Applied Science and Engineering Progress

Biochar as a Catalyst in Biorefineries: A Sustainable Recovery of Waste Materials

Wed, 03 Apr 2024 00:00:00 +0700

Review on Advance Catalyst for Biomass Gasification

Wed, 03 Apr 2024 00:00:00 +0700

The production of renewable energy from biomass waste is a recent innovative approach attracting significant attention. In this field, gasification technology has become an important method, enabling the transformation of biomass into bio-syngas for wide applications, such as electrical power, transportation fuel, cooking fuel, and chemicals. Bio-syngas containing hydrogen, carbon monoxide, carbon dioxide, and methane, are considered a clean and nontoxic fuel. To achieve an effective and efficient gasification process, capable of producing a fuel grade syngas, the use of the catalyst has been reported as the most practical approach. Although this concept is currently in development, it has captured the interest of numerous investigations. The current challenge is the development of a catalyst that can reduce tar, enhance H2 yield at a relatively low temperature, capture CO2, and maintain an extended active lifespan. Therefore, this research aimed to review the novel catalysts discussed in the latest literatures with the ability to produce the highest hydrogen product by using an effective process. The catalysts included natural minerals containing alkali metals, metals, carbon, and composites. Additionally, here also suggested the potential materials should be explored more intensively for gasification catalysts. This review would help to promote and accelerate the research and application of biomass gasification using local existing feedstock. Since the future of energy depended on renewable sources, producing syngas became one of the best options to support energy demand using biomass waste in Indonesia.

Recent Updates on Jellyfish: Applications in Agro-based Biotechnology and Pharmaceutical Interests

Wed, 03 Apr 2024 00:00:00 +0700

Jellyfish are gelatinous sea creatures that belong to the subphylum Medusozoa of the phylum Cnidaria and are found on many beaches worldwide. Despite being considered a nuisance, jellyfish have many uses, such as being a source of high-value molecules such as collagen, gelatin, and protein hydrolysates and a source of high-protein food. Studies related to its availability, post-harvest applications, and need-based use in biomedicine are thrust research of analysis or investigation. Therefore, this review has been designed with all the latest information with a focus on applications of jellyfish in agro-based biotechnology and pharmaceutics. The review has been systematically arranged to present on the broader search platform for future research studies and possible need-based applications.

A Comparative Study of Different Materials for Manufacturing of Miniature Spur Gears by Spark Erosion Wire Cutting Process

Sujeet Kumar Chaubey, Kapil Gupta, Neelesh Kumar Jain — Wed, 03 Apr 2024 00:00:00 +0700

Selection of suitable materials plays a key role in machining to produce durable and good quality micro parts and components as well as improve the productivity of machining processes. This paper presents the performance evaluation of Spark Erosion Wire Cutting (SEWC) for the manufacturing of miniature gears from different materials, namely stainless steel SS 304, aluminum 7075, copper, and brass. The major objectives of this performance evaluation of SEWC are to determine the effect of gear materials on the quality of the gears, the economic aspects of miniature gears, and the productivity of SEWC for fabricating miniature spur gears. The optimal range of SEWC parameters from past research works was considered for conducting experiments for this study. Four miniature spur gears were fabricated from each gear material. It was concluded from this study that 1) the use of SS 304 as miniature spur gear material results in a better surface finish than aluminum, copper and brass; 2) use of aluminum as miniature gear material is more productive than SS 304, copper and brass; 3) aluminum is more economical and material-efficient than SS 304, copper and brass to fabricate miniature gears by SEWC; 4) material lost in copper is higher as compared to other selected materials; and 5) cost of SS 304 miniature gear is more as compared to other fabricated gears by SEWC.

