Papers by Keyword: Adsorbent

Abstract: Lead waste that pollutes the environment can cause a variety of serious diseases. Various efforts have been made to remove lead waste from the environment, one of which is through the development of magnetic nanoparticles-based adsorbents. In this work, the synthesis of ZnFe₂O₄-PEG/RGO nanocomposites was carried out through co-precipitation and sonochemical methods. The structure, morphology, function groups, and adsorption performance of the ZnFe₂O₄-PEG/RGO nanocomposites were characterized using XRD, SEM, FTIR, and AAS. X-ray diffraction pattern showed the formation of a single phase ZnFe₂O₄ with a cubic spinel structure. The RGO peak was not detected because the RGO mass was much smaller inside the ZnFe₂O₄-PEG/RGO nanocomposites. Furthermore, refinement analysis through Rietica software obtained crystallite size of ZnFe₂O₄-PEG/RGO were 9.6 nm. The SEM result showed that the morphology of ZnFe₂O₄-PEG tends to be spherically distributed on RGO. Based on FTIR results, the functional groups of ZnFe₂O₄-PEG/RGO nanocomposites showed the presence of Zn-O and Fe-O bonds at 529 cm^-1 and 428 cm^-1. Meanwhile, C-O bonds at wavenumbers 1222 cm^-1 showed typical absorption of RGO. Despite Fe-O and C-O bonds, the presence of C-O-C bonds at wavenumbers of 1031 cm^-1 indicates the characteristics of PEG that successfully coats ZnFe₂O₄ nanoparticles. Interestingly, the AAS results showed that ZnFe₂O₄-PEG/RGO nanocomposites had an excellent performance as lead adsorbents, evidenced by the percentage of adsorption up to 97,7%.

Abstract: Zeolite Pahae an adsorbent material by activating physical and chemical processes has been synthesized. The methods used are ball milling and coprecipitation methods. Zeolite was ball milling and activated, then sieved using 100 mesh and 200 mesh sieves. To obtain nanozeolite, a ball mill and coprecipitation were carried out to obtain a size of 9.08 nm. The X-Ray Diffraction (XRD) results showed that the zeolite structure is tetragonal. Zeolite is used as a heavy metal adsorbent. Atomic Absorption Spectroscopy (AAS) method can determine how much zeolite can absorb heavy metals. The results of the AAS test showed that the absorption of nanozeolite to heavy metals was Pb of 99.81%; Fe is 99.99% and Mn is 96.87%. The absorption of 200 mesh zeolite is Pb of 99.45%; Fe is 99.99% and Mn is 99.61%. The absorption of 100 mesh zeolite is Pb of 99.66%; Fe is 99.98%, and Mn is 99.68%. From these results obtained zeolite particle size affects the absorption of heavy metals.

Abstract: Dye pollutants are commonly found in waste water, posing a health risk. Adsorption is a potential technique for dye removal, because of its long-term viability, bio-adsorption is favored. Bio-adsorbent derived from local sources provides a long-term production supply. However, there is a wide range of bio-adsorption, which leads to differences in bio-adsorbent kinetics and characteristics. Tanjung fruit (Mimusops Elengi) peels are used to make activated carbon with a large specific surface area and high porosity. This fruit is one of the readily accessible native fruits in East Kalimantan. The effects of three activators (H₃PO₄, NaCl, and KOH) were studied. Characterization and analysis is conducted by Scanning Electron Microscopy (SEM) for surface morphology analysis and BET method for porosity analysis.The results reveal that acid activation (H₃PO₄) was successful in producing highly porous activated carbon, which has greater adsorption performance than salt (NaCl) and alkaline activation (KOH). The use of salt (NaCl) as an activating agent resulted in a greater development of broad porosity during the activation thermal treatment that followed. The carbon was activated at 500°C had a BET surface area of 587.59 m²g^-1 and a pore size of 28.27 ml g^-1, respectively. For isothermal and kinetics, the Langmuir model and pseudo-first-order reaction are the best fit models. Our findings provide important information on the guided synthesis of large-surface-area, extremely porous activated carbons from local biomass waste, which has a potential for adsorptive dye removal.

