Sonocrystallization of a novel ZIF/zeolite composite adsorbent with high chemical stability for removal of the pharmaceutical pollutant azithromycin from contaminated water.

Water pollution management, reduction, and elimination are critical challenges of the current era that threaten millions of lives. By spreading the coronavirus in December 2019, the use of antibiotics, such as azithromycin increased. This drug was not metabolized, and entered the surface waters. ZIF-8/Zeolit composite was made by the sonochemical method. Furthermore, the effect of pH, the regeneration of adsorbents, kinetics, isotherms, and thermodynamics were attended. The adsorption capacity of zeolite, ZIF-8, and the composite ZIF-8/Zeolite were 22.37, 235.3, and 131 mg/g, respectively. The adsorbent reaches the equilibrium in 60 min, and at pH = 8. The adsorption process was spontaneous, endothermic associated with increased entropy. The results of the experiment were analyzed using Langmuir isotherms and pseudo-second order kinetic models with a R2 of 0.99, and successfully removing the composite by 85% in 10 cycles. It indicated that the maximum amount of drug could be removed with a small amount of composite.

Knowledge Transfer in Support of the Development of Oxygen Concentrators in Emergency Settings During the COVID-19 Pandemic

The COVID-19 pandemic simultaneously disrupted supply chains and generated an urgent demand in medical infrastructure. Among personal protective equipment and ventilators, there was also an urgent demand for chemical oxygen. As devices to purify oxygen could not be manufactured and shipped rapidly enough, a simple and accessible oxygen concentrator based on pressure swing adsorption was developed at ETH Zurich in spring 2020. Instead of building devices locally and shipping them, it was decided to educate others in need of oxygen. The implementation encompassed education on process chemistry, material choice, and assembly and optimization of the concentrator and was realized using synchronous teaching tools, such as video call, and asynchronous ones, such as a website and video streaming. The project gained traction and interaction with engineering teams from universities and non-Governmental Organizations (Red Cross and the UN Development Program) in developing countries and emerging market economies, including Ecuador, Mexico, Somalia, and Peru. At the end of the project, the teams were surveyed regarding their experience in the educative knowledge transfer. It was reported that the learning experience prepared these groups well to build the device and to teach others as well. Major challenges were accessing some parts of the device and optimizing its performance. While synchronous communication is expected to be a very effective teaching method, the survey results showed that explanations via a website and video streaming have contributed the most to the implementation of the oxygen concentrator and thereby provide autonomous and sustainable education tools.

Recent trends in the nanozeolites-based oxygen concentrators and their application in respiratory disorders.

Medical-grade oxygen is the basic need for all medical complications, especially in respiratory-based discomforts. There was a drastic increase in the demand for medical-grade oxygen during the current pandemic. The non-availability of medical-grade oxygen led to several complications, including death. The oxygen concentrator was only the last hope for the patient during COVID-19 pandemic around the globe. The demands also are everlasting during other microbial respiratory infections. The yield of oxygen using conventional molecular zeolites in the traditional oxygen concentrator process is less than the yield noticed when its nano-form is used. Nanotechnology has enlightened hope for the efficient production of oxygen by such oxygen concentrators. Here in the current review work, the authors have highlighted the basic structural features of oxygen concentrators along with the current working principle. Besides, it has been tried to bridge the gap between conventional oxygen concentrators and advanced ones by using nanotechnology. Nanoparticles being usually within 100 nm in size have a high surface area to volume ratio, which makes them suitable adsorbents for oxygen. Here authors have suggested the use of nano zeolite in place of molecular zeolites in the oxygen concentrator for efficient delivery of oxygen by the oxygen concentrators.

ZEOLITE A/ZnCl2 NANOPARTICLES AS A CATALYST FOR ECO-FRIENDLY SYNTHESIS OF PYRAZOLE-1-CARBOTHIOAMIDES WITH DOCKING VALIDATION AS COVID-19 MAIN PROTEASE (MPRO) INHIBITOR

The synthesized Zeolite A/ZnCl2 nanoparticles via the hydrothermal route were characterized using FTIR, XRD, and SEM/EDAX techniques. The characterized catalyst was used for the eco-friendly synthesis of 4,5-dihydro-pyrazole-1-carbothioamide derivatives. Under solvent-free conditions, a multi-component reaction between hydrazine, isothiocyanate, and chalcone was done with a prepared nano-catalyst as an inexpensive, recyclable, easy-to-get, and nontoxic catalyst. The molecular docking study explained that dihydro-1carbothioamide pyrazoles can be considered COVID-19 main protease (Mpro) inhibitors. In order to investigate the 3D conformation of the compounds that were synthesized, the density functional theory (DFT) was applied with a B3LYP hybrid functional and a 6-311++ G(d,p) basis set. This allowed us to investigate the compounds' electronic and charge transfer properties. In this series of compounds, the derivative 30d showed the lowest HOMO–LUMO energy gap. © 2023 Chemical Society of Ethiopia and The Authors.