Advancing the Performance of Ceramic - Reinforced Aluminum Hybrid Composites: A Comprehensive Review and Future Perspectives

Wed, 03 Apr 2024 00:00:00 +0700

Hybrid composites comprising aluminum reinforced with ceramics have surfaced as a potential class of materials that exhibit improved mechanical and thermal characteristics. These composites have a diverse range of applications across multiple industries. The present study offers a thorough examination of recent scholarly investigations pertaining to such composites, with particular emphasis on their mechanical performance, thermal attributes, and interfacial characteristics. This paper offers an extensive evaluation of ceramic-reinforced aluminum composites, along with a discussion of potential solutions and prospects for addressing the existing limitations and challenges. This review explores emerging areas of research, encompassing interface engineering methodologies, sophisticated processing techniques, and the incorporation of innovative reinforcement substances. The present recommendations are geared towards augmenting the efficacy, dependability, and durability of hybrid composites comprising ceramic and aluminum reinforcements.

Advantages of Electro-deposited Gold on Carbon Electrodes for NT-proBNP Immunosensor for Development of Heart Failure Test Kit

Wed, 03 Apr 2024 00:00:00 +0700

Accurate measurement of the N-terminal pro B-type natriuretic peptide (NT-proBNP) in serum is important for the diagnosis of heart failure (HF). Carbon screen-printed electrodes (SPCEs) modified with graphene oxide (GO) or gold (Au) were compared for the construction of NT-proBNP immunosensors. NT-proBNP and its recognition unit, a single-chain variable fragment fused with alkaline phosphatase (scFv-AP), were expressed and purified. The currents of the electrodes immobilized with scFv-AP were measured after adding an ethanolamine (ETA), blank and NT-proBNP in either phosphate buffer saline (PBS) or human serum. SPCE/Au had lower mean baseline slopes than for SPCE/GO for all measurements, in both PBS and serum, indicating greater accuracy for SPCE/Au. None of the measurements in PBS had statistically different peak currents between SPCE/GO and SPCE/Au; however, there was a significant difference with the serum. The significant reduction of SPCE/ GO peak currents after applying serum blank implied non-specific absorption on the surface. The peak current of 300 pg/mL of NT-proBNP in the serum measured on SPCE/Au was significantly higher (by a factor of three) than on SPCE/GO, suggesting the possibility of using SPCE/Au to detect NT-proBNP at higher concentrations. The binding efficiency of scFv-AP to NT-proBNP did not depend on the electrodes, as shown by the similar delta peak-currents (Blank-Target). Thus, immobilized scFv-AP on SPCE/Au electrodes had good potential to accurately detect NT-proBNP in serum, for use in the fabrication of an HF test kit.

Combustion Assisted Synthesis of CuO Nanoparticles and Structure-Property Evaluation in nano-CuO Polymer Composites

Gopinath Prasanth, Gattumane Motappa Madhu, Nagaraju Kottam — Wed, 03 Apr 2024 00:00:00 +0700

Metal oxide-based nanoparticle as a filler in epoxy polymer composites has diverse applications in various industries, including adhesives, automobiles, aerospace, wind energy, and civil engineering. However, these composites must fulfill essential properties encompassing chemical, curing, optical, and thermal attributes. This study focuses on enhancing epoxy polymer by integrating copper oxide (CuO) nanoparticles synthesized through solution combustion. Varied CuO loadings (0.5–2.5 wt.%) were impregnated into the epoxy, critically impacting the structural attributes of the resulting nano-CuO polymer composites. Various material characterization techniques were employed to study the synthesized materials' morphology, elemental composition, phase formation, identification of the presence of functional groups, thermal stability, and optical properties. SEM images show the presence of spherical particles with porous structures. EDX confirmed the presence of Cu and O elements, while the XRD pattern showed the formation of CuO with an average crystallite size of 46 nm. FTIR confirms the presence of O-H, C-H, and C=C functional groups. TGA showed thermal stability and revealed minimal mass loss below 250 °C for nano-CuO polymer composites and minimal mass loss occurred for CuO nanoparticles at 900 °C. Photoluminescence exhibited redshifted luminescence spectra. The study suggests improved qualities due to CuO nanoparticle integration into epoxy. CuO loading crucially influences nano-CuO polymer composite properties, rendering them ideal for high-temperature applications, supported by remarkable thermal stability evidenced by substantial residual mass in TGA.

