7 research outputs found
Coconut fiber and fly ash polymer hybrid composite treated silane coupling agent: Study on morphology, physical, mechanical, and thermal properties
No full textComposite materials made from natural ingredients are currently being developed by researchers as materials that are more environmentally friendly. Hybridization techniques used in making composite materials continue to progress, involving the combination of several raw materials with similar or different properties, such as organic/organic, organic/inorganic, and inorganic/inorganic. In this research, coconut fiber which is an organic material is combined with fly ash which is an inorganic material. The contrasting properties of these two raw materials prompted the evaluation of their combination by including a silane coupling agent, which facilitates the bonding of organic and inorganic components. The essence of this research is to test the effect of adding silane coupling material on several parameters, namely physical properties (density, water absorption, and thickness swelling), mechanical properties (tensile strength, tensile modulus, elongation, and flexural strength), and thermal properties. To prepare coconut fiber, alkaline treatment is used to remove hemicellulose and lignin. Then, the coconut fiber was soaked in a 5 % vinyltrimethoxysilane (TVS) solution by weight. The addition of silane coupling material affects the physical properties of the composite resulting in a decrease in water absorption by 33 % and a decrease in thickness swelling by 0.3 %. The inclusion of silane coupling agent led to an increase in tensile strength, tensile modulus, and flexural strength, while elongation decreased by 20 %. Thermal properties analysis showed that the silane treatment affected the decomposition of the composite material, reducing it by 2 % from 90 % without the coupling agent to 88 % with the coupling agent
Enhancing Diatomaceous Earth Characteristics for Adsorption of Heavy Metals from Acid Mine Drainage: The Impact of Dual Activation Process
No full textThis study investigates the effects of dual activation methods, including physical and chemical processes, on the characteristics of diatomaceous earth (DE) for the purpose of controlling heavy metal concentration in acid mine drainage. The DE is subjected to physical activation through calcination at 750 oC for 60 minutes, followed by chemical activation using 1N HCl at 80 oC for 24 hours under magnetic stirring. The resulting adsorbent is then characterized using XRD, SEM-EDX, and BET instruments. The analysis reveals that the dual activation methods increase the silica content and eliminate impurities in the DE, leading to a more amorphous structure with decreased crystallinity. The physical activation increases the surface area, while the dual activation process reduces the surface area and increases pore size. These findings provide valuable insights into the adsorption capacity of DE for reducing heavy metals in acid mine drainage
Cigarette butt filter as membrane material with tannic acid and FeCl3 additives for improve antifouling properties
No full textMembrane fouling remains a critical challenge in wastewater treatment, particularly in applications involving oil-water emulsions. This study addresses this issue by fabricating antifouling membranes from repurposed cigarette filter waste, modified with tannic acid and FeCl3 (ferric chloride) coatings. These modifications enhance membrane hydrophilicity, antifouling properties, flux recovery, and selectivity through an environmentally friendly approach. The membranes were prepared using the non-solvent induced phase separation (NIPS) method and subsequently coated through vacuum filtration. Key performance metrics included pure water flux, oil emulsion selectivity, and antifouling properties. The antifouling mechanism was attributed to the hydrophilic and protective layers formed by the tannic acid and FeCl3 modifications, which reduced fouling and improved flux recovery. Characterization revealed that the tannic acid and FeCl3 modifications created a hydrophilic layer with uniform pore distribution, leading to an oil rejection rate of up to 97 % and an increased flux recovery ratio of 85 %, compared to 65 % in unmodified membranes. The results highlight the potential of waste-derived membranes as a sustainable alternative for industrial wastewater treatment, aligning with the principles of circular economy and green chemistry. Future work should explore long-term stability, surface charge effects, and optimization of additive concentrations to enhance performance and antifouling efficiency further
Enhancing polyethersulfone membrane durability and stability through Eco-friendly green silica from natural kaolin for water treatment applications
No full textMembrane technology is pivotal in addressing global water scarcity; however, issues such as membrane fouling and chemical degradation significantly hinder its operational efficiency and longevity. This study investigates the use of eco-friendly green silica derived from natural kaolin as an additive to enhance the performance of polyethersulfone (PES) membranes fabricated via the phase inversion method. Seven membrane compositions were developed, incorporating varying concentrations of both green silica and commercial silica, to allow a direct performance comparison. The membranes were systematically characterized for hydrophilicity, porosity, pore size distribution, and mechanical stability, while their filtration performance was evaluated in terms of water flux, humic acid (HA) rejection, fouling resistance, and chemical stability.The findings revealed that green silica enhanced membrane hydrophilicity and porosity at optimal concentrations, leading to improved fouling resistance and cleaning efficiency. Notably, the membrane containing 1 % green silica (M-K3) exhibited a high HA rejection rate of 98.37 % with a moderate water flux of 10.85 L/m²·h, balancing selectivity and permeability. In contrast, membranes containing 1 % commercial silica (M-S3) showed higher water flux (86.83 L/m²·h) but lower HA rejection (73.75 %), highlighting a trade-off. Green silica-modified membranes also demonstrated superior chemical stability, maintaining consistent performance under extended filtration and exposure to cleaning agents. These results underscore the potential of kaolin-derived green silica as a cost-effective, sustainable, and high-performance alternative to commercial additives in water treatment membranes