Abstract: This study aims to determine the optimal conditions of acid-activated clay adsorbent in adsorption of Pb²⁺ metal ions. Clay was taken around East Kalimantan, Karang Joang. This adsorbent was prepared by mixing clay into a solution of KMnO₄, H₂SO₄ and HCl successively, and stirred for 4 hours at a temperature of 80°C. The morphology and active groups of the adsorbent were analyzed using BET and FTIR. The variables of this study were the mass of the adsorbent 0.1, 0.3 and 0.5 grams and the contact time of 5, 30 and 55 minutes. Adsorption capacity of this adsorbent was analyzed using Atomic Absorption Spectrophotometry (AAS). The results of this study indicate that the optimum mass of adsorbent is 0.1 g, and contact time is 30 minutes. Adsorption capacity of Pb²⁺ metal ions by acid-activated clay adsorbent at the optimum condition of 0.1 gram was 23,585 mg/g and adsorption energy was 2,338 kJ/mol. Meanwhile, at the optimum condition for 30 minutes, the adsorption capacity was 0.771 mg/L, and the adsorption energy was 2.895 kJ/mol. So that the adsorption process in this study can be known, namely physical adsorption because the adsorption energy value is less than 40 kJ/mol.

Abstract: The menace of the disposal of agricultural wastes and water contamination is on the increase. Thus, the need to find a way to recycle these agriculture wastes and make water safe for use. In this study, raw Peanut shell (PSH) and Carbonized Peanut Shell (CPSH) were used as biobased adsorbents in the decontamination of methylene blue (MB) dye from solution. The prepared materials were characterized by SEM, FTIR, XRD, and BET surface area analysis. The batch adsorption method was selected in the MB removal process to maintain adsorbent dosage and dye concentration. The surface area was increased from 1.03 to 34.96 m²/g. also the pore diameter reduced form macropore (93 nm) to micropores (2.39 nm) after carbonization. The CPSH has an adsorption capacity of 104 mgg^-1 and about 90% removal of the 50 mg/L MB with 40 mins at a pH of 6.5. The pseudo-second-order kinetic model best suits the adsorption performance of the CPSH adsorbent. Also, the dye adsorption procedure onto the PSH corresponds to the Langmuir isotherm while the CPSH best fitted with the Freundlich isotherm. This study presents PSH as an alternative resource for the preparation of a cheap and efficient adsorbent from agricultural waste for the removal of laden dye.

Abstract: Textile dyes which are known to be poisonous, mutagenic, and carcinogenic to human health and the environment are found in water bodies, posing a severe environmental threat. The well-known adsorption approach, which uses low-cost agricultural waste as an adsorbent, has recently been extensively explored for water remediation. The ability of tea waste (Camellia Sinensis) species treated with alkaline-potassium hydroxide (KOH) to adsorb methylene blue (MB) dye from dye-contaminated wastewater was investigated. The influence of experimental parameters including pH, initial dye concentration and contact time, temperature and adsorbent dosages on the alkaline-KOH treated tea waste adsorption process were studied. SEM and FTIR were used to characterize the KOH treated tea waste adsorbent. The pH 10 condition was shown to be the best for attaining the highest percent of methylene blue removal. The optimal adsorption for methylene blue was greatly detected at 120 minutes of 100 mg/L. The removal of methylene blue was excellent at a temperature of 60 °C and 0.1 g of KOH treated tea waste dose was chosen as the most favourable for the adsorption of methylene blue. Finally, the synthetic wastewater was examined under optimal conditions and recorded 97 % methylene blue removed.

Abstract: Carbon-based materials are widely used in various fields such as wastewater treatment, gas sensing, and energy storage applications. In this study, waste peanut shell (PSH), available in Egypt, were transformed into useful materials by physical, chemical, and thermal treatments. The physical properties of materials from the different processing combinations were investigated. The activated (APSH), carbonized (CPSH), and activated/carbonized (A/CPSH) forms were successfully prepared. The prepared solids were characterized by SEM, FTIR, XRD, and nitrogen gas adsorption. Ball milling at 5 runs for 45 min resulted in 84 wt% of the ground PSH passing through the 212 μm mesh. Accordingly, the activation, carbonization, and activation/carbonization increased the surface areas of resulting solids by 6, 34, and 580 times, respectively. Among the materials prepared, the activated/carbonized PSH had a mean pore diameter of 1.9 nm, mesoporous material, and the highest electrical conductivity of 0.0042 Ω^-1cm^-1. This PSH is available as adsorbent in water treatment and materials for gas sensing and energy storage.

