查看更多>>摘要：Chemicals injection for in-situ remediation of contaminated soils has attracted great attention. Efficiency of this technology relies on various parameters. Among them, chemical formulation of flushing agents has a key role. In this study, synergistic effect of Sodium Dodecyl Sulfate (SDS) ionic surfactant and Xanthan Gum (XG) biopolymer on the emulsification and solubilization of two types of petroleum hydrocarbon pollutants was investigated. Interfacial tension (IFT) measurements, bottle tests, droplet size distributions determination, and visual fluid flow experiments at pore-scale were conducted to assess pollutants removal strength of the proposed polymer enhanced surfactant flushing strategy. Results showed that although SDS surfactant reduced the equilibrium IFT of system to appropriate low value (i.e. less than 3 mN/m), it was not able to form stable oil-in-water emulsions. Nevertheless, addition of XG biopolymer, with no remarkable effect on IFT, improved emulsions formation and stability. Fluid flow experiments showed that oil snap-off and emulsion division are essential mechanisms of in-situ emulsion formation. A significant amount of hydrocarbon pollutants remained in porous medium after injection of 10 pore volumes of SDS. While, smaller size emulsions, as well as better contaminants removal were achieved for SDS solution with 4000 ppm XG at much lower injected pore volumes. (c) 2022 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.
查看更多>>摘要：With increasing urbanization and industrialization there is an upsurge in air pollution that demands immediate attention. The use of nanomaterials to alleviate air pollution is gaining importance. Certain nanomaterials can photocatalytically act on air pollutants such as oxides of nitrogen (NOx), sulfur (SOx), and carbon (CO2), thereby bringing down their concentration locally. Titanium Dioxide (TiO2), its composites, and TiO2 based Z/S scheme heterojunction photocatalysts are a few such nanomaterials. The band-gap of TiO2 in solid-state (3.2 eV) makes it a good photocatalyst in the ultraviolet region and its composites in the visible light region of the spectrum. Metropolitan cities are densely filled with high-rise buildings and the exteriors of these buildings, which are largely exposed to the atmosphere, can be utilized to coat these nano materials to enable photocatalytic reduction of air pollutants in the surrounding atmosphere. The nano photocatalysts can either be applied as coatings on the existing buildings or incorporated into the construction materials during construction. In this review article, an attempt is made to cover the application of photocatalysts in the construction industry starting from the working principle (mechanism) of heterogeneous and heterojunction photocatalysts, their advantages and disadvantages, methods of synthesis, pollution control applications, with emphasis on the methods of incorporating the photocatalysts into construction materials and also as a coating on existing buildings, the set up required to evaluate NOx reduction and the factors that affect the NOx reduction. The current status of pollution control applications in the construction industry and the authors perspective on the application of heterojunction photocatalysts in construction industry are highlighted. (C) 2022 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.
查看更多>>摘要：The effect of enzymes and other substances on gold bioleaching was investigated. Acinetobacter sp. had a higher gold leaching performance than two strains of Vibrio sp. because it grew well in nutrient broth (NB) medium containing potassium iodide (KI) and produced high levels of both laccase and triiodide (I3-). Under two-step condition of Acinetobacter sp. in NB medium containing KI 10.9 g.L-1 and 1% (w/v) alkali lignin had the highest efficiency in gold leaching. Plausible mechanisms of gold bioleaching involved in biogenic iodide-iodine lixiviant and laccase reaction mechanisms. Laccase produced by Acinetobacter sp. could directly oxidize insoluble gold to soluble gold and also increase iodide oxidation. Afterward, the gold can be oxidized completely in the biogenic iodide-iodine lixiviant to form gold (I) diiodide [AuI2]- or gold (III) tetraiodide [AuI4]-. Interestingly, it was found that silicate ore could act as an inducer of laccase production. Furthermore, alkali lignin addition could increase gold bioleaching due to it can be used as a substrate for laccase production. Therefore, the two-step condition of Acinetobacter sp. could be applied in gold leaching under mild alkaline pH conditions. The advantage of this technology was safer and more environmentally friendly than cyanidation as a conventional extraction.(C) 2022 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.
Thakur, AbhinayKaya, SavasAbousalem, A. S.Sharma, Shveta...
18页
查看更多>>摘要：The corrosion inhibition investigation of aerial extract of Cnicus Benedictus, a weed referring to the Asteraceae family has been evaluated on the mild steel corrosion in 0.5 M HCl with the employment of the weight-loss method, potentiodynamic polarization measurements (PDP) and electrochemical impedance spectroscopy (EIS) techniques. This investigation demonstrated Cnicus Benedictus extract (CBE) as a green and sustainable mild steel corrosion inhibitor in 0.5 M HCl media exhibiting an inhibition efficacy of 92.45% at 1000 ppm. With the increased concentration of CBE, the value of i(corr )and corrosion rate (C-R) decreased significantly from 7.4114 to 0.97438, revealing the protective effect of CBE on mild steel. The deposition of a highly defensive coating on the mild steel surface was demonstrated by the contact angle measurements. Additionally, the increase in the K(ads )values indicated a stronger interaction between the inhibitor molecules and metal surface. Furthermore, density functional theory (DFT) and Monte Carlo simulations have been utilized to validate the significant inhibition characteristic attained by the experimental study and to suggest an adsorption mechanism.(C) 2022 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.
