Papers by Keyword: Adsorbent

Abstract: This study explores the use of biochar derived from Ketapang (Terminalia catappa) leaf waste, prepared via a hydrothermal process and activated with KOH, as an adsorbent for removing mercury (Hg) from aqueous solutions. The study addresses the environmental challenge of heavy metal contamination using a low-cost, sustainable material. Activation increased the surface area of the biochar from 0.067 to 0.450 m²/g, enhancing its adsorption performance. The hydrothermal process was optimized at 220°C, where the biochar exhibited the highest Hg removal efficiency of 71.05% for a 50 ppm Hg(NO₃)₂ solution. The adsorption behavior was best described by the Langmuir isotherm model, indicating monolayer adsorption on a homogeneous surface. The adsorption mechanism likely involves physical and chemisorption interactions, supported by changes in surface morphology, functional groups, and elemental composition. This study demonstrates the promising application of Ketapang leaf biochar as an eco-friendly adsorbent for mercury removal, with implications for water treatment technologies.

Abstract: The research consists of incorporating CTAB into the layers of the the bentonite structure, integrating acid-treated bentonite with cetyltrimethylammonium bromide (CTAB), and obtaining an organic material adsorbent. The physical and chemical properties of the sample modifications are identified by employing X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and thermogravimetric/thermal analysis (TGA/DTA). The bentonite used in this study was recovered from the Trebia deposit, located on the north-western flank of the Tidiennit massif in the Nador region (northeast Morocco). The composite developed in the present study is a practical adsorbent for the treatment of industrial wastewater. CTAB was successfully inserted into acid-activated bentonite, demonstrating intercalation processes through X-ray diffraction, FTIR, SEM, and TGA/DTA. The modified Bentonite structure showed increased interlayer space due to the introduction of molecules or ions. The TGA/DTA graphs confirmed the hydrophobic alteration of Bentonite, with reduced clay dehydration and a surfactant decomposing on the surface and interlayer spaces. Morphologically, CTAB formed large particles and cavities.

Abstract: The escalating levels of atmospheric carbon dioxide (CO₂) emissions and the consequential threat of global warming necessitate urgent measures for CO₂ reduction. This study explores the development of CO₂ adsorbents from biomass, specifically charcoal derived from empty palm bunches, focusing on the impact of different activating agents and activation temperatures on their properties. The research methodology involves the hydrothermal carbonization of empty palm fruit bunches followed by activation using three different materials: potassium hydroxide (KOH), urea, and a combination of KOH and urea, at three distinct activation temperatures (180°C, 200°C, and 220°C). The investigation encompasses a comprehensive analysis of the functional groups and surface morphology through Fourier-transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) techniques. The findings demonstrate that the choice of activating agent and activation temperature significantly influences the characteristics of the resultant charcoal. Notably, higher activation temperatures lead to reduced lignin content and increased pore distribution. Among the various combinations, the KOH + Urea activating agent at 220°C exhibits the most favorable attributes, including the weakest lignin peak intensity and the highest pore distribution. In conclusion, this research underscores the potential of empty palm bunch charcoal as a promising CO₂ adsorbent, offering insights into optimized conditions for its production. This contributes to the ongoing global efforts to combat climate change by mitigating CO₂ emissions.

Abstract: Emissions are substances that enter the air, whether or not they have the potential as pollutants. Emission gases can have adverse effects on the health of living beings, especially humans, and can contribute to an increase in the Earth's temperature. Therefore, separation efforts are needed to minimize the negative impacts caused by them. Adsorption method was categorized as absorption, cryogenic distillation, and membrane. Although there were shortcomings in adsorbing emission gases through the method, it remained a promising approach. Adsorption was recognized for its economic viability, technological effectiveness, thermally stability, corrosion resistance, high load capacity, and tunable surface properties. However, adsorption materials were categorized as porous carbon, zeolites, metal-organic frameworks (MOFs), porous polymers, and porous silica. A significant limitation of the method was its susceptibility to decreased capacity in the presence of water vapor. The analysis results showed that porous silica became a superior adsorption material due to its high porosity, which facilitated rapid gas diffusion. To enhance selectivity and adjust pore size, material modifications, particularly silica, became necessary. This showed that surface modification for silicasupported the improvements in selectivity and pore size.

Abstract: Industrial wastes such as lead metal can cause serious problems because of their toxic nature and can pollute the environment. To reduce levels of lead metal, you can use a natural adsorbent from activated charcoal on the outer shell of ketapang seeds. The ketapang tree is a type of plant that is often found in the surrounding environment because it is used as a shade for the many falling ketapang seeds making waste in the environment to reduce environmental pollution from the falling ketapang can be used as an adsorbent because it contains cellulose and carbon elements. One alternative to reduce lead levels using adsorbents is through the adsorption process which is the process of adsorption of a solid or liquid that involves physical, chemical and electrostatic interactions between the adsorbate and the adsorbent on the surface of the adsorbent. The adsorption process using activated charcoal adsorbent is one of the most frequently used non-polar adsorbents because it has better adsorption power and surface area than other types of adsorbents. This study aims to determine the influencing variables and the optimum condition of the natural adsorbent from the activated charcoal of the outer shell of ketapang seeds on decreasing levels of metal Pb (NO3)2. The research method used is an experimental method with a two-level factorial design. The results showed that the adsorption temperature was the most influential variable in this study with an optimum yield presentation of 66.77%. The activated charcoal produced has a water content of 8%, ash content of 5.2% and an absorption capacity of methylene blue of 698 mg/g.