Developing and Implementing a Quantum Algorithm for the Sliding Mode Controller Using Multiple Qubit Operators: Application to DC Motor Speed Drive

Nadjet Zioui, Aicha Mahmoudi, Mohamed Tadjine — Wed, 03 Apr 2024 00:00:00 +0700

With the advent of quantum computing, almost all classical computing concepts must be translated into quantum equivalents. Control theory, in particular, requires a large numbers of calculations. This paper designs and presents a quantum sliding mode controller. The controller uses two qubit states, one for detecting tracking errors and the other for determining the signs of the errors. The control signal to be applied to the system is stored in the third qubit state. This new controller is implemented on a DC motor to control the angular velocity using electrical current as an input signal. In terms of tracking error energy performance, the results show that the quantum sliding mode controller is just as efficient as the classical sliding mode controller. However, the quantum controller outperforms its predecessor by using 76% to 79% less control energy, allowing for smaller actuators. This represents a significant advancement in control theory in the era of quantum computers. Indeed, actuator control energy is the main drawback of the classical sliding mode control and reducing this energy is one of the main challenges for the control community.

Development of Screw-Based 3D Printing Machine and Process Experiments for Short Fiber Reinforced Polymer Composites

Thanapat Sangkharat, Laongdaw Techawinyutham — Wed, 03 Apr 2024 00:00:00 +0700

3D printing is one of the flexible additive manufacturing (AM) processes that can be used to fabricate parts from various types of materials such as polymers, metal, and ceramic. 3D printing process is one of the famous techniques for printing the product from the filament causing material degradation. Granule-based 3D printing or screw-based material extrusion 3D printing is an alternative process that can create the parts from plastic or composite granule raw materials. However, there are limited use and study in the designation of granule-based 3D printing and process parameters including material temperature, heat bed temperature, nozzle size, and printing speed. These process parameters play a significant role in the properties of 3D printing parts. Some parameters cannot be adjusted in the commercial 3D printing process. Thus, the purposes of this study are to develop a screw-based material extrusion 3D printing machine that can freely adjust the process parameters and to investigate the effect of 3D printing parameters on the appearance and mechanical properties of printed parts. Pellets of neat acrylonitrile butadiene styrene (ABS) and short glass fiber/ABS composites are used in the experiments. Six process parameters were studied, including % fiberglass, printing temperature, printing speed, nozzle size, % Infill, and heat bed temperature. Each parameter has 3 levels, which were designed by the Taguchi L18 method. The results were evaluated by the main effect plot method and showed that the printing speed, nozzle size, and %fiberglass are the top 3 parameters that affect tensile strength. The nozzle size, %infill, and %fiberglass are the top 3 parameters that affect Young’s modulus. The granule-based 3D printing machine was completely developed; however, the extruded plastic line from the nozzle was difficult to control resulting in poor product quality. Thus, the feedback control for controlling the screw-extruder speed and temperature will be developed in future work.

Diversity of Anammox Bacteria from Landfill Treatment Plant Sludge in Tropical Area

Wed, 03 Apr 2024 00:00:00 +0700

The anaerobic ammonium oxidation (anammox) process is known as the warm process. Tropical areas have an advantage due to their consistent temperature throughout the year. This study analyzed the diversity of anammox bacteria in the tropical area using leachate sludge from a landfill as an inoculum in a filter bioreactor (FtBR) and observed nitrogen removal performance. Ammonium and nitrite concentrations of 70, 150, and 200 mg-N/L were delivered into the reactor continuously with hydraulic retention time (HRT) of 24 h and 12 h and run for 131 days at ambient tropical temperature (25–28 °C). High performance achieved with nitrogen removal rate (NRR), nitrogen removal efficiency (NRE), and ammonium conversion efficiency (ACE) were 0.866 kg-N/m3.d, 99.19%, and 98.90%, respectively. The cultivated leachate sludge could perform an anammox process with four anammox species, Candidatus Brocadia fulgida, Candidatus Brocadia sapporoensis, Candidatus Brocadia sp uncultured, Candidatus Jettenia sp with abundance 6.52%, 13.82%, 0.77%, and 0.69%, respectively. These findings contribute to the advancement of biotechnology in wastewater treatment, particularly in tropical countries, and highlight the potential for highly cost-effective technology.

