively investigated the influence mechanism of local government environmental regulation on the industrial green technology progress using the mediatin... [more]
Environmental and Sustainability Analysis of a Supercritical Carbon Dioxide-Assisted Process for Pharmaceutical Applications
Paolo Trucillo, Roberta Campardelli, Iolanda De Marco
February 23, 2023 (v1)
Subject: Environment
Keywords: biomedical, liposomes, pharmaceutical applications, supercritical fluids
Drug delivery systems (DDS) are artificial devices employed to enhance drug bioavailability during administration to a human body. Among DDS, liposomes are spherical vesicles made of an aqueous core surrounded by phospholipids. Conventional production methods are characterized by several drawbacks; therefore, Supercritical assisted Liposome formation (SuperLip) has been developed to overcome these problems. Considering that the use of high pressures involves high energy cost, in this paper, sustainability indicators were calculated to quantitatively evaluate the emissions related to the attainment of liposomes containing daunorubicin (a model antibiotic drug) using the SuperLip process. The indicators were depicted using a spider diagram to raise the actual weaknesses of this technique; some variations were proposed in the process layout to solve the critical issues. According to the literature, many studies related to the pharmaceutical industry are expressed in terms of solid, liquid... [more]
Synthesis and Water Treatment Applications of Nanofibers by Electrospinning
Saumya Agrawal, Rashmi Ranjan, Bajrang Lal, Ashiqur Rahman, Swatantra P. Singh, Thinesh Selvaratnam, Tabish Nawaz
February 23, 2023 (v1)
Subject: Environment
Keywords: contaminants of emerging concern remediation, desalination, electrospinning, heavy-metal remediation, nanofiber
In the past few decades, the role of nanotechnology has expanded into environmental remediation applications. In this regard, nanofibers have been reported for various applications in water treatment and air filtration. Nanofibers are fibers of polymeric origin with diameters in the nanometer to submicron range. Electrospinning has been the most widely used method to synthesize nanofibers with tunable properties such as high specific surface area, uniform pore size, and controlled hydrophobicity. These properties of nanofibers make them highly sought after as adsorbents, photocatalysts, electrode materials, and membranes. In this review article, a basic description of the electrospinning process is presented. Subsequently, the role of different operating parameters in the electrospinning process and precursor polymeric solution is reviewed with respect to their influence on nanofiber properties. Three key areas of nanofiber application for water treatment (desalination, heavy-metal rem... [more]
Determination of Heavy Metal Contamination and Pollution Indices of Roadside Dust in Dhaka City, Bangladesh
Md Humayun Kabir, Md Harun Rashid, Qingyue Wang, Weiqian Wang, Senlin Lu, Shinichi Yonemochi
February 23, 2023 (v1)
Subject: Environment
Keywords: ecological risk, land-use category, pollution indices, seasonal variation, toxicity
Urban roadside dust samples from Dhaka City in Bangladesh were collected from a planned residential area (PRA), spontaneous residential area (SRA), commercial area (CA), and urban green area (UGA) in winter and summer to study how season and different urban land-use categories influence the concentrations of heavy metals (Cr, Mn, Co, Ni, Cu, Zn, As, and Pb) and different pollution indices. The dust samples were fractionated into <32 μm particles, extracted by acid digestion followed by estimation of heavy metals, using ICP-MS. Pollution indices were calculated from the metal concentrations, using standard protocols. The concentrations of heavy metals in roadside dust varied significantly (all p < 0.05), due to sampling seasons and the land-use category. Higher concentrations of heavy metals (Cr, Mn, Ni, Cu, Zn, and Pb) were found in the dust sampled during the winter season than in the summer season, except for As and Co. The geo-accumulation index (Igeo) indicated that the comme... [more]
Process Simulation and Life Cycle Assessment of Ceramic Pigment Production: A Case Study of Green Cr2O3
Olympios Alifieris, Dimitrios Katsourinis, Dimitrios Giannopoulos, Maria Founti
February 23, 2023 (v1)
Subject: Environment
Keywords: ceramic pigments, environmental impact, life cycle assessment