Preparation of tungsten trioxide/graphene oxide/ hydroxyapatite (WO3/GO/HAp) for photocatalytic removal of methylene blue under visible light
No full textThe textile industry is one of the leading contributors of liquid waste in the form of synthetic dyes, which significantly contaminate water sources. Heterogeneous photocatalysts employ semiconductors that trigger photocatalytic processes with the assistance of UV or visible light to degrade waste. Tungsten trioxide (WO3) is a potential semiconductor with a small band gap (2.8 eV) that absorbs visible light. WO3 was combined with graphene oxide (GO) and hydroxyapatite (HAp) to exploit the ultrasonication method to degrade methylene blue (MB) dye. The results of the SEM-EDX characterization confirm the constituent elements of the WO3/GO/HAp material. The chemical elements were confirmed by energy-dispersive X-ray spectroscopy. The ability of the original and modified WO3 photocatalysts (WO3/HAp, WO3/GO and WO3/GO/HAp) to degrade 15 ppm of 50 ml of MB solution at concentrations of 10, 15, and 20 mg for 4 h under visible light was investigated. The breakdown of the methylene blue dye demonstrated that the reaction speed followed a first-order pattern. Meanwhile the adsorption isotherm better fit Langmuir for WO3/GO and WO3/GO/HAp. The highest pollutant degradation was achieved using 20 mg WO3/GO and WO3/GO/HAp photocatalysts, which achieved efficiencies of 99.1 % and 98.3 %. These results confirm that the WO3/HAp; WO3/GO, and WO3/GO/HAp hybrid photocatalysts exhibit better degradation performance than unmodified WO3 photocatalysts. Additionally, these photocatalysts can be reused up to three times without experiencing substantial loss in effectiveness
Hydrophilic Antimicrobial Polyethersulfone Membrane for Removal of Turbidity of Well-Water
No full textMembrane-based technologies have been widely used for surface water treatment. Yet, many aspects of this technology can still be improved. This study aims to develop polyethersulfone (PES)-based phase-inverted membranes to improve the morphological structure, antimicrobial properties, and performance by incorporating Poloxamer 188 and patchouli oil as the dope solution additives. The performance of the membrane was assessed for filtration of well water and by evaluating the turbidity rejection. This study used a phase inversion technique in the membrane manufacturing process with PES, PES + P188 + 1 wt% PO, PES + P188 + 3 wt% PO, and PES + P188 + 7 wt% PO. The characteristics of the obtained membranes were studied in terms of structure and morphology, microbial growth prevention, hydrophilicity, filtration flux, and ability to reduce the turbidity of well water samples. Results show that the addition of Poloxamer 188 and patchouli oil in the dope solution turned the membrane more porous (up to 73.24% increase in porosity) and more hydrophilic (the water contact angle (WCA) was lowered from 70 to 37°). The additives also increased the antibacterial properties of the membrane, as shown by up to 97.5% reducing Escherichia coli colonies on the membrane surface. Overall, the results demonstrate significant improvements in the characteristics and performance of PES membranes by incorporating Poloxamer 188 co-polymer and patchouli oil as additives in the dope solution. The modified membrane was successfully applied to remove turbidity from a water sample. The turbidity parameters in well water samples could be fully reduced in nine out of ten samples by the membrane containing 7 wt% PO additives
Exploring the effect of CNTs and pluronic on characteristics and stability of polyethersulfone (PES) and polyvinylidene fluoride (PVDF) membranes
No full textThe accumulation of organic matter and colloidal particles on the membrane surface during the filtration process requires periodic chemical cleaning, potentially impacting the membrane properties and characteristics. Unfortunately, in recent years research into membrane stability against cleaning agents has often been neglected. This should be a crucial part to be prepared as membrane use in the industrial world, therefore this research aims to study the aging of polyethersulfone (PES) and polyvinylidene fluoride (PVDF) membranes modified with single-walled carbon nanotubes (CNTs) and Pluronic (PF). Membranes were prepared using phase inversion method and then treated by soaking in a 5 % sodium hypochlorite (NaClO) solution for 1 hour. Changes in the properties and performance of each membrane were investigated before and after treatment. Overall, the results show that the modified CNTs/PF-PES has better stability in various aspects of analysis such as functional groups, chemical composition, morphology, and hydrophilicity. The CNTs/PF-PES water contact angle increases from 59.4° to 64.7° while CNTs/PF-PVDF water contact angle increases until 69.1°. In addition, CNTs/PF-PES performance also shows more stable results with a flux decrease of 1.31 L/m2.h only, while CNTs/PF-PVDF experiences a decrease of up to 16.31 L/m2.h. Therefore, it can be concluded that CNTs and PF modification is better and more stable on PES membrane matrix compared to PVDF.Published versionThe Indonesian Ministry of Education, Culture, Research, and Technology is acknowledged for funding this study under PDUPT grant (062/E5/PG.02.00.PL/2023)