Dynamic Low-Pressure Measurement Using a Fiber Optic-based Fabry-Perot Interferometer

Pronnaruimon Talhakultorn, Saroj Pullteap — Wed, 03 Apr 2024 00:00:00 +0700

A dynamic low-pressure measurement using a fiber optic-based Fabry-Perot Interferometer (FFPI) has been demonstrated in this work. The developed system has been divided into 2 main parts: pressure source and sensing system. The former is a chamber comprised of an elastic diaphragm, which proportionally deflects according to input pressure from an air pump. The FFPI, consequently, detects the material deflection and demodulates the parameter into useful pressure value via the fringe counting technique and Kirchhoff-Love’s plate theory. To validate the performance of the developed system, a reference pressure instrument is utilized while the air pump feeds pressure of 0.34–6.57 mbar with 10 times repeatability into the system. The experimental results indicated that the FFPI can measure the pressure of 0.343–6.568 mbar, while the reference instrument showed the output values from 0.343–6.471 mbar, respectively. Moreover, the average and maximum percentage error in measurement is 1.27% and 2.67%, respectively. The resolution of the FFPI sensor is also analyzed to be approximately 0.05% or 0.0382 mbar/μm over all measurement ranges. Therefore, we conclude that the FFPI has high accuracy, resolution, linearity, and reliability in dynamic low-pressure measurements.

Effect of Cryoprotectants on Quality of Desalted Jellyfish Subjected to Multiple Freeze- Thaw Cycles

Wed, 03 Apr 2024 00:00:00 +0700

A freeze-thaw cycle in frozen products occurs when the temperature fluctuates during storage or transportation, causing drip loss, changes in ice crystal reformation, and textural protein. In practical freezing, using cryoprotectants in frozen products aids in delaying the physicochemical changes. The problem has been found in commercial frozen jellyfish with sesame oil, causing the separating oil and water derived from drip loss of thawed jellyfish protein. This study aimed to select an appropriate cryoprotectant and concentration for frozen jellyfish products. Therefore, this research compared the changes in the physical and textural properties of desalted jellyfish collagen protein soaked in inulin, sucrose, or sorbitol at 1, 5, and 10% and subjected to three freeze-thaw cycles. Results showed increased concentration of each cryoprotectant increased soaking yield. The maximum soaking yields of desalted jellyfish were 2.49 ± 0.54, 2.79 ± 0.82, and 2.78 ± 0.51%, and each cryoprotectant content was 7.18 ± 0.01, 7.54 ± 0.00, and 8.58 ± 0.32% when using static soaked in inulin, sucrose, and sorbitol at 10%. During the freeze-thaw cycle, the retardation of the denatured jellyfish protein from ice crystals increased when desalted jellyfish were immersed in inulin, sucrose, or sorbitol at the maximum concentration of 10%, displaying the drip losses at 27.88 ± 0.45, 29.45 ± 0.35, and 28.56 ± 0.73% that lowered than the control at 56.54 ± 0.64%. The increased repeated freeze-thaw cycles increased the compact structure of thawed jellyfish collagen, supported by microstructure analysis. In summary, inulin at 10% appears to have a cryoprotective effect similar to sucrose and sorbitol and will be a choice for commercial frozen jellyfish-based food menu development.

Effects of Enzyme Treatment and Carrier Agents on Chemical and Physical Properties of Almond Protein-Based Product

