Papers by Keyword: Adsorbent

Abstract: Wood sawdust, one the high volume agricultural wastes in Nigeria, occupies space and constitutes environmental nuisance. Burning, it produces green house gases. Converting it to adsorbents is economical and environmental benign. This work assessed the adsorptive capacities of two Danielliaoliveri sawdust-based adsorbents for the removal of ibuprofen from waste stream. The sawdust was carbonized and activated with ZnCl₂ and H₃PO₄ to produce adsorbents code-named ZCAC and PAAC respectively. The physicochemical properties of the adsorbents were determined and batch adsorption experiments performed. The optimum pH for the adsorption of ibuprofen onto the ZCAC and PAAC was 3. The isotherm studies revealed that the Ibuprofen (IBU)-ZCAC system data fitted Redlich-Peterson and Langmuir models. The data also fitted Pseudo-second order and Boyd kinetics, defined intraparticle diffusion of the adsorbate molecules. The process was physical and endothermic. For the adsorption onto PAAC, the data fitted the Freundlich and the Halsey models. The data also fitted the Pseudo-second order and the Elovich kinetics. The process was endothermic. The adsorption capacities of ZCAC and PAAC for IBU were 3.876 and 15.385 mg/g respectively. ZCAC and PAAC were promising adsorbents for remediation of wastewater contaminated with ibuprofen.

Abstract: In this study, iron removal was carried out by the adsorption process as a well-known method of removing heavy metal. Natural bentonite with magnetic properties in a monolithic form or Magnetite-Bentonite-based Monolith (MBM) adsorbent was used as an adsorbent to remove Iron (II) ion from the aqueous solution. The magnetic properties of adsorbents are obtained by adding magnetite (Fe₃O₄), which is synthesized by the coprecipitation process. The characterization of magnetic properties was performed using the Vibrating Sample Magnetometer (VSM). VSM results showed that the magnetic particles were ferromagnetic. Adsorption efficiency, isotherm model, and adsorption kinetics were investigated in a batch system with iron solution concentration varied from 2 to 10 mg/L and magnetite loading at 2% and 5% w/w. The highest removal efficiency obtained reached 89% with a 5% magnetite loading. The best fit to the data was obtained with the Langmuir isotherm (non-linear) with maximum monolayer adsorption capacity (Q_o) at 5% magnetic loading MBM adsorbent is 0.203 mg/g with Langmuir constants K_L and a_L are 2.055 L/g and 10.122 L/mg respectively. The pseudo-first-order (non-linear) kinetic model provides the best correlation of the experimental data with the rate of adsorption (k₁) with magnetite loading 2% and 5%, respectively are 0.024 min^-1 and 0.022 min^-1.

Abstract: This paper dwells upon finding the specific surface area of cake, a coal enrichment waste, exposed to electroplasma treatment; the goal is to make an organomineral porous material to be used as a sorbent for wastewater treatment. The research team used a monomolecular Langmuir adsorption model and surface tension of the surfactants before and after adsorption at the interface of solution and solid adsorbent. Another process considered herein was thermal activation of substances in the electroplasmic reactor for making organomineral porous materials from coal cakes. The paper presents the resulting specific surfaces area of the organomineral sorbent thus produced. Thus, the waste of flotation, i.e. coal cake, is fundamentally suitable for making porous substances by thermal destruction in an electroplasma reactor.

Abstract: The removal of mercury from the waterbody remains a severe challenge in ensuring environmental safety due to its highly toxic and non-biodegradable properties. Adsorption is an evidently effective method for heavy metal removal in water. This research aims to study the mercury (II) ion adsorption behavior in aqueous solution onto extruded natural bentonite in monolithic structure, bentonite-based monolith (BBM) adsorbent. BBM was characterized by XRD, BET, and SEM, the results verify BBM could improve adsorption performance assumed on its structure. Adsorption efficiency, isotherm model, and adsorption kinetic were investigated. Experiments were performed in a lab-scale batch reactor with mercury solution concentration varied from 1 to 5 mg/L. The maximum adsorption efficiency discovered to be 63,9%. The experimental data fitted well to Langmuir isotherm (non-linear) and kinetic model pseudo first order (non-linear), revealing the maximum monolayer capacity (Q_o) of BBM to be 0,187 mg/g with Langmuir constants K_L and a_L are 0,215 L/g dan 1,151 L/mg respectively. These value confirms that BBM adsorbent encompasses tremendous potential for mercury (II) ion removal in a solution.