Abstract: In this study, we utilized an adsorbent based on rice straw for reducing hexavalent chromium ions (Cr (VI)) in an aqueous solution. The rice straw as adsorbent raw material was washed, dried, and powdered. Rice straw powder was heated at 450°C for 2 hours to obtain rice straw adsorbent. The adsorbent was activated with 1M H₃PO₄ for 4 hours. Characterization of the adsorbent was done using Fourier Transform Infra-Red (FTIR) method. FTIR spectra showed the presence of hydroxy, carboxylic, aromatic, and ether groups on the surface of the rice straw and the made adsorbent. The reduction of Cr (VI) ions in aqueous solutions was carried out using the adsorption batch method. The adsorption process was conducted in various the Cr (VI) solutions pH for 1-5 and variations in contact time for 5-720 minutes. The highest percentage reduction of Cr (VI) reached 66.90%. It has occurred at pH 2 and equilibrium at 600 minutes of contact time.

Abstract: The article is devoted to mathematical modeling and fuzzy logic in controlling the process of adsorption purification of isobutane and isobutylene from impurities. The article also conducted research on the production of high-purity isobutane and isobutylene from the isobutane-isobutylene fraction of pyrolysis gas. A method has been developed for increasing the purity of isobutane and isobutylene fractions isolated from pyrolysis gas using sulfuric acid. It is proposed to introduce adsorption units into the plant technological scheme for separating the hydrocarbons isobutane and isobutylene from the C4 fraction of pyrogas, with the help of which it has been proven to obtain isobutane and isobutylene hydrocarbons of high purity up to 99.9%. The processes of selecting adsorbents for the additional purification of the isobutane fraction from isobutylene impurities were also studied and activated carbon of the AP-3 grade was selected, and for the additional purification of the isobutylene fraction from impurities of normal butylene’s, CaA zeolite was selected. The main reactions have been studied and a mathematical model of the processes for producing pure isobutylene and isobutane has been developed, taking into account recycling; also, artificial intelligence (AI) has been used when selecting adsorbents to optimize the processes of purifying the pyrolysis gas fraction of isobutane and isobutylene from impurities.

Abstract: This study aims to: (1) activate rice husk ash (ASP), coconut shell ash (ATK), and wood charcoal (AK) to become adsorbents and characterize them; (2) purify waste cooking oil (WCO) using ASP, ATK, and AK adsorbents; (3) making biodiesel from the purified WCO and characterizing their quality. This work uses experimental techniques, starting with preparing adsorbents by activating with KOH and characterizing activated ASP, ATK, and AK adsorbents using SEM and FTIR. The adsorbents were then used to purify WCO. Biodiesel was made from purified WCO by transesterification using an H₂SO₄ catalyst in ethanol. The process was carried out at 60°C for 12 hours. Then biodiesel layer was heated to 70°C to evaporate the ethanol. The biodiesel products were tested according to Indonesian National Standard (SNI). The results showed that peaks of the activated ASP, ATK, and AK adsorbents have alcohol groups (-OH), and other functional groups. Activated adsorbents have many pores when compared to adsorbents before activation. Biodiesel synthesized using activated ASP adsorbent has a higher flash point than using activated ATK and AK adsorbents and fulfils SNI specifications.

Abstract: Increased waste as a result of unsustainable industrialization, urbanization, and agriculturalization is a serious threat to the comfort of human life. Our ecosystem has been severely damaged by the production and disposal of massive amounts of harmful materials and pollutants. Technologies must be created to eliminate or drastically reduce hazardous waste and pollutants from the environment. By using agricultural waste and by-products to create environmentally acceptable adsorbents, adsorption is one way for removing pollutants from water and waste water. It is crucial to evaluate the capability of various produced adsorbents and determine how well they can be used to treat water and wastewater. To address this, research is being done on characterizing these materials. Proximate analysis, thermal gravimetric analysis, FTIR, SEM, energy dispersive X-ray analysis (EDS), BET surface area analysis, and X-ray diffraction are used to analyze agricultural wastes. According to XRD studies, agro-based adsorbents have an amorphous structure, which is a benefit for well-defined porous adsorbents. Development of good porosity occurred in all materials due to chemical treatment given to materials, which was evident from SEM images and results of BET analysis. Adsorbents prepared from agricultural wastes had large surface area ranging from 950-1200 m²/g, which makes them efficient adsorbents like conventionally used charcoal. EDS test results also shows that normal carbon content is in range 57 to 59% which is good for adsorption. Proximate analysis and bulk density also supported that developed adsorbents has the great potential. Agro-based adsorbents are efficient adsorbent which is a good alternative to conventionally and commercially available activated charcoal.

Abstract: The population growth and the industrial revolution caused severe environmental pollution, especially pollution of clean water availability. Several ways have been conducted to overcome the pollution of clean water availability, one of which is by the adsorption of metal and cellulose-based waste materials as a hybrid catalyst. This study aims to fabricate and modify a hybrid catalyst composed of cellulose in the form of nanosized fibrils. Cellulose can be used as a catalyst by incorporating Fe from magnetite (Fe₃O₄) and can work effectively as an adsorbent for methylene blue (MB) dye waste. The method used in this research is a modified coprecipitation method by combining cellulose and Fe₃O₄ nanoparticles. Hybrid Catalyst of Fe₃O₄/Cellulose Nanocomposite-Base has been successfully characterized by using XRD, SEM-EDX, and UV-Vis, respectively to determine the particle structure, morphology, and adsorption capacity of the sample. The results of data analysis showed that Fe₃O₄/Cellulose could purify MB solution depending on the ratio of Fe₃O₄ and the mass of cellulose used. The higher the mass ratio of cellulose to Fe₃O₄, the absorbance value of the Fe₃O₄/Cellulose nanoparticle sample increases.