PRELIMINARY STUDY ON THE INFLUENCE OF THE USE OF VERMICOMPOST AS A CULTURE SUBSTRATE ON THE QUALITY OF LETTUCE SEEDLINGS (Lactuca sativa L.)

The experiment was carried out at the University of Agronomic Sciences and Veterinary Medicine of Bucharest, Faculty of Horticulture under laboratory conditions in 2020. During the COVID 19 pandemic, it took place in the university greenhouse, from the end of October until the end of November 2020. The biological material was represented by Red Oak lettuce cultivar, vermicompost (also known as vermicast), peat, zeolite and perlite. The paper aimed to present the benefices of using vermicompost in reducing nutrient solution and a higher yield. We tested 13 variants with 3 repetition each and used vermicompost in different percent as substrate such as 0%, 25%, 50% and 100% of pot volume. The vermicompost was produced by California Red Wigglers from converting two types of precomposted manure, horse and cattle over the period of 26 weeks. The vermicompost has a neutral PH 6.8-7.2 and does not burn the plant. The lettuce from variants where vermicompost was added, had a lower nutrient solution intake, this being an economic effect to reduce water consumption.

Thermo-Chemical conversion of polyolefin-based facemask using bench-scale pyrolysis system

The generation of personal protective equipment (PPE) waste due to the impact of COVID has increased multi-fold globally. In this study, pyrolysis of polyolefin-based PPEs was carried out using a bench-scale reactor of 2 kg per batch capacity. Thermogravimetric (TGA) analysis of face masks was carried out to identify the optimal parameters for the pyrolysis process. Different combinations of catalysts (ZSM-5 and montmorillonite), catalyst to feed ratio (2.5% and 5%), experiment duration (2 h and 3 h), and process temperature (450 degrees C and 510 degrees C) were tested to determine the maximum yield of the pyrolysis oil. The oil and char obtained from the pyrolysis of PPEs were analyzed for its gross calorific value (GCV), elemental analysis (CHNS), and chemical composition. Based on the experiments conducted, the optimum pyrolysis temperature, catalyst, catalyst to feed ratio, and batch time for maximum oil yield (55.9% w/w) were determined to be 510 degrees C, ZSM-5, 5%, and 2 hours, respectively. Oil was free of sulfur and had a calorific value of 43.7 MJ/kg, which is comparable to commercial diesel fuel and makes it a suitable alternative fuel for ships, boilers, and furnaces.

Zeolite and Activated Carbon as Catalysts on Leachate Clarification

Improper solid waste management worldwide has increased the negative impacts of landfills due to the production of methane, carbon dioxide, and leachate wastewater. In the present work, granular activated carbon (GAC), zeolite (Ze), and hydrogen peroxide were used for the purification of landfill leachate. Emphasis was given to decreasing operational costs for a big-scale advanced oxidation process. Thus, the aim was to evaluate the effect of oxidant and catalysts dosages, and different highly basic pHs. Up to 95% of dark brown colour and 100% of turbidity from landfill wastewater were removed. Based on the experimental findings, it is suggested that an application of activated carbon and hydrogen peroxide in a dosage ratio between 1.7 and 2.0 would be economically attractive in terms of reduced operation costs. © 2022, Kauno Technologijos Universitetas. All rights reserved.

An experimental study on modification of oxygen concentrator components for better purity

During the covid time, it was observed that the need for oxygen was very high, and this need was not achieved just by the oxygen cylinder. Ordinary people and hospitals started using oxygen concentrators to meet these needs. This paper focuses on improving the purity and the output flow rate of the oxygen concentrator. Different modifications were made by varying the number of air pores and filter count. Also, the compressor parameters like bore size, length, and flapper counts have been modified to increase the airflow concerning a liter per minute (LPM). The solenoid valve was configured to give maximum efficiency. Following the process, different Zeolite combinations were used to find the optimum purity of the oxygen concentrator. These modifications to the concentrator setup enabled 91.3% pure oxygen generation with an increase in the flow rate of the concentrator by 20%. © 2022 IEEE.