This study presents a combined process modeling—Life Cycle Assessment (LCA) approach for the evaluation of green Cr2O3 ceramic pigments production. Pigment production is associated with high calcination temperatures, achieved through the combustion of fossil fuels. Therefore, it is necessary to evaluate its environmental impact with regards to energy requirements and CO2 emissions. Initially, a process model is developed to simulate the final calcination stage of the traditional pigments production process. It is validated against titanium dioxide (TiO2) white production industrial data and adjusted for Cr2O3 production. Three alternative processes are examined: two for pigment grade (PIGM1, PIGM2) and one for metallurgical (MET) Cr2O3. Heat demand and CO2 emissions computed by the developed process models are used as input in the LCA along with upstream data from the literature using a cradle-to-gate approach. The implementation of the LCA has resulted in calculated Global Warming Pot... [more]
Dynamic Response Analysis of a Wavestar-Type Wave Energy Converter Using Augmented Formulation in Korean Nearshore Areas
Sanghwan Heo, Weoncheol Koo
February 23, 2023 (v1)
Subject: Environment
Keywords: augmented formulation, dynamic response, heaving point absorber, Korean nearshore area, wave energy converter, weakly nonlinear
Interest in water wave power generation, a promising source of renewable energy, is increasing. Numerous types of wave energy converters (WECs) have been designed to transform wave energy into electricity. In this study, we focus on heaving point absorbers (HPAs) of the Wavestar type, which consist of multiple floats connected to a bottom-fixed ocean structure by structural arms and hinges. Each float moves up and down due to wave forces and produces electricity using the hydraulic power take-off (PTO) system connected directly to the float. A numerical procedure using the three-dimensional augmented formulation was developed to calculate the rotational motion of the float. The frequency-dependent coefficients were calculated using the hydrodynamic solver WAMIT. The nonlinear Froude−Krylov and hydrostatic forces were considered. For the environmental conditions, the wave data of four nearshore areas in Korea, obtained from the Korea Meteorological Administration (KMA), were used. Under... [more]
The Influence of Variable CO2 Emission Tax Rate on Flexible Chemical Process Synthesis
Klavdija Zirngast, Zdravko Kravanja, Zorka Novak Pintarič
February 23, 2023 (v1)
Subject: Environment
Keywords: carbon tax rate, flexibility, greenhouse gas emission, MINLP process synthesis, stochastic two-stage with recourse
The emission of greenhouse gasses is a major environmental problem, and efforts are being made worldwide in various ways to encourage producers to reduce their emissions. There is a need to incorporate environmental measures into process design and synthesis, as pollution prevention is a higher priority than waste management, and in this way, more sustainable solutions can also be achieved. One possibility is to introduce a CO2 tax, the value of which is very uncertain in the future. This paper demonstrates how the CO2 tax affects the optimal results of synthesizing chemical processes using mixed-integer nonlinear programming (MINLP). It was found that the tax increase promotes the use of better-quality raw materials and more efficient process units. Energy consumption and emissions are reduced and economic performance deteriorates. A multi-period, two-stage stochastic approach with recourse is suitable to incorporate the uncertainty of the CO2 tax in the MINLP process synthesis and gi... [more]
Amino Acid-Based Natural Deep Eutectic Solvents for Extraction of Phenolic Compounds from Aqueous Environments
Meiyu Li, Yize Liu, Fanjie Hu, Hongwei Ren, Erhong Duan
February 23, 2023 (v1)
Subject: Environment
Keywords: amino acid, natural deep eutectic solvents, phenolic wastewater
The environmental pollution of phenol-containing wastewater is an urgent problem with industrial development. Natural deep eutectic solvents provide an environmentally friendly alternation for the solvent extraction of phenol. This study synthesized a series of natural deep eutectic solvents with L-proline and decanoic acid as precursors, characterized by in situ infrared spectrometry, Fourier transform infrared spectrometry, hydrogen nuclear magnetic resonance spectrometry, and differential thermogravimetric analysis. Natural deep eutectic solvents have good thermal stability. The high-efficiency extraction of phenol from wastewater by natural deep eutectic solvents was investigated under mild conditions. The effects of natural deep eutectic solvents, phenol concentration, reaction temperature, and reaction time on phenol extraction were studied. The optimized extraction conditions of phenol with L-prolin/decanoic acid were as follows: molar ratio, 4.2:1; reaction time, 60 min; and te... [more]