Abstract: The first stage to prepare bagasse ash to be synthesized. Furthermore, it will be in a furnace at a temperature of 600°C for 4 hours, then analyzed by SEM, BET, EDX, XRF to determine the morphology, surface area, elements and compounds contained in bagasse ash. The second stage is calcined using H₂ gas stream, then TGA analysis. The third stage results from calcination, then hydrothermal with the addition of a molar variation of 10Na₂O:xAl₂O₃ 15SiO₂: 300H₂O namely mixing 3.06 grams of Al₂O₃, 3.168 grams of NaOH, 1.908 grams of silica from bagasse ash and 20.87 grams of H₂O (pH=7). Then the sample will be analyzed using XRD and SEM. The next step will be to test zeolite Y which is synthesized into a metal solution medium, namely Pb²⁺ 25 ppm. The results of the XRF of bagasse ash contained a SiO₂ content of 54% which can be used as a synthetic zeolite with a surface area of 291,761 m2/g, after being synthesized, the surface area of ​​zeolite Y is 648,178 m²/g and % adsorption 97.43% for Pb metal. While commercial zeolite has a surface area of ​​133.122 m²/g with adsorption % 98.84%.

Abstract: Cooking oil saturation due to frequent use for frying will result in a higher fatty acid content. Activated carbon made from the banana peel (Musa acuminata) with micro-mesoporous specifications can absorb free fatty acids. Banana peels are pyrolyzed into charcoal then activated alkaline at a temperature of 650°C. Then the activated carbon is washed and mashed to obtain activated carbon powder as an adsorbent by batch. FTIR carried out adsorption analysis on cooking oil to reduce carboxylic acid in used cooking oil. The regeneration process is carried out using surfactants to save on the use of necessary materials so that they need to be recycled. The experimental results based on isothermic equilibrium show that the Freundlich model can describe the adsorption process well at 28°C with a maximum adsorption capacity of 10 mg/g. The lifespan of activated carbon can only be extended once regeneration, reaching an adsorption capacity of 65% of fresh activated carbon's ability.

Abstract: With a geological reserve of over 170 billion tons, coal is the most abundant energy source in Mongolia with six operating thermal power stations. Moreover, in Ulaanbaatar city over 210000 families live in the Ger district and use over 800000 tons of coal as a fuel. The three thermal power plants in Ulaanbaatar burn about 5 million tons of coal, resulting in more than 500000 tons of coal combustion by-products per year. Globally, the ashes produced by thermal power plants, boilers, and single ovens pose serious environmental problems. The utilization of various types of waste is one of the factors determining the sustainability of cities. Therefore, the processing of wastes for re-use or disposal is a critical topic in waste management and materials research. According to research, the Mongolian capital city's air and soil quality has reached a disastrous level. The main reasons for air pollution in Ulaanbaatar are reported as being coal-fired stoves of the Ger residential district, thermal power stations, small and medium-sized low-pressure furnaces, and motor vehicles. Previously, coal ashes have been used to prepare advanced materials such as glass-ceramics with the hardness of 6.35 GPa, geopolymer concrete with compressive strength of over 30 MPa and zeolite A with a Cr (III) removal capacity of 35.8 mg/g. Here we discuss our latest results on the utilization of fly ash for preparation of a cement stabilized base layer for paved roads, mechanically activated fly ash for use in concrete production, and coal ash from the Ger district for preparation of an adsorbent. An addition of 20% fly ash to 5-8% cement made from a mixture of road base gave a compressive strength of ~ 4MPa, which exceeds the standard. Using coal ashes from Ger district prepared a new type of adsorbent material capable of removing various organic pollutants from tannery water was developed. This ash also showed weak leaching characteristics in water and acidic environment, which opens up an excellent opportunity to utilize.