查看更多>>摘要：Sewage sludge combustion experiments were carried out to investigate the migration and transformation of Zn, Mn, and Cr involved with the effects of combustion temperature, atmosphere, and steam concentration. The results showed that the volatilization of Zn was promoted by a temperature increase. Compared to air combustion, the inhibited volatilization of ZnCl2(g) and the production of ZnO promoted the recovery of Zn in ash during oxy-fuel combustion. Furthermore, the increasing temperature typically improved aluminosilicate capture MnO as well as the capability of CaO/Fe2O3 on capturing Cr. The reducing atmosphere caused by high CO2 concentration in oxy-fuel combustion facilitated the enrichment of Mn and Cr in ash. Steam favored the retention of Zn via transformation to form stable ZnO center dot A12O3 center dot 2SiO2 condensed into solid ash. The generation of CO and H2 from char-steam/char-CO2 gasification induced a local reducing atmosphere. It accelerated the transformation of MnO2 to MnO and facilitated the combination between MnO and aluminosilicate. Fe(III) reduced to Fe(II) strengthened the ability of iron oxide to capture Cr. The presence of steam promoted the decomposition of Ca-based minerals in the sewage sludge into a porous CaO, which enhanced the effect on Cr retention. (c) 2022 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.
查看更多>>摘要：To overcome the plasma system drawbacks, the hybrid system is used for the removal of pharmaceutical pollutants from effluents. In this study, the tetracycline (TC) removal from water was investigated using hybrid water falling film plasma-catalyst system. The ternary compounds nanocomposites containing zinc oxide (ZnO), nitride carbon graphite (g-C3N4), and zeolite with different ratios were synthesized at two stages using hydrothermal treatment method. Thereafter, the prepared nanocomposites were loaded on constructed plasma reactor equipped with the water falling film facility. The results of the characterization process confirmed that all synthesized nanocomposites had a suitable specific surface area, crystallinity, and the heterojunction formation ZnO with g-C3N4. The formation probability of S-scheme heterojunction structure of ZnO/g-C3N4 was discussed because of Fermi level's difference between ZnO and g-C3N4. Under the suitable operational condition, 95.5% TC removal efficiency as well as 4.43 synergistic effects were obtained using the hybrid system. The TC removal for hybrid system was ascribed as 30% more than sole plasma system. Afterward, the stability tests confirmed the ideal reusability of the prepared nanocomposite. The scavenger addition satisfied that the roles of both center dot OH and hole were critical. A mechanism was proposed for the TC degradation in this fabricated system. (c) 2022 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.
Chow, VinkyPhan, Raphael C-WLe Ngo, Anh CatKrishnasamy, Ganesh...
12页
查看更多>>摘要：Photocatalysis has emerged as a powerful technology with beneficial impacts on the fields of science and engineering. To date, most photocatalysis research are experimentally-based that strongly rely on various experimental conditions. As the coronavirus pandemic hit the world in 2020, research and experiments were disrupted in various scientific disciplines. During these unprecedented times, machine learning plays a vital role in the continuity of photocatalysis research, notably for researchers under physical access restrictions. More specifically, machine learning is capable of predicting the photocatalytic efficiency and analysing the photocatalytic activity. In recent work, it was demonstrated that a Support Vector Regression (SVR) model succeeded in predicting the efficiency of methyl tert-butyl ether (MTBE) photodegradation using titanium dioxide (TiO2) as a photocatalyst, achieving a Root Mean Square Error (RMSE) of 5%. In this work, we investigate the applicability of the Gaussian Process (GP) technique to predict the photodegradation efficiency of contaminants catalyzed by pure and doped-titanium dioxide (TiO2); and we compare their performance with the current state-of-the-art SVR. Within this context, we discuss the foundations of both the machine learning models, as well as demonstrate how photocatalysis researchers can apply them to solving relevant problems in the field of photocatalysis. (C)& nbsp;2022 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.
查看更多>>摘要：Hazardous materials (HazMat) transportation is one of the indispensable links in the chemical process industry and is closely related to safety, security, and environmental concerns. HazMat transportation routing is a major proactive risk management measure. Most related studies focus on diminishing the transportation risk for one single HazMat shipment. This work addresses a global perspective on the problem where the correlations of multiple simultaneous HazMat shipments are considered. A multi-objective transportation network design model is defined to optimize the objectives of the transportation risk and the transportation cost. A well-designed Pareto-based hybrid heuristic algorithm is proposed for model solving, which integrates a linear decomposition procedure for initial population construction, a Pareto-based scatter search procedure for population evolution, and a variable neighborhood search procedure for solution improvement. Computational results indicate that the proposed algorithm is competitive in solving large-scale instances since it is able to strike a great balance between effectiveness and efficiency. The detailed solution analysis shows that the proposed approach can effectively coordinate multiple simultaneous HazMat transportation processes. Moreover, we find that performing multiple short-distance shipments would significantly reduce the total transportation risk, but results in the higher transportation cost. This work can provide a set of Pareto optimal transportation networks for different industrial application scenarios to achieve the trade-off between economic and safety.(c) 2022 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.
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