Influence of Maintenance Actions in the Drying Stage of a Paper Mill on CO2 Emissions
Luis Miguel Calvo, Rosario Domingo
February 23, 2023 (v1)
Subject: Environment
Keywords: CO2 emissions, industrial process, maintenance, papermaking
Greenhouse gases from industrial activities have become a global problem. Emissions management is being developed to raise awareness of the importance of controlling pollution in general and atmospheric emissions in particular. In 2017, the deficit of the rights of issuance in the industrial sectors increased up to 8.3% (verified emissions in 2017 versus allocation in 2017). This trend will increase more at the end of Phase III due to a progressive reduction in allocation. Phase IV will be much more restrictive in allocating emission rights than Phase III. The extra cost of this deficit reinforces the need for industry in general to reduce CO2 and for the paper industry to reduce GHG emissions and generate credits. Old factories are typically identified as sources of pollution in addition to being inefficient compared to new factories. This article discusses the possibilities offered by maintenance actions, whose integration into a process can successfully reduce the environmental impa... [more]
A Study on the Hydrolysis of Urea Contained in Wastewater and Continuous Recovery of Ammonia by an Enzymatic Membrane Reactor
Mukhtar Nuhu Yahya, Hüseyin Gökçekuş, Derin Orhon, Bülent Keskinler, Ahmet Karagunduz, Philip Isaac Omwene
February 23, 2023 (v1)
Subject: Environment
Keywords: continuous reactor, hydrolysis of urea, scanning electron microscopy, ultra-filtration, urea, urease
1. Background: Urea is the main product of the nitrogenous breakdown of protein metabolism in mammals. In this study, process intensification for enzymatic hydrolysis of urea by urease enzyme (jack bean urease) was examined in a membrane reactor. 2. Methods: Batch and continuous enzymatic hydrolysis reactions were performed at different substrate concentrations to determine the digestibility and affinity of the substrate with that of the enzyme. The hydrolysate samples were obtained by an optimized continuous enzyme membrane reactor (EMR) coupled with an ultra-filtration membrane (250 kDa). Feed concentration varied from 100 to 500 mg/L. Laboratory experiments were conducted at room temperature (20 ± 1 °C), with a flow rate of 20 mL/min, urease concentration of 0.067 g/L, ionic strength (I = 0, 0.01, 0.05), and ammonium nitrogen addition of (0, 100 mg/L, 200 mg/L, 500 mg/L). Moreover, the effect of ionic strength, ammonium nitrogen concentration, feed concentration, and enzyme concentr... [more]
Ecological Restoration of Wetland Polluted by Heavy Metals in Xiangtan Manganese Mine Area
Yang Lin, Yunan Jiao, Meifang Zhao, Guangjun Wang, Deming Wang, Wei Xiao, Huajun Li, Zhuo Xu, Yuqi Jiang
February 23, 2023 (v1)
Subject: Environment
Keywords: ecological interception system, ecological restoration, hyperaccumulator, wetland habitat, Xiangtan manganese ore
Due to manganese mining and slag accumulation, the geological structure of the wetland polluted by heavy metals in Xiangtan Manganese Mine area was seriously damaged, hence biodiversity loss, severe soil, and water pollution, as well as serious heavy metal pollution to food, vegetables, and other natural sources. In order to restore the ecological environment of the mining area, in 2015, the ecological restoration test of heavy metal polluted wetlands in the mining area was carried out. The results showed that the Mn content of different parts of Koelreuteria paniculata root from high to low order: fine root > small root > medium root > large root. The Mn content of different parts of Elaeocarpus decipiens root from high to low order: large root > medium root > small root > fine root. The order of Mn content in plants of the wetland restoration from high to low is as follows: Canna warscewiezii > Thalia dealbata > Boehmeria > Pontederia cordata > Typha orientalis > Nerium oleander > So... [more]
Air Pollution Analysis during the Lockdown on the City of Milan
Nicoletta Lotrecchiano, Paolo Trucillo, Diego Barletta, Massimo Poletto, Daniele Sofia
February 23, 2023 (v1)
Subject: Environment