Tho Y. G. Nguyen, Ha V. H. Nguyen — Wed, 03 Apr 2024 00:00:00 +0700

There has been an emerging trend towards the research of plant-based proteins over the past few years; however, there has been limited conductive observation of plant-based proteins from almond by-products, as well as the potential of using Flavourzyme and different carrier agents to obtain an instant protein-based powder. The purpose of this study was to investigate the effects of Flavourzyme at various concentrations (0, 0.5, 1, 1.5, 2, and 2.5%) and incubation times (30, 60, 90, 120, and 180 min), as well as carrier agents at different ratios with a 20% total concentration on the physicochemical properties of almond protein-based products using freeze-drying (FD). The results showed a higher protein content (p-value ≤ 0.05) using 1.5% Flavourzyme for 120 min compared to the other levels. There was no significant difference (p-value > 0.05) in the protein retention rate after freeze-drying of the samples. However, the addition of Maltodextrin (MA), Gum Arabic (GA), and Inulin (IN) encapsulants improved the physical and functional characteristics of freeze-dried almond protein-based powder (FDAP). However, the solubility of the powder is moderate. Water-holding-capacity (WHC) and Oil- Holding Capacity (OHC) are inversely proportional, where GA-coated powder is the most hydrophobic (17.72 ± 0.87 mL oil/g) and IN-encapsulated powder is the most hydrophilic (15.00 ± 0.87 mL water/g). In conclusion, IN could be a potential encapsulant for almond protein-based powder, because powder produced from IN or MA: IN is acceptable in terms of physical parameters, and IN can also enhance fiber content in the final product.

Enzyme-Assisted Extraction of Fucosylated Chondroitin Sulfate from Sea Cucumber Holothuria scabra and Bohadschia argus and their Potential in Pharmaceutical Applications

Wed, 03 Apr 2024 00:00:00 +0700

Due to the health benefit of fucosylated chondroitin sulfate (FuCS), the efficient method for extraction of FuCS from raw materials is a crucial issue in reducing the production cost. In this study, enzymatic extraction of FuCS from two species of sea cucumber, Holothuria scabra and Bohadschia argus was undertaken using two protease enzymes, alcalase and papain. Response surface methodology (RSM) was employed in determining the optimal extraction conditions with the highest yield of FuCS concentration. The predicted optimal papain-assisted extraction conditions of Holothuria scabra and Bohadschia argus obtained a predicted FuCS yield of 1609.73 mg/100 g and 444.51 mg/100 g, respectively. To compare extraction efficiencies of two protease enzymes, employment of the RSM optimal conditions to Holothuria scabra resulted in 1538.76 ± 20.26 mg/ 100 g and 1295.50 ± 14.28 mg/100 g of purified FuCS for papain and alcalase, respectively. Whereas Bohadschia argus produced 412.39 ± 10.12 mg/100 g and 461.11 ± 8.45 mg/100 g purified FuCS for papain and alcalase, respectively. The acquired FTIR and NMR spectrums of extracted FuCS showed typical bands of sulfation patterns and were compared to commercial FuCS. The extracted FuCS showed enzyme type dependent antioxidant activity, and significant tyrosinase inhibitory activity than commercial FuCS. It also exhibited similar anti-glucosidase activity as commercial FuCS. Thus, this study reveals potential applications of enzyme-assisted FuCS from sea cucumber in food and pharmaceutical industries.

Evaluation of Anti-Foodborne Bacterial Activity, Digestive Enzyme Secretion, and Antimicrobial Resistant Genes as Probiotic Strains Selection for Industrial Interest

Wed, 03 Apr 2024 00:00:00 +0700

Beneficial microbes, such as probiotic bacteria, are increasingly in demand in the food and feed industry. Lactic acid bacteria and bifidobacteria are commonly used as commercial probiotics, only a few species have been isolated from Southeast Asia areas. This study employed criteria including antimicrobial activity, the release of digestive enzymes, and the absence of antibiotic-resistant (AMR) genes to screen potential local isolates. The results revealed that 4 out of 16 isolates met these criteria, displaying anti-foodborne bacterial activities and a lack of fifty-one tested AMR genes. Furthermore, the four selected isolates demonstrated the production of extracellular digestive enzymes, including amylase, lipase, protease, β-glucanase, and cellulase, with enzyme indices ranging from 1.09–1.31. Among these isolates, two potential probiotics were identified as Bifidobacterium animalis subsp. lactis (strain H9-01) and Lactobacillus reuteri (strain P4-S03). Importantly, both species are approved for use as food and feed supplements in accordance with Thai regulations. This research outlines an approach for screening potential probiotics for industrial-scale applications.