Transparent Anti-SARS COV-2 Film from Copper(I) Oxide Incorporated in Zeolite Nanoparticles.

The high antibacterial and antiviral performance of synthesized copper(I) oxide (Cu2O) incorporated in zeolite nanoparticles (Cu-Z) was determined. Various Cu contents (1-9 wt %) in solutions were loaded in the zeolite matrix under neutral conditions at room temperature. All synthesized Cu-Z nanoparticles showed high selectivity of the cuprous oxide, as confirmed by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analysis. An advantage of the prepared Cu-Z over the pristine Cu2O nanoparticles was its high thermal stability. The 7 and 9 wt % Cu contents (07Cu-Z and 09Cu-Z) exhibited the best activities to deactivate Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus bacteria. The film coated with 07Cu-Z nanoparticles also had high antiviral activities against porcine coronavirus (porcine epidemic diarrhea virus, PEDV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Specifically, the 07Cu-Z-coated film could reduce 99.93% of PEDV and 99.94% of SARS-CoV-2 viruses in 5 min of contact time, which were higher efficacies and faster than those of any previously reported works. The anti-SARS-CoV-2 virus film was coated on a low-cost PET or PVC film. A very small amount of cuprous oxide in zeolite was used to fabricate the antivirus film; therefore, the film was more transparent (79.4% transparency) than the cuprous oxide film or other commercial products. The toxicity of 07Cu-Z nanoparticles was determined by a toxicity test on zebrafish embryo and a skin irritation test to reconstruct a human epidermis (RhE) model. It was found that the impact on the aquatic environment and human skin was lower than that of the pristine Cu2O.

Therapeutic potential of cristobalite in the treatment of calf diarrhea.

Calf diarrhea continues to be the major problem of calves in the neonatal period. The effect of zeolites has been increasingly studied in ruminant health in recent years. In the present study, the efficacy of cristobalite, a zeolite, in neonatal calf diarrhea was studied first time. For this purpose, twenty-five neonatal calves with diarrheas were divided into two groups, and Group 1 (n=12) received conventional treatment and Group 2 (n=13) received cristobalite (Zoosorb 10 mg/kg) orally 3 times a day in addition to conventional treatment. Escherichia coli k99 and CS31a, bovine rotavirus and bovine coronavirus were isolated from fecal samples at the beginning of the treatment, on the third day and before discharge. It was determined that the recovery period in Group 2 was 0.95 (20.6%) days shorter than in Group 1 (p⟨0.05) while no viral agents were found on the fifth day in Group 2, viral shedding continued in 4 of 5 calves in Group 1. In conclusion, the study revealed that cristobalite speeds the recovery time and possibly decreases viral shedding in neonatal calf diarrhea, demonstrating a remarkable efficiency in the treatment.

The Diffusion Behavior of CO2 Adsorption from a CO2/N2 Gas Mixture on Zeolite 5A in a Fixed-Bed Column

The objective of this research was to investigate the behavior and conditions for CO2 adsorption using a mixture of CO2/N2 over a fixed-bed column of zeolite 5A. The study was performed with a variation in gas composition of CO2/N2 as a 20/80, 50/50, and 80/20 volume %, the adsorption temperatures as 298, 333, and 373 K and the total feed flow rates as 1, 2, and 4 L/h under 100 kPa pressure. The Bohart–Adams, Yoon–Nelson, and Thomas models were used to predict the breakthrough behavior of CO2 adsorption in a fixed column. Furthermore, the adsorption mechanism has been investigated using the kinetics adsorption of pseudo-first-order, pseudo-second-order, Boyd model, and intraparticle model. Increasing the CO2 composition of a gas mixture resulted in a high CO2 adsorption capacity because of the high partial pressure of CO2. The capacity of CO2 adsorption was decreased with increasing temperature because of physical adsorption with an exothermic reaction. The CO2 adsorption capacity was also decreased with increasing feed flow rates with inadequate time for CO2 adsorbates diffusion into the pores of the adsorbent before exiting the packed bed. The CO2 adsorption by zeolite 5A confirmed that the physical adsorption with intraparticle diffusion was the rate-controlling step of the whole process.