Abstract: An environment is said to be polluted if there have been changes in the environmental order so that it is no longer the same as its original form, as a result of the entry and inclusion of a foreign substance or object in the environmental order. Various cases of heavy metal pollution have been reported in both developed and developing countries, as well as adverse effects on the population living in the vicinity. This heavy metal pollution including cadmium metal. Generally, the contamination of cadmium in waters originates from the waste of the metal ore processing industry. Cadmium which accumulates in the body of living things has a long half-life and generally accumulates in the liver and kidneys. This study focuses on reducing levels of heavy metals in the environment with an adsorbent from natural products, namely palm oil empty fruit bunches and humic acid from peat soils. This research combines two adsorbents of natural products, namely by immobilizing cellulose and humic acid with the epichlorohydrin crosslinker agent. The purpose of this study was to determine the effect of the optimum dose of epichlorohydrin on cellulose and humic acid immobilization, determine the optimum pH, adsorption isotherm, cadmium metal adsorption kinetics and determine the type of interaction between adsorbent and adsorbate. The results showed a link between cellulose and humic acid which was connected via epichlorohydrin from FT-IR results in certain wavenumbers, including OH vibration (3415cm^–1), stretching CH vibration (2903 cm^–1), NH bending vibration (1625 cm^–1), COO stretch vibration (1373 cm^–1) and CO stretch vibration (1058 cm^–1). For the optimum dose of epichlorohydrin obtained at 15 mL (1 recipe) with an adsorption capacity of 7.4705 mg/g. While the optimum pH was obtained at pH 6, the adsorption isotherm obtained the largest capacity at 200 ppm by following the Freundlich isotherm (R² = 0.9512).

Abstract: Calcium-looping technology is defined as one of the most desirable methods of carbon capture, utilization and storage (CCUS). However, because of sintering, rapid deactivation of CaO-sorbents is currently a major barrier to this technology. The stability of calcium based sorbent may be enhance by incorporating them with inert support materials such as MgO, Al₂O_2, ZrO₂ and SiO₂. For this study, calcium based sorbent has been incorporate with silica obtained from rice husk ash. CaO-SiO₂ sorbents are prepared using physical dry mixing method which is much simpler compared to other available methods. The prepared CaO-SiO₂ sorbents were then characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD). New crystalline phase, larnite (Ca₂SiO₄) was detected in XRD patterns and this phase possess good chemical durability and may help to prevent sintering effect of calcium based sorbents and enhance their cyclic capability. CaO-SiO₂ sorbent calcined at 700 oC with different grinding times have highest intensity of XRD peak at (104) with element of calcite. Sorbents with different weight composition of CaCO₃-RHA were observed to have different surface morphology. SEM images of the sorbent (90wt% CaCO₃-RHA) before calcination showed bigger particle size with irregular shape and more porosity. Then, SEM analysis was conducted for samples with different grinding times after calcination. CaO-SiO₂ sorbents with 20minutes grinding time exhibited small size of particles with some porosity. Besides that, the particles are well distributed without agglomeration occured. The CaO-SiO₂ sorbent calcined at 700 oC sorbents were tested for 20 consecutive carbonation and calcination cycles using Thermogravimetric Analysis (TGA). CaO-SiO₂ sorbent treated with 700 oC calcination temperature and 20 minutes of grinding shows better cyclic CO₂ sorption capacity.