Extraction of Cellulose Nanocrystals and Nanofibers from Rubber Leaves and Their Impacts on Natural Rubber Properties

Wed, 03 Apr 2024 00:00:00 +0700

This study aimed to chemically isolate two distinct types of nanocellulose derived from rubber leaves and investigate their use in natural rubber (NR). The cellulose nanocrystals (CNCs) were obtained through acid hydrolysis, while oxidation with 2, 2, 6, 6-tetramethylpiperidine-1-oxyl (TEMPO) was used to produce cellulose nanofibers (CNFs). The CNCs exhibited rigid and rod-like structures due to the removal of amorphous regions through acid hydrolysis, whereas the CNFs retained flexible, fiber-like morphologies and high aspect ratios. Incorporating CNCs or CNFs into NR improved its tensile properties, with the rigid CNCs enhancing the mechanical properties more than the flexible CNFs. CNC addition resulted in a 40% increase in tensile strength and a 38% increase in Young's modulus of NR. However, elongation at break decreased with filler content. On the other hand, CNF addition improved the elongation at the break without compromising the tensile properties. NR with CNF addition exhibited a 25% increase in tensile strength, a 30% increase in Young's modulus, and a 20% increase in elongation at break. Additionally, the biodegradability of NR nanocomposite films containing CNCs or CNFs surpassed that of unfilled NR film. Notably, a 6-month soil burial test revealed weight losses of 35% and 40% for NR nanocomposite films with CNCs and CNFs respectively, compared to a weight loss of 25% for the unfilled NR film.

Flexural Toughening of Hooked-End Steel Fibers Reinforced Mortars

Wed, 03 Apr 2024 00:00:00 +0700

This paper investigated the effect of hooked-end steel fiber at varying fiber content on the flexural toughening of fiber reinforced cement mortars (FRCM) by using three-point bending tests. In particular, to preserve the mortar workability, three low weight fractions (0.3%, 0.5% and 0.7%) and two cement matrices (M10 and M15) were investigated. The results showed that the mechanical bending behavior of the FRCM increases significantly at increasing fiber content and cement plaster matrix. An important aspect that has been addressed is how the flexural toughening is varied at varying fiber content and the type of matrix. Especially, all composite mortars exhibited a toughness index (TI) in the range of 10–45, indicating a suitable strengthening and toughening effect supplied by the hooked-end fiber addition. The best TI value, equal to 44, was experienced for the M10-D7 batch characterized by 0.7 wt.% of hooked-end steel fibers and an M10 cement matrix. Furthermore, unlike unreinforced concrete where brittle and unexpected failure occurs dominated by a sudden and catastrophic propagation of tensile cracks, the FRCM samples exhibited a ductile behavior with a marked residual post-crack resistance even for composites mortars with low metal fiber content.

Investigations on Agrophotovoltaic System Using Different Crops with Special Attention on the Improved Electrical Output

Rahul Waghmare, Ravindra Jilte, Sandeep Joshi — Wed, 03 Apr 2024 00:00:00 +0700

In an Agrophotovoltaic (APV) system, the same plot of land is used for both agriculture and power production. APV systems are currently being investigated for thermal control of solar PV modules using natural transpiration cooling by cultivated crops. The current research focuses on the experimental studies on a 1 kWp APV and 1 kWp reference system with two different crops cultivated beneath the solar PV modules; an experimental setup was designed and built in Nagpur, India. Two crops, Spinacia oleracea and Solanum lycopersicum (Spinach and Tomato, respectively), were grown below 50% of PV modules, and the thermal and electrical performance of the solar plant was investigated as an APV system. The performance of this APV system was compared with the remaining 50% of PV installation. During this study, the effect of crop height on the performance of the solar plant was also investigated. According to the experiments, the temperature of the solar PV modules in the APV system with Tomato and Spinach was reduced by about 5 °C and 6 °C, respectively, when compared to a reference solar PV system. Additionally, the power plant's production is higher when there is less space between the solar PV module and the crop. To predict the performance of the APV system for any given location and for any given crops a systematic analytical procedure has been formulated. This experimental study shows that for the spinach and tomato crops, a 1 MW APV system would produce 169200 kWh and 187500 kWh more electricity yearly than a reference solar PV plant, respectively. Additionally, the same piece of land would give a comparable crop yield along with improved power generation.