Pressure Swing Absorption Oxygen Concentrator equipped with Remote Monitoring Pulse Oximeter

The new COVID-19 disease was first identified in China at the end of 2019 and has spread rapidly all over the world. It has been projected that, by March 2021, the number of infections could reach 300 million cases and over two million deaths. One of the main implications for COVID-19 patients is pneumonia where the lung is infected, hence patients suffering from insufficient oxygen in the blood. As the number of COVID-19 cases have significantly increased, the demand for oxygen generators have also skyrocketed. This research concerns the design and construction of emergency low-cost oxygen concentrators used for mild COVID-19 symptoms, of which are forced to be treated at home. Our absorption-based oxygen concentrator uses zeolite packed in a sieve canister. An Oil-free compressor is then used to pump air in. Zeolite will absorb nitrogen from the air leaving oxygen free to travel towards the outlet. To evaluate the treatment, we have equipped the system with a pulse oximeter to measure the percent saturation oxygen, pulse rate and temperature. To prevent COVID-19 infections between patients and caretakers, we have designed an android application to remotely control the oxygen concentrator. Experiment has shown that our emergency low-cost oxygen concentrator can supply oxygen with an 85% purity rate. © 2021 IEEE.

A new strategy for butanol extraction from COVID-19 mask using catalytic pyrolysis process over ZSM-5 zeolite catalyst and its kinetic behaviour

This research aims to develop a new thermochemical strategy to extract butane from the billions of wasted Covid-19 masks that are generated every month. The experiments were conducted with 3-ply face masks (3PFM) over ZSM-5 zeolite with different ratios of ZSM-5 to 3PFM (w/w: 6, 12, 25, and 50 wt.%) using thermogravimetry (TGA) at different heating conditions. Also, the effect of ZSM-5 concentration and heating rates was examined using TG-FTIR and GC-MS measurements. Besides, the kinetics behaviour of the developed strategy was modelled using linear and nonlinear isoconversional modelling techniques, thus calculating the activation energy (Ea) for each conversion region. Finally, all required parameters to fit TGA and differential scanning calorimetry (DTG) experimental curves were estimated using the distributed activation energy (DAEM) and the independent parallel reactions (IPR) techniques, respectively. The results showed that the decomposed samples are very rich in aromatic and aliphatic (-C-H) compounds. Meanwhile, and based on GC-MS results, butanol compound was the basic component in the generated compounds with abundance of 31% at 25 wt.% of ZSM-5 at lowest heating rate (5 ˚C/min), whereas the average Ea at 25% of ZSM-5 (sample enriched with butanol) was estimated in the ranges 158-187 kJ mol−1 (linear methods with R2 > 0.96) and 167-169 kJ/mol (nonlinear methods with R2 > 0.98). Finally, DAEM and IPR succeeded to simulate TGA and DTG curves of ZSM-5/3PFM samples with very small deviation. Based on that, the catalytic pyrolysis strategy over ZSM-5 zeolite can be used effectively to dispose of Covid-19 masks and to convert them into butanol compound that can be used as a liquid fuel and lubricant.

Pectin-Zeolite-Based Wound Dressings with Controlled Albumin Release.

Hypoalbuminemia can lead to poor and delayed wound healing, while it is also associated with acute myocardial infarction, heart failure, malignancies, and COVID-19. In elective surgery, patients with low albumin have high risks of postoperative wound complications. Here, we propose a novel cost-effective wound dressing material based on low-methoxy pectin and NaA-zeolite particles with controlled albumin release properties. We focused on both albumin adsorption and release phenomena for wounds with excess exudate. Firstly, we investigated albumin dynamics and calculated electrostatic surfaces at experimental pH values in water by using molecular dynamics methods. Then, we studied in detail pectin-zeolite hydrogels with both adsorption and diffusion into membrane methods using different pH values and albumin concentrations. To understand if uploaded albumin molecules preserved their secondary conformation in different formulations, we monitored the effect of pH and albumin concentration on the conformational changes in albumin after it was released from the hydrogels by using CD-UV spectroscopy analyses. Our results indicate that at pH 6.4, BSA-containing films preserved the protein's folded structure while the protein was being released to the external buffer solutions. In vitro wound healing assay indicated that albumin-loaded hydrogels showed no toxic effects on the fibroblast cells.