Keywords: anthropic impact, atmospheric pollution, coronavirus, COVID-19, dynamic monitoring, lockdown, micro monitoring, pollution, saharan dust
From February 2020, the progressive adoption of measures to contain coronavirus’s contagion has resulted in a sudden change in anthropogenic activities in Italy, especially in Lombardy. From a scientific point of view, this situation represents a unique laboratory for understanding and predicting the consequences of specific measures aimed at improving air quality. In this work, the lockdown effect on Milan’s (Italy) air quality was analyzed. The PM10 and PM2.5 values were measured by the ARPA Lombardia, and the real-time on-road (ROM) air quality monitoring network indicates the seasonality of these pollutants, which typically record the highest values in the coldest months of the year. The 10-year particulate matter concentrations analysis shows a PM10 reduction of 35% from 2010 to 2020. March 2020 data analysis shows an alternation of days with higher and lower particulate matter concentrations; values decrease in pollutants concentrations of 16%, respective to 2018. The complexity... [more]
Jack Bean Development in Multimetal Contaminated Soil Amended with Coffee Waste-Derived Biochars
Ruan Carnier, Aline Renée Coscione, Douglas Delaqua, Aline Peregrina Puga, Cleide Aparecida de Abreu
February 23, 2023 (v1)
Subject: Environment
Keywords: biosorbents, coffee grounds, coffee parchment, mining soils, remediation, soil solution speciation
Coffee waste-derived biochar was found to immobilize heavy metals in contaminated soil, although there are few studies involving these materials. Given the large amount of waste generated in the coffee industry, this presents a relevant opportunity to contribute to the circular economy and environmental sustainability. Therefore, the objective of this study was to evaluate the effects of the application of biochars derived from coffee grounds and coffee parchment in the remediation of a Cd, Zn and Pb contaminated soil and at the development of jack beans (Canavalia ensiformis) in this area’s revegetation. The biochars were pyrolyzed at 700 °C, and the treatments were: contaminated soil (CT); contaminated soil + calcium carbonate (CaCO3); contaminated soil + 5% (weight (w)/weitght (w)) coffee ground biochar and contaminated soil + 5% (w/w) coffee parchment biochar. These treatments were incubated for 90 days, followed by the cultivation of jack beans for 60 days. Soil samples, soil solu... [more]
Environmental Performance of Road Asphalts Modified with End-of-Life Hard Plastics and Graphene: Strategies for Improving Sustainability
Massimo Perucca, Lucia Capuano, Giacomo Magatti, Francesca Rosa, Paride Mantecca
February 23, 2023 (v1)
Subject: Environment
Keywords: circular economy, end-of-life plastics, environmental performance, hard plastics, LCA, road pavement, Sustainability
Road construction takes a heavy toll on the environment. Therefore, innovative strategies to improve the environmental performances of this sector are needed, and the use of recycled materials (e.g., plastic) has been recently pursued to achieve this goal. The present work aims to (i) assess the environmental benefits deriving from the use of recycled hard plastics in combination with graphene to generate a new bitumen modifier and related asphalt mixture (AM) formulations (ii) to compare the performance of the bitumen modified using this new modifier with the bitumen modified using a traditional polymer (Styrene-Butadiene-Styrene, SBS) and the non-modified bitumen. A detailed Life Cycle Assessment (LCA) study was performed according to a cradle-to-cradle approach. Different scenarios were compared, including the variability of the pavement’s layers thickness and the amount of reclaimed asphalt pavement during the road maintenance cycles. The results demonstrated that the addition of t... [more]
Efficient Extraction of Methylene Blue from Aqueous Solution Using Phosphine-Based Deep Eutectic Solvents with Carboxylic Acid
Muhammad Faheem Hassan, Amir Sada Khan, Noor Akbar, Taleb Hassan Ibrahim, Mustafa I. Khamis, Fawwaz H. Jumean, Ruqaiyyah Siddiqui, Naveed Ahmed Khan, Nihal Yasir
February 23, 2023 (v1)
Subject: Environment
Keywords: deep eutectic solvent, extraction efficiency, ionic liquid, methyl orange, Wastewater