Abstract: IIn this work, it was evaluate the utilization of mussel shells (raw and calcinated) as a permeable reactive barrier (PRB) for the treatment of municipal sewage sludge (MSS) contaminated with heavy metals, creating a novel combined system, which integrates two technologies: electrokinetic remediation technology, and adsorption by the utilization of mussel shells adsorbents. Regarding the adsorption process into the mussel shells adsorbents, it was also aimed to study the influence of aragonite and calcite on the adsorption of lead (Pb), copper (Cu), chromium (Cr), and zinc (Zn). For the preparation of the PRB, it was used three adsorbents: MEXMT (raw mussel shells); MEXMT 600 (mussel shells calcinated at 600°C) and finally, a commercial calcium carbonate (CCCom). It was applied an electric current of 1 V cm^-1 and it was used an adsorbent/sludge ratio of 30 g kg^-1 of contaminated sludge for the preparation of the PRB. Results proved that this process is perfectly suited for the removal of the heavy metals understudy from the sludge, especially with MEXMT (raw mussel shells) adsorbent. With this adsorbent, at the end of the 92 hours of operation time, it was obtained high removal rates for each metal in study. Results demonstrate that higher removals rates were achieved in lead (92%), followed by zinc (82%), copper (76%), and finally chromium with 72%. Based on these results, it was proved the technical viability of the proposed technology (electrokinetic remediation with raw mussel shells as a permeable reactive barrier) to treat municipal sewage sludges.

Abstract: Textile industry is commonly use dyes in colouring process which become the major dye wastewater source that leads to serious pollution in the environment. The disposed dyes can lead to serious harm to the water users and life in the aquatic because of the dye properties. Hence, the dye adsorption by activated carbon prepared from foxtail palm fruit was studied. The objectives of this study were: 1) to prepare activated carbon from foxtail fruit palm and 2) to study the effect of contact time, adsorbent dosage and initial concentration of dye usage toward the efficiency of the prepared activated carbon. Nitric acid was used as activating agent in this experiment, with impregnation time of overnight and 500 °C of 2.5 hours carbonization. The adsorption capability of foxtail fruit palm activated carbon as activated carbon was determined with the use of a dye called methylene blue. The results showed that 5 g of activated carbon was used to reduce 97.1% of 2 mg/L methylene blue with 150 minutes contact time. This result aligns with the SEM result which indicated that the produce activated carbon is rich with well-developed and irregular size of pores ranging between 1.585 μm to 7.556 μm. This study indicates that activated carbon from foxtail palm fruits could be utilized as an alternative activated carbon to treat dye wastewater.

Abstract: This study explored adsorptive property of ceria nanocrystal as an adsorbent for amoxicillin removal from water. Ceria nanocrystal was synthesized by employing precipitation method and characterized by using XRD and N₂ adsorption-desorption analysis. The adsorption experiment was performed by managing amoxicillin in natural condition. Then, parameters in the adsorption experiment, such as adsorbent dosage, contact time, temperature and initial concentration of amoxicillin are varied. The XRD pattern illustrated that the average crystallite size of ceria nanocrystal formation was 13.08 nm. N₂ adsorption-desorption analysis showed that ceria nanocrystal was mesoporous with specific surface area of ​​65.26 m²/g. The amoxicillin adsorption of ceria nanocrystal adsorbent was described by Langmuir isotherm model with maximum adsorption capacity of 37.17 mg/g. The adsorption kinetic of ceria nanocrystal corresponded to the pseudo-second order model. Removal efficiency of amoxicillin by ceria nanocrystal was approximately 80% within 60 minutes over temperature range 303-323K. Those parameter results are described that ceria nanocrystal adsorbent is feasible as a rapid amoxicillin removal from water.

Abstract: Among the numerous materials used for dye removal, magnetite is particularly interesting due to its ability to act as an adsorbent and a Fenton catalyst, being easily separable by application of a magnetic field and reusable. Herein, we describe a co-precipitation–based synthesis of magnetite nanoparticles (particle size = 11 nm, surface area = 147.12 m² g^–1) from iron sand and investigate their effectiveness for methylene blue (MB) degradation. The above nanoparticles could promote the decomposition of MB both in the dark (via adsorption) and under UV light irradiation (via Fenton-type degradation), exhibiting the additional advantage of recyclability. Thus, MB degradation efficiencies are 76.32, 76.08, and 68.52% for first, second, and third cycles, respectively, indicating that the prepared magnetic material is a promising recyclable catalyst for the decontamination of dye-containing wastewater. The photo Fenton reactions take to account for reproducibility of MB degradation.