Studies on the CO2 Capture by Coal Fly Ash Zeolites: Process Design and Simulation

At present, mitigating carbon emissions from energy production and industrial processes is more relevant than ever to limit climate change. The widespread implementation of carbon capture technologies requires the development of cost-effective and selective adsorbents with high CO2 capture capacity and low thermal recovery. Coal fly ash has been extensively studied as a raw material for the synthesis of low-cost zeolite-like adsorbents for CO2 capture. Laboratory tests for CO2 adsorption onto coal fly ash zeolites (CFAZ) reveal promising results, but detailed computational studies are required to clarify the applicability of these materials as CO2 adsorbents on a pilot and industrial scale. The present study provides results for the validation of a simulation model for the design of adsorption columns for CO2 capture on CFAZ based on the experimental equilibrium and dynamic adsorption on a laboratory scale. The simulations were performed using ProSim DAC dynamic adsorption software to study mass transfer and energy balance in the thermal swing adsorption mode and in the most widely operated adsorption unit configuration.

Kinetic Analysis for the Catalytic Pyrolysis of Polypropylene over Low Cost Mineral Catalysts

A kinetic analysis of non-catalytic pyrolysis (NCP) and catalytic pyrolysis (CP) of polypropylene (PP) with different catalysts was performed using thermogravimetric analysis (TGA) and kinetic models. Three kinds of low-cost natural catalysts were used to maximize the cost-effectiveness of the process: natural zeolite (NZ), bentonite, olivine, and a mesoporous catalyst, Al-MCM-41. The decomposition temperature of PP and apparent activation energy (Ea) were obtained from the TGA results at multiple heating rates, and a model-free kinetic analysis was performed using the Flynn–Wall–Ozawa model. TGA indicated that the maximum decomposition temperature (Tmax) of the PP was shifted from 464 °C to 347 °C with Al-MCM-41 and 348 °C with bentonite, largely due to their strong acidity and large pore size. Although olivine had a large pore size, the Tmax of PP was only shifted to 456 °C, because of its low acidity. The differential TG (DTG) curve of PP over NZ revealed a two-step mechanism. The Tmax of the first peak on the DTG curve of PP with NZ was 376 °C due to the high acidity of NZ. On the other hand, that of the second peak was higher (474 °C) than the non-catalytic reaction. The Ea values at each conversion were also decreased when using the catalysts, except olivine. At <0.5 conversion, the Ea obtained from the CP of PP with NZ was lower than that with the other catalysts: Al-MCM-41, bentonite, and olivine, in that order. The Ea for the CP of PP with NZ increased more rapidly, to 193 kJ/mol at 0.9 conversion, than the other catalysts.

Development and appraisal of handwash-wastewater treatment system for water recycling as a resilient response to COVID-19.

In this work, results from characterization of handwashing wastewater from selected stations in Kampala City, Uganda, revealed that handwashing wastewater did not meet permissible international standards for wastewater discharge to the environment. The ratio of BOD5 to COD of ˂ 0.5 implied that handwashing wastewater was not amenable to biological treatment processes. Turbidity of ˃ 50 NTU pointed to the need for a roughing filter prior to slow sand filtration. Subsequently, a handwashing wastewater treatment system consisting of selected particle sizes of silica sand, zeolite, and granular activated carbon as filtration and/or adsorption media was developed and assessed for performance towards amelioration of the physicochemical and biological parameters of the handwashing wastewater. Treated water from the developed wastewater treatment system exhibited a turbidity of 5 NTU, true color of 10 Pt-Co, apparent color of 6 Pt-Co, and TSS of 9 mgL-1, translating to removal efficiencies of up to 98.5%, 98.1%, 99.7%, and 96.9%, respectively. The residual total coliforms and E. coli of 1395 and 1180 CFU(100 mL)-1 respectively, were totally eliminated upon disinfection with 0.5 mL NaOCl (3.5% wt/vol) per liter of treated wastewater. The treated water was thus suitable for recycling for handwashing purpose as opposed to letting handwashing wastewater merely go down the drain. This approach provides a resilient response to COVID-19, where communities faced with water scarcity can treat and recycle handwashing wastewater at the point of washing. It thus enables more people to have the opportunity to practice handwashing, abating the high risks of infection, which could otherwise arise.