Methylene blue (MB), an organic thiazine dye, has numerous industrial and medical applications. However, MB is a wastewater contaminant that is harmful to humans and aquatic life. Hence, its removal from water bodies is essential. In this work, five novel deep eutectic solvents (DESs) were synthesized using different precursors, screened, and studied for the extraction of methylene blue (MB) from aqueous solution using liquid−liquid extraction. The first, TOP-SA, was synthesized using trioctylphosphine (TOP) as a hydrogen bond acceptor (HBA) and 2-hydroxy benzoic acid as a hydrogen bond donor (HBD). Among these, TOP-SA had the highest MB removal efficiency. The effects of pH, contact time, initial MB concentration, volumetric ratio, temperature, and ionic strength were studied and optimized. A 99.3% removal was achieved in 5 min for a 200 mg dm−3 MB solution mixed in a 1:10 ratio with TOP-SA at 25.0 °C. The structural properties of TOP-SA and its interactions with MB were investigated... [more]
Modeling and Analysis of Industry 4.0 Adoption Challenges in the Manufacturing Industry
Naif Alsaadi
February 23, 2023 (v1)
Subject: Environment
Keywords: challenges, Industry 4.0, manufacturing sector, structural model, sustainable development
The manufacturing sector is a fast-growing sector demanded by the increasing population. The adoption of information technology is a boon in the manufacturing industry. The industrial transformation from the third generation to the fourth generation has significantly impacted sustainable development. On account of this, different sectors are adopting industry 4.0 technologies to smooth their process flows. The industry 4.0 technologies implementation in the manufacturing sector will not only enhance its productivity, but also lead to sustainable growth. In this regard, this study intended to examine the challenges associated with adopting industry 4.0 technologies in the manufacturing sector. A thorough literature review was carried out from the Scopus database, and a list of ten important challenges was shortlisted for analysis. The article uses interpretive structural modeling to analyse the challenges of industry 4.0 and make a structural model between identified challenges. “Lack o... [more]
L-Glutathione-Functionalized Silica Adsorbent for the Removal of Pesticide Malathion from Aqueous Solutions
Sonia M. Vegas-Mendoza, José A. Gutierrez-Ortega, Rene G. Moran-Salazar, Sara A. Cortes-Llamas, Gregorio G. Carbajal-Arizaga, Alejandro A. Peregrina-Lucano, Ilya G. Shenderovich, Gabriela Torres-Santiago, Sergio Gómez-Salazar
February 23, 2023 (v1)
Subject: Environment
Keywords: Adsorption, amino acid, L-glutathione, malathion, pesticide removal, silica, Wastewater
An L-glutathione-functionalized silica adsorbent was applied in this study to remove malathion from aqueous media. This adsorbent has demonstrated an improved adsorption efficiency of malathion. The maximum uptake achieved was 130 mg g−1 at pH 8. Equilibrium was reached after about 90 min. A pseudo-second-order model best described the adsorption kinetics. The adsorption isotherms were best simulated by the Freundlich model. The functional groups are thermally stable up to about 150 °C. The elemental analysis results indicated high glutathione ligand densities. The results of this study show that the environmentally friendly L-glutathione functionalized silica is a promising candidate for the removal of malathion from water at the industrial level.
Photocatalytic and Electrochemical Activity of Magnesium Oxide Nanoballs Synthesized via a Hydrothermal Route
Suresh Sagadevan, J. Anita Lett, Is Fatimah, K. Tamizh Selvi, Ramesh Poonchi Sivasankaran, Getu Kassegn Weldegebrieal, Won-Chun Oh
February 23, 2023 (v1)
Subject: Environment
Keywords: and photocatalytic activity, electrochemical property, hydrothermal synthesis, MgO nanostructures, optical properties
Currently, there is growing concern about minimizing the environmental impacts caused by the generation of waste on water, soil, air pollution, and contamination of the environment in general. Magnesium oxide (MgO) nanoballs (NBs) were synthesized by the hydrothermal method followed by a calcination process. The average size of particles dispersed in deionized water was 159.2 ± 70 nm. The energy band gap was calculated to be 5.14 eV. The magnetic behavior, cyclic voltammetry, and electrochemical impedance of MgO NBs were studied. Under visible-light irradiation, the photocatalytic activity of MgO nanoballs was investigated by methylene blue (MB) dye. Results showed that photodegradation for MB under visible light irradiation for 120 min and degradation results are fitted well with pseudo-first-order reaction kinetics with a rate constant of 0.00252 min−1 and a correlation coefficient of 0.96.
