Effective Removal of Ibuprofen from Aqueous Solution Using Cationic Surface-Active Agents in Dissolved Air-Flotation Process
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International Journal of Chemical Engineering publishes research focused on technologies for the production, processing, transportation and use of chemicals on an industrial scale.
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Chief Editor, Evangelos Tsotsas, holds the Chair of Thermal Process Engineering at Otto von Guericke University Magdeburg (Germany) since 1994. The main focus of his work is on drying, and on particle formulation processes related to drying, such as spray fluidized bed agglomeration.
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More articlesInvestigating the Adsorption of Humic Acid from Water Using CTS/PAM and CTS/PAM/EDTA Adsorbents
In recent decades, reports from around the globe indicate an increase in natural organic matters (NOMs) in surface waters, which has a negative impact on drinking water purification and causes problems such as the taste and color of water, reducing the amount of dissolved oxygen in water, causing membrane fouling in the filtration process, and acting as a precursor for the formation of an antiseptic by-product. This work used the adsorption process to evaluate the elimination of natural organic compounds in aquatic environments. Ethylenediaminetetraacetic acid (EDTA) as a crosslinker for chitosan (CTS) and N, N-methylenebisacrylamide as a crosslinker for polyacrylamide (PAM) were used to prepare humic acid (HA) adsorbents utilizing a two-step procedure. The FTIR spectroscopy proved the EDTA cross-linking agent was effective with the semicrosslinking CTS/PAM hydrogel. CTS/PAM/EDTA double network (DN) hydrogel exhibited a higher HA adsorption capacity ( = 107.7 mg/g) than CTS/PAM ( = 59.3 mg/g) at pH = 7 and an initial concentration of 60 mg·L−1 during 60 min. Also, results demonstrate that CTS/PAM/EDTA DN hydrogels showed faster adsorption kinetics than CTS/PAM.
Effect of inside Surface Baffle Conditions on Just Drawdown Impeller Rotational Speed
The effect of inside surface baffle installation conditions on the minimum impeller rotational speed for just the drawdown of floating solid was investigated. The inside surface baffle condition is the condition in which a partial baffle is placed with a clearance between the baffle and the vessel wall. In this study, a baffle with an insertion length of 0.2 times the liquid height was used. Moreover, the effect of baffle angle on was investigated. The was measured visually at least three times. The results showed that the effect of the radial installation position of the inside surface baffle on depended on the impeller position. In addition, even baffles placed parallel to the tangential flow were found to decrease .
A Study on the Valorization of Rice Straw into Different Value-Added Products and Biofuels
This work depicts that rice straw (RS), which is one of the major lignocellulosic wastes all over the world and causing many environmental problems, has considerable amounts of protein, ash, macronutrients, and micronutrients of approximately 11.38%, 16.77%, 2.27 mg/kg, and 771.9 mg/kg, respectively; besides, a C/N ratio of 15.18, a total N, P2O5, and K2O content of 1.85%, and a considerably low concentration of undesirable heavy metals and silica of approximately 77.69 mg/kg and 109 mg/kg are also present, which recommends its applicability as a precursor feedstock for the production of organic fertilizer and animal fodder. The batch solid-state fermentation (SSF) of RS by Trichoderma longibrachiatum DSMZ 16517 produced considerable amount of total reducing sugars (TRS) of approximately 339.2 mg TRS/g RS under the optimum operatic conditions of 20% (w:v) substrate concentration, pH 7, 1% inoculum size, a 9-day incubation period, and 30°C incubation temperature. The readily available and cost-effective agroindustrial waste, sugarcane molasses, proved to enhance the fungal biomass growth and (hemi) cellulolytic enzymes activities. The inoculated RS-SSF batch process with T. longibrachiatum precultured on 10% molasses enhanced the (hemi) cellulolytic enzymatic activities and TRS production rate by approximately 5.82 and 3.8 folds, respectively, relative to that inoculated by T. longibrachiatum precultured in the conventional potato dextrose broth medium. The separate hydrolysis and fermentation processes by different yeast strains Candida tropicalis DSM 70156, C. shehatae ATCC 58779, and Saccharomyces cerevisiae ATCC 64712 revealed an efficient bioethanol yield and productivity that ranged between 0.36 and 0.38 g/g sugars and 0.22 and 0.23 g/L/h, respectively, with concomitant competent fermentation efficiencies that ranged between 48.35% and 51.25%. The proximate analysis of rice straw before and after fungal hydrolysis proved calorific values of approximately 15.8 MJ/kg and 16.05 MJ/kg, respectively, recommending their applicability as primary and secondary solid biofuels. Thus, this study proved the waste prosperity of RS for environmental opulence and sustainability.