On the Performance of the Extended EWMA Control Chart for Monitoring Process Mean Based on Autocorrelated Data

Kotchaporn Karoon, Yupaporn Areepong, Saowanit Sukparungsee — Wed, 03 Apr 2024 00:00:00 +0700

The extended exponentially weighted moving average (EEWMA) control chart is an instrument for detection. It can quickly identify small shifts in the process. The benchmark for the control chart's performance is the average run length (ARL). In this paper, we present the efficiency of the EEWMA control chart to detect tiny shifts when the observations are autocorrelated with exponential residuals through the explicit formulas of the ARL. The accuracy of the solution was verified with the numerical integral equation (NIE) method. After that, the ARL effectiveness of the ARL on the EEWMA control chart was expanded to compare with the traditional EWMA control chart. Finally, using two real datasets that indicate the percentages of internet users using Windows 7 and iOS, the applicability of the offered method is shown. Our findings support the notion that the EEWMA control chart performs better when using autocorrelated data to track tiny changes.

Pyrolysis of Polyethylene from Plastic Waste using Activated Ende Natural Zeolite as a Catalyst

Gregorio Antonny Bani, Mario Donald Bani — Wed, 03 Apr 2024 00:00:00 +0700

Plastic waste has many complex chemical components. In developing countries, direct incineration is often used to reduce plastic waste, releasing pollutants into the atmosphere. A more environmentally sound alternative is pyrolysis. It can turn plastic waste into an alternative fuel. A catalyst, such as natural zeolite, can reduce the energy used in pyrolysis. However, mineral contaminants must be removed first to get optimum activity. This research was focused on using Ende natural zeolite as a catalyst, determining the properties of the mineral in its activated form. It also investigated the interaction between H-zeolite composition and the operating temperature towards pyrolysis oil yield. The experimental results showed that Ende natural zeolite contained a mixture of mordenite, clinoptilolite, and quartz. After activation and modification, there was an increase in the surface area from 53.17–104.67 m2/g. The average pore radius ranged from 19.96–34.21 Å. There was an increase in the pore volume from 22.01–72.34 cc/g. The total acidity changed from 1.456–5.342 NH3/g. The optimum catalyst concentration was 10% in the pyrolysis of 1000 grams of plastic waste catalyzed by 100 grams of H-zeolite. The oil yield decreased at 15% concentration. The 10% concentration worked best at 400 ℃.

Ultrasound-Assisted Biomimetic Synthesis of MOF-Hap Nanocomposite via 10xSBFLike for the Photocatalytic Degradation of Metformin

Wed, 03 Apr 2024 00:00:00 +0700

High levels of emerging pollutants, such as pharmaceutical compounds like metformin (MET), have been an issue for many years. The effective removal of these compounds from wastewater poses a significant challenge and has spurred interest among researchers. This study aims to integrate two of the prominent research interests in photocatalysis, Metal-Organic Frameworks (MOF), and Hydroxyapatite (HAp), and tests their effectiveness in the photocatalytic degradation of MET. The MOF-HAp was produced using a biomimetic method via 10xSBF-like solution with and without ultrasound assistance at varying biomimetic times. MOF-HAp nanocomposite’s photocatalytic degradation capabilities were tested by degrading MET, considering varying parameters – initial pollutant concentration, catalyst loading, and exposure time. Results showed that a biomimetic time of 6 h synthesized with ultrasound irradiation presented the most promising physicochemical properties for MOF-HAp, as verified by the X-ray Fluorescence (XRF), Scanning Electron Microscope (SEM), Brunauer-Emmett-Teller (BET), X-ray Diffractometer (XRD), and Fourier Transform Infrared Spectroscopy (FTIR) analyses. In the photocatalytic degradation of MET, catalyst loading, exposure time, and initial pollutant concentration were found to have significant effects on the percent degradation. The initial concentration of 8 ppm, catalyst loading of 0.25 g, and 120 min of exposure time produced the highest percent degradation with an average of 82.25%. The findings of this study prove MOF-HAp's potential to effectively degrade organic and pharmaceutical pollutants in wastewater.