Managing Transport Processes in Thermal Cracking to Produce High-Quality Fuel from Extra-Heavy Waste Crude Oil Using a Semi-Batch Reactor
Riyadh Almukhtar, Sally I. Hammoodi, Hasan Shakir Majdi, Khalid A. Sukkar
February 23, 2023 (v1)
Subject: Environment
Keywords: emergency pits, light fuel production, mass transfer, reaction mechanism, soil pollution, transport phenomena
Soil pollution from waste crude oil in emergency pits is a major problem at petroleum industry sites. In this work, extra-heavy waste crude oil was recovered from emergency pits and underwent many pre-purification processes to remove water and impurities. This type of oil was subjected to thermal cracking reactions in a semi-batch reactor constructed from stainless steel, with a volume of 500 mL. The cracking reactions were tested at operating temperatures of 400, 425, and 450 °C, with operating pressures of 1, 3, 5, and 7 bar. The results indicated that during thermal cracking, the reaction mechanism was highly dependent on the heat and mass transfer processes that occurred in the reactor. It was noted that the interaction between the optimal reaction temperature and operating pressure enhanced the product distribution and formation of high-quality liquid fuel with low gaseous and coke formations. The highest API of 30.5 was achieved for the liquid product at an operating temperature... [more]
Differential Response of Soil Microbial Community Structure in Coal Mining Areas during Different Ecological Restoration Processes
Yangnan Guo, Junlong Wu, Yan Yu
February 23, 2023 (v1)
Subject: Environment
Keywords: community structure, key bacterial group, mining areas, network analysis, soil remediation
Micro-organisms play important roles in promoting soil ecosystem restoration, but much of the current research has been limited to changes in microbial community structure in general, and little is known regarding the more sensitive and indicative microbial structures or the responses of microbial diversity to environmental change. In this study, based on high-throughput sequencing and molecular ecological network analyses, the structural characteristics of bacterial communities were investigated in response to four different ecological restoration modes in a coal mining subsidence area located in northwest China. The results showed that among soil nutrients, nitrate-nitrogen and fast-acting potassium were the most strongly associated with microbial community structure under different ecological restoration types. Proteobacteria, Actinobacteria, and Acidobacteria were identified as important phyla regarding network connectivity and structural composition. The central natural recovery z... [more]
Study of Technological Process of Fermentation of Molasses Vinasse in Biogas Plants
Waclaw Romaniuk, Ivan Rogovskii, Victor Polishchuk, Liudmyla Titova, Kinga Borek, Serhiy Shvorov, Kamil Roman, Oleksiy Solomka, Svetlana Tarasenko, Volodimir Didur, Victor Biletskii
February 23, 2023 (v1)
Subject: Environment
Keywords: biogas, biogas plant, cattle manure, Fermentation, methane fermentation, methane tank, vinasse
The volume of ethanol production waste—molasses waste in Ukraine—reaches up to 4 million m3 per year. It is not easy to dispose of and is polluting the environment. Currently, the development of an effective technology for using molasses in biogas plants to obtain energy gas—biogas—is an urgent problem. The purpose of our work is to determine the rational volume of loading molasses bard into the methane tank in a quasi-continuous mode to obtain the maximum volume of biogas. To achieve this goal, the following experimental studies were carried out: mono-fermentation of molasses and combined fermentation of cattle manure and molasses on a laboratory biogas plant in a periodic mode; on the basis of the obtained laboratory studies, a special simulation model of biogas output during the quasi-continuous fermentation of substrates was established and the amount of molasses added to obtain the maximum biogas output was determined. The maximum output of biogas under the periodic system of load... [more]
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