Numerical Study on Heat Transfer and Release Characteristics of Key Components in Electrically Heated Tobacco Products
Electrically heated tobacco products (EHTPs) could release effective aerosol components from tobacco materials at relatively low temperatures without a burning phenomenon. It is essential to grasp the temperature distribution and release mechanism of key components in heated tobacco materials. The existing experimental studies have provided initial insights into the thermodynamic behavior of tobacco materials under various conditions. However, current numerical models are still in their early stages of development, with the majority failing to correlate heat transfer with component release. Based on this, a coupled numerical model of gas flow, heat transfer, and the release of key components in the electrically heated tobacco product is established in this study, which exhibits improvements in revealing the internal heat and mass transfer characteristics in the porous media of tobacco and is capable of evaluating the influence of component contents and product design parameters. The release rates of water, glycerol, and nicotine components are quantitatively described by the first-order Arrhenius formula, and the transport of heat and gas flow is simulated using the Navier-Stokes equation. The accuracy of the model is validated through experiments, including temperature monitoring at multiple measurement points and determination of residual contents in the tobacco substrate after each puff. The simulation results suggest that an appropriate component ratio and tobacco filler mass can enhance both the release amount and release efficiency of key components, and reducing either the diameter or length of the tobacco section can help to improve the heat transfer performance. A slower heating rate matched with longer preheating times enables the complementary release of water and glycerol components, which helps to regulate the uniformity of component content in the aerosol to some extent. This study helps to provide suggestions for the design and optimization of electrically heated tobacco products.
A Retrospective Analysis of Polymer Selection Using Solvent Casting: Formulation and DoE Optimization of the Amorphous Solid Dispersion of Amoxicillin Trihydrate by a Spray Drying Method
Background. Amoxicillin trihydrate possesses poor solubility, compressibility, and flow behavior. Amorphous solid dispersion prepared by spray drying could solve all three problems at the same time. Objective. To prepare amorphous solid dispersion after screening of polymers by solvent casting method using a spray drying method. Methods. The solvent casting method was used to screen polymers, PVP/VA S-630, PVP K30, Soluplus, PEG 4000, HPMC AS, and HPMC HP55, in 1 : 1 and 2 : 3 ratios and followed by spray drying after polymer selection. Results. The dissolution performance of the formulation improved with time. The optimum feed rate and feed concentration were found to have an impact on the flow properties and particle size of spray-dried formulations, and they were selected as independent variables in a 32 full factorial statistical design. The ANOVA and regression analysis suggest that the developed regression model has a significant overall fit to the data and can explain a substantial proportion of the variability in the dissolution at 10 minutes. The optimized batch was selected based on the decisive factors of minimum and maximum values of response variables. Overall, the optimized batch demonstrated improved characteristics in terms of percentage yield (32.81%), dissolution at 10 min (49.70%), and angle of repose at 31.42°. Conclusion. This study provides valuable insights into optimizing formulation strategies for preserving the amorphous state of drugs and contributes to the development of stable pharmaceutical formulations.
Impact Evaluation of Wastewater Treatment Based on the Anaerobic Digestion of Sewage Sludge Using the Life Cycle Assessment Method
All the inputs and outputs of a technical system can be interpreted from an environmental point of view. Using the life cycle assessment (LCA) approach, some changes that are less harmful to the environment can be included in the system. This research aims to evaluate the environmental effects of the wastewater treatment plant (WWTP) in South Tehran, and the LCA method was used in this study. Based on the data of qualitative parameters obtained from the measurement of Tehran province’s water and sewage company, the environmental emissions were calculated and analyzed using SimaPro software (9.0.0) and the standards defined under the ReCiPe 2016-midpoint method. In the ReCiPe 2016 method, the results were expressed in two intermediate levels (including three classes of influence) and final (including 18). The results showed that the treated wastewater and chlorine factors had the most adverse environmental effects. Among the 18 effect classes, the treated wastewater in the class of marine environmental toxicity with the amount of 101.1531 kg 1,4-DCB had the most environmental impacts among other classes. The power consumed by the biogas-burning combined heat and power (CHP) unit in the wastewater treatment (WWT) process reduced the environmental effects in most impact classes. The most adverse environmental effects of the WWT process are related to damage to human health and the ecosystem. According to the findings, the use of CHP systems is suggested for energy saving and also for reducing harmful effects on the environment.